BA 777 landing accident at LHR

[landing-gear]

Time. 13.15 hrs Thursday 17th January

Breaking news that a Chinese 747 has landed short of the runway at London Heathrow.
Airport is shut as far a i know at the moment.

More info as i get it

[landing-gear]

It was a British Airways B777 flight from China.

Hope there were no serious injuries? Picture on Sky news website.

[Shaggy]

3 Treated for minor injuries. It landed just in front of the fence on 27L. It came to rest just to the right of the 27L numbers. I guess from the pictures on TV is under carridge went at about 20Metres as they dug in, it then slid probably another 400M - 600M before comming to rest.

[gdg9]

http://www.cnn.com/2008/WORLD/europe/01/17/heathrow.incident/index.html

[DAL767-400ER]

Good thing no one was seriously hurt, this could have ended very ugly. Gotta wonder what happened on board that lead to the jet landing several hundred meters short.

Of course, you can always count on CNN to do their work correctly - quote from the article:
A spokesman for Heathrow -- the world's busiest airport

[pilotgolfer]

After looking at that last picture on CNN, wow.

Looks like a pic just made it to the db.
[photoid=6152403]

[AlanF]

Reports are coming through that it had total on board systems failure

[BA747-436]

At this point id like to congratulate the crew for getting the plane down without any serious injuries. Knowing the area around LHR, if that huge 777 had landed any earlier the casualties could have been catastrophic. Even putting it down on the runway in the condition it was in could have resulted in a far worse outcome giving how busy LHR is with traffic.

[BA747-436]

Just to add another point. I flew that exact plane to Sydney via Singapore just over two weeks ago. Daaaam. . .

[Shaggy]

I flew it to NYC in March :) Was it YMMM?

[BA747-436]

Yeah mate it was. 'Was' being the operative word lol.

[Shaggy]

Scary!!!!

[DTVAirport]

Looks like the crew have made all the difference!

[BA747-436]

Reports are that all power was lost around 500ft...

In any case, this won't do BA's current reputation any good what with the huge management screw up with cabin crew reaching maximum hours and flights having to be cancelled worldwide either. I was on a flight back from NRT last week that was subsequently axed due to 'operational reasons'. I can see a sharp dive in share price on the not so distant horizon...

[FlyingPhotog]

Reports are that all power was lost around 500ft...

I guess it's fortunate that this happened relatively in range of the airfield. Scary stuff!

[BA747-436]

Fortunate? Id say that's about the biggest understatement you could muster up lol.

Also any idea what that huge hole is from near the wing root on the wing? My initial guess would be landing gear strut being rammed up through the wing on landing? Or possibly something to do with the engine disintegrating.

[Calfo]

[photoid=6152406]
[photoid=6152404]

[Chris Kilroy]

Also any idea what that huge hole is from near the wing root on the wing? My initial guess would be landing gear strut being rammed up through the wing on landing? Or possibly something to do with the engine disintegrating.

I'd say it was the gear strut puncturing the wing. Reports (and yes, I know how inaccurate those can be) all seem to indicate that the aircraft crossed the fence at an extraordinary high angle of attack, with the wings rocking back and forth. That's pretty indicative of being on the edge of a stall, which would be expected in this case. If both engines did indeed fail, it wouldn't take but a few seconds for all the drag from those huge flaps to take hold and decay the airspeed significantly.

In that situation, you'd want to lower the nose to maintain whatever airspeed you had left, and aim for a touchdown (stall) just beyond the last major obstacle you'd really want to clear (in the case of a 27L approach, likely the perimeter road). If that's what the crew were trying to do (pure speculation on my part), they pulled it off as well as could be expected.

The condition of the gear, and the fact that the aircraft stopped about 900ft from where it touched down, indicates that they touched down extremely hard, and had hardly any energy left when they did so. Thus my speculation that the hole in the wing is from the gear strut coming through.

[BA747-436]

Id say your explanation sounds just about spot on. The high angle of attack coupled with the presumably low airspeed would be enough to do this damage and stop the plane relatively quickly. Perhaps if it had been able to make it to the runway (which may have not been such a good idea...) the aftermath would not have been so pretty? Asphelt coupled with a large impact of a metal structure and aviation fuel can be a messy concoction. . . So in this case landing on relativly soft grass area ahead of the runway could have been a contributing factor to the positive outcome of this mishap. I have to say that its also becomming apparant that the crew pulled off a minor miracle getting her down in one piece (or near enough) and with minimal casualties. Of course, what caused the total power outage will be interesting to discover and divulge. One must be thank full that this wasn't an aircraft made from a mostly composite material like those made by a competing company or the outcome of the condition of the aircraft on completion of its emergency landing may have been somewhat different .... Purely speculation on my behalf though ;-)

[turbotraker]

As more and more info trickles through, its pretty obvious the passengers have been extreemly lucky, this could have been much worse.

On a related note, can anyone help me work this comment out??:

http://news.sky.com/skynews/picture_gallery/picture_gallery/0,,70131-1301172-16,00.html

[BA747-436]

My first guess would be someone who has no idea what they are talking about. So basically anyone from a news station...

My other guess would be someone with no clue about aviation trying to describe a 777 stalling.

[turbotraker]

Cannot remember where (probably sky/bbc), I read that this jet 'may' have run out of fuel. Is that possible these days?

I am not an expert but surely filght crew calculate weight/distance and take on enough fuel to cover plus a some spare. But can an aircraft actually run out of fuel??

Murt

[FlyingPhotog]

Cannot remember where (probably sky/bbc), I read that this jet 'may' have run out of fuel. Is that possible these days?

I am not an expert but surely filght crew calculate weight/distance and take on enough fuel to cover plus a some spare. But can an aircraft actually run out of fuel??

Murt

Of course it's physically possible to run out of fuel. But you would receive warnings indicating a fuel shortage before hand. Aircraft are only filled with a finite amount of fuel, and once you run out you become a glider.

However I am not suggesting that's what happened in this case.

[BA747-436]

I would be very surprised if it ran out of fuel. Although its a long flight from Beijing there should be a fair bit of fuel left for any sort of pattern hold that is required or a divert. If there was any hint of a fuel issue than I'm sure they would have put the aircraft down somewhere over northern Europe rather than 'wing it' (excuse the pun!) and try and get her home.

[AA 1818]

And the positive aspects to this incident:

This showed the greatness of the crew. Had it not been for an experienced, well-trained crew, many of us would be offering our condolensces.

This also showed the greatness of the 777 - considering that this will be the first, hull-loss incident involving the type in it's majestic (and when considered - long) history!

[Chris Kilroy]

Begin Speculation Again --

I'd be surprised if landing on grass vs. landing on a concrete surface even entered the crew's mind. Basically, in a low energy power loss situation, you aim for the first suitable landing spot which, in this case, happened to be grass. Trying to "stretch" your glide in this sort of scenario, when not absolutely necessary, is taking a hell of a risk. You use the energy you've got to get to the closest safe landing spot, and not an inch further. Had the crew tried to make the runway, they could have easily lost just a bit more airspeed/intertia, and planted it into those row houses just prior to the perimeter road.

I'm sure, under ideal circumstances, the flight crew would have preferred to make the runway. Setting it down on concrete (in a controlled manner) has far less possible consequences than planting it in the grass, ripping off the gear, and careening through approach lights, signage, and other FOD on your way to a stop.

In the end, the crew made the correct decision -- sure, they broke the airplane, but nobody died, or was even seriously injured, and that's what is ultimately most important.

[G-DALE]

Cannot remember where (probably sky/bbc), I read that this jet 'may' have run out of fuel. Is that possible these days?

I am not an expert but surely filght crew calculate weight/distance and take on enough fuel to cover plus a some spare. But can an aircraft actually run out of fuel??

Murt
Of course an aircraft can run out of fuel. It's just like running out of fuel in your car, except it's obviously not just a case of 'pulling over' at the side of the road.

However It's been confirmed that there was enough fuel in the tanks for flight 038 to land safely so fuel starvation wasn't an issue.

Dale

[JordanD]

I'm not speculating or anything, but what 777 engines were supposedly having reliability issues? I remember there was the Malaysian 777 that shed some engine parts on takeoff about a year ago, and I believe there was a BA 777 with engine problems over the U.S. a few years back.

[Crism]

I'm not speculating or anything, but what 777 engines were supposedly having reliability issues? I remember there was the Malaysian 777 that shed some engine parts on takeoff about a year ago, and I believe there was a BA 777 with engine problems over the U.S. a few years back.

Bilo hit the button again....DAMNNIT!

[brianw999]

.....they could have easily lost just a bit more airspeed/intertia, and planted it into those row houses just prior to the perimeter road.
I was thinking about that. Can you imagine being a Myrtle Avenue resident and looking out of your back window to see that.

....and now we await the tree-hugging, airports aren't safe, global warming crowd.

[CcrlR]

Of course it's physically possible to run out of fuel. But you would receive warnings indicating a fuel shortage before hand. Aircraft are only filled with a finite amount of fuel, and once you run out you become a glider.

However I am not suggesting that's what happened in this case.

Whenever you are flying, you have to have a reserve amount usually this is in the form of munites Usually 45 minutes for a diversion to another airport or for circling around waiting if it is ok to land. Luckily it landed within the airport boundary and no one was killed. Someone told us about this in my Aircraft Accident Investigation class. Luckily that this did not end up crashing into the houses nearby.

[Crunk415balla]

If they ran out of fuel, I'm sure the pilots would have reported that they were low on fuel when the alarms went off.

Who knows what caused it at this point, but they managed to claw to the air long enough to clear the last deadly obsticle, and they should be commended for it.

[FlyingPhotog]

....and now we await the tree-hugging, airports aren't safe, global warming crowd.

"I hate the noise, the traffic, and the possible cancer I might get from jet exhaust. But I will continue to live here because it's a "good location."

Signed,

Typical NIMBY


Thats like those idiots who build homes in California in the valley between hills. Then they are shocked when there's a mud slide. :roll:

/off my soap box 8)

[turbotraker]

I would be very surprised if it ran out of fuel. Although its a long flight from Beijing there should be a fair bit of fuel left for any sort of pattern hold that is required or a divert. If there was any hint of a fuel issue than I'm sure they would have put the aircraft down somewhere over northern Europe rather than 'wing it' (excuse the pun!) and try and get her home.

I guess most aircraft carry enough in case of emergencies. But after having a quick look have found that some airlines do/have/are taking the chance:

Below is an article from the Independent Newspaper quite an old quote (10 years).

AIRCRAFT REGULARLY fly over London carrying too little fuel to cope with diversion or an emergency, an authority on aircraft safety said yesterday.

The claim followed the revelation that a Malaysian jumbo jet had arrived at Heathrow with so little fuel that even a slight delay could have meant that it crashed over London.

The following from USAtoday (a more recent quote), this was relating to a British Airways 747 that lost power to one of its engines.

The pilot made an emergency landing in Manchester, England, about 160 miles short of London, because the Boeing 747 ran low on fuel after facing headwinds that were stronger than expected, the Federal Aviation Administration said.

[Dan380]

But as mentioned before, the pilots would know if the fuel was low, and they would alert ATC to the problem.

Another person on another forum suggested windshear. I'm no expert on aircraft electronics but I believe the suggestion was that it had confused the flight computers somehow. I can't quite see how wind could cause this, but the wind down here today has been very strong. So if it is indeed possible, then we certainly have the right circumustances for this to occur.

My experience from watching Air Crash Investigation programs is that these crahses are never the result of one mistake/fault/error. There is allways a sequence of events and so I don't think we can rule out any theories just because they are not possible under normal conditions.

[AASuper80Fan]

I'd like to congraulate the crew for getting the plane down considering the cirumstances from what we know, I hope get the recognition they deserve.

[Jerrycobra Boeing]

wow, that doesn't look too good, good thing everyone survived, though, the 777 no longer has a clean hull loss record, but as long as everyone lived, its good!

[AA 1818]

The pilot made an emergency landing in Manchester, England, about 160 miles short of London, because the Boeing 747 ran low on fuel after facing headwinds that were stronger than expected, the Federal Aviation Administration said.

IIRC, this was the incident that occured in Feb. 2005 - in which the aircraft damaged the engine upon takeoff from LAX, however - the crew decided to continue to the U.K. in order to avoid incurring huge fines (due to EU stipulations for delays and the like). The response (to the incident) was most interesting in that there was a disagreement between the FAA and UK authorities over whether the captain took the correct coruse of action. According to UK, and BA standards - it was acceptable to fly with 3 engines (and not be able to achieve their reccomended cruising altitude - which equated to greater feul burn).

[ollieholmes]

I hate threads like this, i have been trying to avoid it since i herd the news this afternoon. I wish people would not speculate on what happened or what could have happened. That is for the Uk AAIB to discover and when they publish their report we can all find out as it will be on their website. If you dont know the web adress here it is:
www.aaib.gov.uk (http://www.aaib.gov.uk)
We should all be very greatfull that the crew executed a safe emergancy landing and everyone got out safe. The effect if the aircraft had landed short even by a small distance does not bear worth thinking about.

[Cam]

^I agree Ollie!

ad.com had a good thread on it.....Chris, the site down?


From what we've heard, there was a power failure, so it will be a waiting game until the investigation is done.

[Calfo]

[photoid=6152712]
[photoid=6152505]
[photoid=6152482]
[photoid=6152475]
[photoid=6152458]

[hansonator69]

Thank God everyone survived. The pilot's skills saved lives. Could this be the first written-off 777?

[Will M]

<object width="425" height="355"><param name="movie" value="http://www.youtube.com/v/CYwQ4EHQY8Y&rel=1"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/CYwQ4EHQY8Y&rel=1" type="application/x-shockwave-flash" wmode="transparent" width="425" height="355"></embed></object>

here a vid of the landing. Such a high AoA ! Almost A330 style ;)

[Arrow]

^I agree Ollie!

ad.com had a good thread on it.....Chris, the site down?

AD.Com forums gone bye-bye forthwith. This notice is up

"Dear AirDisaster.Com Forum members,

At about 3pm U.S. Pacific Time today, the web server that hosted the AirDisaster.Com forums suffered a catastrophic failure which rendered both
hard drives useless and irrecoverable. Unfortunately, one drive in this server contained the live forums database, and the other contained the daily
database backups.

With this in mind, I'm sorry to report that, effective immediately, the AirDisaster.Com Discussion Forums are closed permanently. These forums were
home to hundreds of thousands of posts, and to attempt to start from scratch at this point would be futile, in my opinion.

For those of you looking for a place to continue discussing aviation safety, we have introduced a new Aviation Safety Discussion Forum (http://forumdisplay.php?f=29) at our sister site,
JetPhotos.Net. While I know this isn't the ideal solution for many of you, I would still invite all of you to visit the JP.Net forums, sign up, and
participate!

On a personal note, to me, this is the end of an era. These forums were regarded as the most authoritative aviation safety forums on the internet,
for a period of almost 10 years. On top of that, they were home to many friendships, some rivalries, and spawned at least one successful marriage.
That, above all else, will be the legacy of these forums long after they're gone.

I'd like to thank each and every one of you who helped to make the forums as successful as they were, and would like to thank, especially, the
administrators, moderators, and industry forum hosts who devoted their free time to make this place the best it could possibly be.

I guess that's about it. I hope to see many of you over at the JetPhotos.Net forums, and to those of you who will no longer participate, the best to all of you for a bright and prosperous future.

Last one out, hit the lights!

Chris Kilroy
Editor, AirDisaster.Com

[Star Alliance]

Last one out, hit the lights!

Chris Kilroy
Editor, AirDisaster.Com
Oh my goodness! It feels like the day TWA died all over again (and I didn't even participate in those forums...).
:( End of an era, boys. End of an era.

[JordanD]

Wow. Was somebody just randomly filming the landing or something? Would they have been trying to stretch their glide to make sure they cleared the houses/highway? (That's quite a high angle of attack it seems like)

[AJ]

What a terrible predicament.

One thing does stand out to me though......the APU door is open. This would normally only be the case if an low-vis autoland was being conducted (unlikely in the conditions), after an engine failure or an IDG failure. This is not in itself completely out of place as in the event of a dual engine failure an APU start is attempted, although not until after trying to relight the engines via FLT on the ignition etc etc.

Has there been any suggestion that one engine had already been shutdown earlier in the flight? Memories of Kegworth which unfortunately did not have a large grass area.

[AJ]

....wow, just learnt something about the 777. After the loss of power to both engines the APU will attempt an autostart! What an amazing aircraft.

[Tbun]

That video in the post a few above... Am I right in thinking it has been cut short because of the investigation?

If so why would they do that? To what end?

[fly4bux]

I'm wondering why the RAT isn't out in the video..with the reports of the engines out and the electrical busses not powered....looks like we can't count on the RAT!

[aardvark2zz]

Page 6 of 6


Unread Today, 04:51 PM #201
Half Bottle
Forum Attention Whore

Half Bottle's Avatar

Join Date: May 2005
Posts: 8,034

Default
From cnn.com....

Quote:
Jerome Ensinck, a passenger aboard the flight, said there had been no indication that the plane was making an emergency landing.

"There was no indication that we were going to have a bad landing," he said. "When we hit the ground it was extremely rough, but I've had rough landings before and I thought 'This is the roughest I've had.'

"I feel lucky at the moment, but I think now I realize I've had a close call. If we had hit the runway, it would have been worse."

Note to Mr. Ensinck: hitting the runway is normally the preferred method for landing.
Half Bottle is offline Report Bad Post Reply With Quote
Half Bottle
View Public Profile
Send a private message to Half Bottle
Find More Posts by Half Bottle
Add Half Bottle to Your Buddy List
Unread Today, 04:53 PM #202
reubee
Senior Member

reubee's Avatar

Join Date: Oct 2004
Location: AKL
Posts: 576

Default
Quote:
Originally Posted by ToRX
No it's not:



I stand corrected, thanks
reubee is offline Report Bad Post Reply With Quote
reubee
View Public Profile
Send a private message to reubee
Find More Posts by reubee
Add reubee to Your Buddy List
Unread Today, 04:57 PM #203
FreedomOfSpeech
Junior Member

Join Date: Sep 2007
Posts: 15

Default
Quote:
Originally Posted by Walter Sobchak
Wouldn't any holds be irrelevant once a fuel emergency is declared? I always thought ATC would give maximum priority to an aircraft running out of fuel. Also, the major London airports aside, there are tons of other runways long enough for a 777 in that area.


Yes but the point is that no one wants to declare a fuel emergency because that is serious shit and there is an investigation afterwards as to how the plane got in to that situation.

Normally running low on fuel happens transatlantic or other long haul due to the Jetstream not running how you expect etc, etc or may be losing an engine on the way. So typically a plane would divert much earlier on a long haul flight rather than divert to Gatwick. But flying say Manchester or Edinburgh to Heathrow presumably a Gatwick diversion due to a fuel screw up and then exceptionally long predicted hold as you near Heathrow approach is entirely likely.

Planes land at Shannon etc regulalry because they think they might not have enough fuel for Heathrow. No near accident miss investigation is required as the airline merely incurs extra cost but the pilot is behaving prudently and responsibly. The only enquiry may be an internal one by the airline because the flight is made seriously late, an outbound departure is lost (and may be also the return from that departure) and extra landing fees are paid. That is the problem of the airline and its passengers commercially and in reputation terms but it is not the CAA or the AAIB's problem.

Of course some pilots fear the crap of the internal enquiry more and/or are badly trained and lacking in intelligence and common sense and hence we end up with an Aeromexico type situation.
FreedomOfSpeech is online now Report Bad Post Reply With Quote
FreedomOfSpeech
View Public Profile
Send a private message to FreedomOfSpeech
Send email to FreedomOfSpeech
Find More Posts by FreedomOfSpeech
Add FreedomOfSpeech to Your Buddy List
Unread Today, 04:59 PM #204
ils26
Junior Member

Join Date: Aug 2006
Location: Stockholm, Sweden
Posts: 3

Default
Quote:
Originally Posted by V2500
Btw, bet that hole in the fuselage came from when that loose boogie comming off and tumbling away.


I'm beginning to believe that too (you can see the gear's position in relation to the hole in the photo http://www.airliners.net/open.file/1318204/M/ ).

The people sitting in the rows above that hole are really lucky. The gear could just as well had hit - and entered - their windows, injuring or killing them.
ils26 is offline Report Bad Post Reply With Quote
ils26
View Public Profile
Send a private message to ils26
Send email to ils26
Find More Posts by ils26
Add ils26 to Your Buddy List
Unread Today, 05:00 PM #205
Dmmoore
Super Moderator

Dmmoore's Avatar

Join Date: Nov 2001
Location: N01.21.080' E103.58.306' or N34.36.53 W112.27.44
Posts: 6,421

Default
Quote:
Originally Posted by procede
Could the FMC/pilots have selected empty fuel tanks as they where approaching the airfield? for example they could have drained the inner tanks, switched to the outer and gone back to direct feed during approach...

Anything is possible but that would require manual control of the fuel system. The FSC will not allow that scenario.
Dmmoore is online now Report Bad Post Reply With Quote
Dmmoore
View Public Profile
Send a private message to Dmmoore
Find More Posts by Dmmoore
Add Dmmoore to Your Buddy List
Unread Today, 05:02 PM #206
obmot
Senior Member

Join Date: Feb 2002
Location: Manhattan
Posts: 145

Default
Quote:
Originally Posted by reubee
I stand corrected, thanks


If I had to guess, the wheels laying there on the lawn is part of the right rear main bogie because I can see the front wheels and what appears to be a set of 3 wheels on the left (looking at the pic above looking at the front of the aircraft).
obmot is offline Report Bad Post Reply With Quote
obmot
View Public Profile
Send a private message to obmot
Find More Posts by obmot
Add obmot to Your Buddy List
Unread Today, 05:02 PM #207
Dmmoore
Super Moderator

Dmmoore's Avatar

Join Date: Nov 2001
Location: N01.21.080' E103.58.306' or N34.36.53 W112.27.44
Posts: 6,421

Default
Quote:
Originally Posted by mawheatley
I'm sorry - what is the significance of the APU intake being open?

It indicates the APU was running, or was in the start-up cycle.
Dmmoore is online now Report Bad Post Reply With Quote
Dmmoore
View Public Profile
Send a private message to Dmmoore
Find More Posts by Dmmoore
Add Dmmoore to Your Buddy List
Unread Today, 05:06 PM #208
Half Bottle
Forum Attention Whore

Half Bottle's Avatar

Join Date: May 2005
Posts: 8,034

Default
Ok, just to throw something out there that is almost certainly unrelated, but may be fun to chew on while we await facts. Does anyone know what the outcome was of the investigation into the Malaysian 777 that had, for lack of a better term, an avionics 'gremlin' a few years back?

http://www.airdisaster.com/forums/s...ead.php?t=75655
Half Bottle is offline Report Bad Post Reply With Quote
Half Bottle
View Public Profile
Send a private message to Half Bottle
Find More Posts by Half Bottle
Add Half Bottle to Your Buddy List
Unread Today, 05:12 PM #209
andytoop
Senior Member

Join Date: Jul 2002
Location: London
Posts: 640

Default
Quote:
Originally Posted by FreedomOfSpeech
I may not have a pilot's licence but as a frequent air passenger in to all five commercial London airports I do know enough about holding times and approach patterns to know you are talking unmitigated claptrap here.
I regularly talk unmitigated claptrap - but I think you missed the point.
I wasn't sugesting that the holding patern for Gatwick is the same as the one for Heathrow. I was talking about a plane already in the Heathrow pattern with Heathrow as its destination and Gatwick as its alternate. (Actually I was particalry thinking of the biggin stack
Also a stright divert, not for a fuel emergency. If the plane diverted to Gatwick it would still have to hold to get a slot on the runway. If its going to declare a fuel emergency to get into Gatwick, it may as well do so to get into Heathrow. If they declare an emergency they wont be in the hold for twenty minutes they will jump to the front of the queue.
andytoop is online now Report Bad Post Reply With Quote
andytoop
View Public Profile
Send a private message to andytoop
Find More Posts by andytoop
Add andytoop to Your Buddy List
Unread Today, 05:20 PM #210
aardvark2zz
Senior Member

aardvark2zz's Avatar

Join Date: Jan 2002
Location: Not Here
Posts: 1,779

Default
OK I want you to stop and think about your statement.

Quote:
Originally Posted by IntheShade
OK I want you to stop and think about your statement.

If I am flying an airplane and drop down to battery power yet still have the battery powered backup flight instruments the last thing I want to do is attempt a APU start and totally drain the battery because "You know you can't rule out two generator or gcu problems which would let the apu come on line since the fault(s) would be south of the line contactors."

I'm going to stick with what I have and not risk losing it all. .....

You`re forgetting the APU battery !

.
aardvark2zz is online now Edit/Delete Message Reply With Quote
aardvark2zz
View Public Profile
Send a private message to aardvark2zz
Find More Posts by aardvark2zz
Add aardvark2zz to Your Buddy List
Unread Today, 05:22 PM #211
FreedomOfSpeech
Junior Member

Join Date: Sep 2007
Posts: 15

Default
Quote:
Originally Posted by andytoop
If the plane diverted to Gatwick it would still have to hold to get a slot on the runway. If its going to declare a fuel emergency to get into Gatwick, it may as well do so to get into Heathrow. If they declare an emergency they wont be in the hold for twenty minutes they will jump to the front of the queue.


And my point was that a pilot getting low on fuel hearing there was a 15 or 20 minute hold pattern at Heathrow before entering the holding pattern would see if he could divert to Stansted, Luton or Gatwick if he was told there was currently near no holding time to land there and near immediate landing on approach.

He then lands without declaring a fuel emergency and avoids a problem with the air regulation authorities but undoubtedly possibly (depending on who or what is at fault in causing the low fuel situation) gets in to one with the commercial management of his airline (especially if it is Ryanair). Therein lies the pilot dilemma and the reasons some pilots take chances instead of playing safe.

Also I would presume that when planes are stacked at Heathrow and there is a serious ncident on the landing runway in use, such as a plane with locked brakes on the runway, that means Heathrow has to go to single alternating land/depart runway operation that large numbers of planes in the stack then divert to airports including Gatwick so they can safely land on their remaining available fuel. This is because in those circumstances the stacking time is probably going to more than double for Heathrow.
FreedomOfSpeech is online now Report Bad Post Reply With Quote
FreedomOfSpeech
View Public Profile
Send a private message to FreedomOfSpeech
Send email to FreedomOfSpeech
Find More Posts by FreedomOfSpeech
Add FreedomOfSpeech to Your Buddy List
Unread Today, 05:30 PM #212
aardvark2zz
Senior Member

aardvark2zz's Avatar

Join Date: Jan 2002
Location: Not Here
Posts: 1,779

Default
Quote:
PPRuNe Message We are sorry but The Professional Pilots RUmour NEtwork is temporarily closed while we perform some essential maintenance on the website. Due to the extremely high number of visitors, the servers are unable to cope with the demands. We are doing everything we can to rectify this situation. Normal service will resume shortly and we thank you for your patience.


As I posted this, even AD.com hung !!

.

[pbateson]

That is terrible.

2nd crash in 2008 with no fatalites?

May be 1st B777 W/O?

The wings were very bad damage over the torn landing gears.

[aardvark2zz]

Oh my goodness! It feels like the day TWA died all over again (and I didn't even participate in those forums...).
:( End of an era, boys. End of an era.

Could happen here too. All those posts, all those pics; all of a sudden POOOUFFFF forever .....

.

[BA747-436]

Actually we have a few fail safe devices to stop something like that happening. :-)

[MaxPower]

That is terrible.
2nd crash in 2008 with no fatalites?
May be 1st B777 W/O?
The wings were very bad damage over the torn landing gears.Make that two crash too many, regardless of the non fatality, the first month isnt even over yet, with this rate of incidents, I mean if it continues this way this is not looking good, Happy wings, guys !

[afkabruce98]

Hey, the BBC just contacted me asking to use this shot in their 6 o'clock bulletin.
http://jetphotos.net/viewphoto.php?id=6136618&nseq=9
I'm supposed to get on screen name credit, so if any of you UK guys see it, would you kindly let me know if they kept their word (seeing they are using the image for free!).
Cheers.

[BA747-436]

You tool Seth, there's money to be made there. lol

Ill keep an eye out.

[afkabruce98]

Well, unfortunately those stingy poms wouldn't part with any $$. So I thought a little publicity is better than nothing.

[BA747-436]

Dam tight ass news agency's. Well yeah I guess your right publicity is better than a kick in the teeth. At least you can now put BBC down on your client list ;-)

[Half Bottle]

So, any news this morning on the actual, you know, plane crash?


Anyone who knows me knows how I despise all this off-topic thread creep in safety fora.

[HalcyonDays]

Some interesting new pictures....:

http://www.heathrowpictures.com/pictures/pictures.html

Picture in the fourth row, second one in : what is the hole ?

Also, maybe an AAIB interim statement due within 48 hours of the crash, ie. maybe tomorrow :

http://www.aaib.dft.gov.uk/latest_news/accident__heathrow_17_january_2008.cfm

[Dmmoore]

Has there been any information released indicating any reason for both engines to flame out?

The last I heard, the pilots report power loss as 500 feet. The PAX reported normal cabin lighting until touchdown but at 1 PM they may not have noticed.

Don
Refugee from ADC

[Dmmoore]

Some interesting new pictures....:

http://www.heathrowpictures.com/pictures/pictures.html

Picture in the fourth row, second one in : what is the hole ?

Also, maybe an AAIB interim statement due within 48 hours of the crash, ie. maybe tomorrow :

http://www.aaib.dft.gov.uk/latest_news/accident__heathrow_17_january_2008.cfm

Excellent photo's!
The pictures showing the engine intakes indicate both engines were not producing power when they were stopped by damage. However after touch down, the pilots would have retarded the engines to idle.

Don
Refugee from ADC

[Shaggy]

Something else that impresses me that we take for granted are the actions of ATC. those boy and girls must have been working their butts off for a while, especially at the point of the accident.

Well done ATC

[Half Bottle]

Some interesting new pictures....:

http://www.heathrowpictures.com/pictures/pictures.html

Picture in the fourth row, second one in : what is the hole ?


I think it's where the departing main gear impacted the fuselage.

[BA747-436]

Yeah struts from the main gear would have punctured the wing near the root on touchdown at that velocity.
From what I hear the APU ran an auto-startup as the engines both failed, this would give the impression of normal lighting in the cabin although there would have been at least a flicker as the power transition was handed over. Possibly not something anyone would have noticed in daylight though.

[fly4bux]

The 777 APU takes almost a full minute to spool up after a start command. When the engines quit, it shoulda got dark inside, except for the emergency isle lighting. The RAT, should have deployed to provide essential electrics and degraded flight control hydraulics. However, I don't see the RAT deployed in the landing video. (it's BIG!)

With an emergency declared at 500' or less, ATC didn't have time to do anything, other than interrupt a tense situation with..."Say fuel status and Souls on Board...state intentions" and whamo, you've got a bent 777 on your front porch.

[Half Bottle]

With an emergency declared at 500' or less, ATC didn't have time to do anything, other than interrupt a tense situation with..."Say fuel status and Souls on Board...state intentions" and whamo, you've got a bent 777 on your front porch.
Did they declare an emergency? Or are you just speaking hypothetically?

[fly4bux]

NBC reported an emergency declared **prior** to the incident, which in the short hairs was outstanding work by the crew, as it probably got the ARF rolling by the time the first slide popped. (Hopefully)

CNN reports dual engine failure at less than 500' so, between dead stickin'er in and declaring an emergency, a top notch, no notice evac by the cabin crew, I would say they all go into the hall of heroes.

[VA-viking]

Love the way press & people laude the pilots for saving everyone's life, when statistically the crash was most likely caused by pilot error !
bit like driving a bus drunk and then being praised after a crash because no one was hurt...

[fly4bux]

I don't understand your metaphor of a drunk bus driver vs dual engine flame out at 400'.

[Half Bottle]

I don't understand your metaphor of a drunk bus driver vs dual engine flame out at 400'.I think he's saying that, statistically speaking, it is probable that the pilots did something that caused the flameout. While he may be correct from a pure numbers game, I wouldn't be so quick to jump to that conclusion in this specific accident. The bottom line, of course, is that we have no idea whether the pilots will turn out to have done a good job or a poor one.

[T.O.G.A.]

Has it been determined whether or not there was fuel around the crashsite?

Looks like the gear ripped through the tanks.

[Schorsch]

I think he's saying that, statistically speaking, it is probable that the pilots did something that caused the flameout. While he may be correct from a pure numbers game, I wouldn't be so quick to jump to that conclusion in this specific accident. The bottom line, of course, is that we have no idea whether the pilots will turn out to have done a good job or a poor one.

Halfie,

a good landing is one you can walk away from. An excellent landing is one after which you can use the aircraft again. In conclusion, the pilots did a good job, but not an excellent.

Fuck, that was my first post. And no serious engineering involved ...

[Dmmoore]

I don't understand your metaphor of a drunk bus driver vs dual engine flame out at 400'.

I applaud the crew for getting the big bird on the ground safely. However until the cause of a double engine failure is discovered, I will with hold my final pronouncement.

It's one thing to save an airplane, it's another to have put the airplane in danger by your previous actions, then save your ass.

[Chris Kilroy]

Has it been determined whether or not there was fuel around the crashsite? Looks like the gear ripped through the tanks.

The 777 has both wing and center (body) tanks although, in the landing phase, you'd expect much more fuel to be in the wings than in the center tanks. Reports yesterday were that there was 'sufficient' fuel still in the aircraft when it crashed.

[Dmmoore]

Has it been determined whether or not there was fuel around the crashsite?

Looks like the gear ripped through the tanks.

It appears the damage caused by the overload on the gear is aft of the wing box and the tanks are relatively intact.

Small leaks from sheared bolt's are possible but I don't "think" the tanks were ruptured.

[control_freq]

The video is pretty grainy. I think the RAT could have been deployed - it's tiny compared to the landing gear, as seen in this photo: http://www.airliners.net/open.file/971431/L/

[Dmmoore]

The 777 has both wing and center (body) tanks although, in the landing phase, you'd expect much more fuel to be in the wings than in the center tanks. Reports yesterday were that there was 'sufficient' fuel still in the aircraft when it crashed.

Thanks Chris, I had not seen that report.
All (except trapped, unusable) fuel should be in the wing tanks. If not, there is a FSC error with notification to the crew.

By the way,
Another nice site.
Thanks!

[Arrow]

The bottom line, of course, is that we have no idea whether the pilots will turn out to have done a good job or a poor one.


Witness the initial response to either Air Transat 236 or the Gimli Glider

[~InsertNameHere~]

ooo http://news.bbc.co.uk now!

they're just about to have a live interview with the captain...

[T.O.G.A.]

It appears the damage caused by the overload on the gear is aft of the wing box and the tanks are relatively intact.

Small leaks from sheared bolt's are possible but I don't "think" the tanks were ruptured.

Maybe the box wasn't ruptured but the photo from left rear wing shows a pretty warped rear spar. There is always residual fuel in the wing tanks.

Even if it was limited to a small leak, I would expect to see some effort to protect the environment from a (potential) fuel spill but I havn't yet.

So if it wasn't a fuel issue, could it have been a commanded shutdown ala Delta out of LAX or a massive "fly by wire" failure?

[pelican98]

Hi, everyone, can anyone tell from the gear tracks what was the angle of attack at the moment of impact, it looks like he brought the nose down considerably after clearing the fence compare to the high aoa on the existing video.

[sjwk]

A British Airways jet that crash-landed at Heathrow was being controlled by the co-pilot, it has been revealed.
Captain Peter Burkill told a press conference Senior First Officer John Coward brought the plane in to land on Thursday afternoon.

"As British Airways flight and cabin crew we are trained on a regular basis to deal with emergency situations," he said.
"We have procedures to follow and everyone knows their place.
"Flying is about teamwork and we had an outstanding team on board."
He said Mr Coward had done a "most remarkable job" in landing the aircraft.

It doesn't say what the captain was doing though, if not flying the plane - which I'd have expected to be 'his place'?

Would it be normal in that situation for the co-pilot to land the plane or would that normally be the job of the most experienced pilot?

Steve.

[uy707]

More

DATE:17/01/08
SOURCE:Flightglobal.com
VIDEO & GRAPHIC: Flight's safety editor David Learmount gives his account of what happened to the BA Boeing 777 that crash landed at Heathrow
By Barbara Cockburn

Flightglobal.com's safety and operations editor David Learmount gives his views on what he describes as a "remarkable" accident at London's Heathrow airport on 17 January.

Learmount says: "The aircraft had either a total or severe power loss and this occurred very late in the final approach because the pilot did not have time to tell air traffic control or passengers."





He says that it was "quite a remarkable accident" and unlike any he has seen before.

He says: "The pilot had no choice but to heave the aircraft over the boundary fence and put it down."



--------------------------------------------------------------------------------


This graphic shows what happened to the aircraft as the pilot put the aircraft down




--------------------------------------------------------------------------------


Related content:

BREAKING NEWS: BA 777 severely damaged in Heathrow landing accident
Aircraft profile - Boeing 777
Have your say about the incident on AirSpace
Pictures of the incident

Close-up pictures, if not a writt-off, looks she will be unavialable for months.
http://www.flightglobal.com/articles/2008/01/18/220935/pictures-ba-boeing-777-heathrow-crash-evidence.html
Some opinions
http://www.flightglobal.com/articles/2008/01/18/220942/what-pilots-are-saying-about-the-ba-777-accident.html

[Half Bottle]

It doesn't say what the captain was doing though, if not flying the plane - which I'd have expected to be 'his place'?

Would it be normal in that situation for the co-pilot to land the plane or would that normally be the job of the most experienced pilot?

Steve.
If the F/O is flying the leg, I would expect the Captain to let him land it unless the former was doing something so dangerous that he had no choice. In fact, in many emergency situations, the Captain may do the reverse: hand the flying duties over to the F/O so he can manage the emergency. That's where the Captain's experience is most needed.

(Again, neither was likely in this case if the emergency really developed on very short final).

This talking from the parlour brought to you by the letter B and the number 3.

[Vnav]

Something else that impresses me that we take for granted are the actions of ATC. those boy and girls must have been working their butts off for a while, especially at the point of the accident.

Well done ATC

You're kidding right?

Nothing against the fine ATC folks, but what exactly do you think they did for a crew that had a dual engine flameout on short final aside from offering..."Good Luck, we're all counting on you!"

[sickbag]

How are they going to move it now it hasn't got any wheels?

[sjwk]

How are they going to move it now it hasn't got any wheels?
They'll declare it a wreck, and hordes of Devon-folk will appear and cart it away, piece by piece...

Link, for non-locals :) (http://news.bbc.co.uk/1/hi/magazine/7194289.stm)

Steve.

[brianw999]

How are they going to move it now it hasn't got any wheels?
<!-- / message -->

Most likely in two or three pieces on lowloaders. Get ready for a huge traffic jam on the M25 and M3 as the convoy wends its way to Farnborough or wherever the bits will eventually be taken to..

[sickbag]

Is it a write off?

Do they cut it up or unbolt it?

[HalcyonDays]

<!-- / message -->

Most likely in two or three pieces on lowloaders. Get ready for a huge traffic jam on the M25 and M3 as the convoy wends its way to Farnborough or wherever the bits will eventually be taken to..

I'm assuming it's still there as of now - and thus causing much disruption, unless 27L can be used for shortened take-offs from an intersection point, which should be possible for short/medium hauls.

I assume the decision to declare a hull loss or not, which will depend on discussion between the owner and the insurance chain (reinsurers involved too), is yet to be made but must be urgent. But even more urgent is the operational need to move the wreckage. If it can be cut up, that will ease matters. Otherwise, I would imagine a move to one of the nearby hangars. At least it was fortuitous from that viewpoint that it didn't finish up at the other end of the field.

[scottkin]

According to the report I just watched on BBC. The F.O. was flying the plane. And yes there was an emergency declared. Im a AD.com refugee 1st time poster. Seems like a nice site you have here.

[uy707]

Welcome on board our asylum and enjoy your status of JP.net resident.

[Half Bottle]

According to the report I just watched on BBC. The F.O. was flying the plane. And yes there was an emergency declared. Im a AD.com refugee 1st time poster. Seems like a nice site you have here.
Scott, did the BBC report confirm that the emergency was declared on short final (as opposed to some fuel emergency a minute or two beforehand, for example).

[Tbun]

That video in the post a few pages back... Am I right in thinking it has been cut short because of the investigation?

If so why would they do that? To what end?

[Half Bottle]

From BBC Online (http://news.bbc.co.uk/2/hi/uk_news/england/london/7196526.stm)...

[Captain] Burkill and [First Officer] Coward are said to have shared a curry on Thursday night after the incident.

[scottkin]

According to the BBC report, it said distress call on short final. Nothing mentioned about possible fuel starvation. I have a friend thats an air marshall that was at Heathrow yesterday. And according to 2 people he talked to that witnessed the accident, They didnt notice anything unusual until just before they crossed the outer perimeter and then noticed the left wing drop sharply at approximately two hundred feet and the plane pancaked. And thanks for the welcome uy707:wink:.

[juan23]

Peliminary AAIB report...

<TABLE cellSpacing=0 cellPadding=0 width=760 border=0><TBODY><TR><TD width=10></TD><TD vAlign=top width=629><TABLE cellSpacing=0 cellPadding=0 width=629 border=0><TBODY><TR><TD vAlign=top width=629>Last Updated: Friday, 18 January 2008, 17:57 GMT http://newsimg.bbc.co.uk/shared/img/o.gif http://newsimg.bbc.co.uk/nol/shared/img/v3/dot_629.gif
<TABLE cellSpacing=0 cellPadding=0 width=416 border=0><TBODY><TR><TD width=213></TD><TD width=203></TD></TR></TBODY></TABLE>
</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=0 width=629 border=0><TBODY><TR><TD colSpan=3>In full: AAIB initial statement

</TD></TR><TR><TD vAlign=top width=416><!-- S BO --><!-- S IIMA --><TABLE cellSpacing=0 cellPadding=0 width=203 align=right border=0><TBODY><TR><TD> The AAIB said the engines failed to respond during landing

</TD></TR></TBODY></TABLE><!-- E IIMA -->The Air Accidents Investigation Branch (AAIB) published this statement on its website regarding the crash-landing of a British Airways flight at Heathrow.

http://newsimg.bbc.co.uk/nol/shared/img/66a.gif Following an uneventful flight from Beijing, China, the aircraft was established on an ILS approach to Runway 27L at London Heathrow.

Initially the approach progressed normally, with the autopilot and autothrottle engaged, until the aircraft was at a height of approximately 600ft and two miles from touch down.

The aircraft then descended rapidly and struck the ground, some 1,000ft short of the paved runway surface, just inside the airfield boundary fence.

The aircraft stopped on the very beginning of the paved surface of Runway 27L.

During the short ground roll, the right main landing gear separated from the wing and the left main landing gear was pushed up through the wing root.

A significant amount of fuel leaked from the aircraft, but there was no fire.

An emergency evacuation via the slides was supervised by the cabin crew and all occupants left the aircraft, some receiving minor injuries.

The AAIB was notified of the accident within a few minutes and a team of inspectors including engineers, pilots and a flight recorder specialist deployed to Heathrow.

<!-- S IBOX --><TABLE cellSpacing=0 cellPadding=0 width=208 align=right border=0><TBODY><TR><TD width=5>http://newsimg.bbc.co.uk/shared/img/o.gif</TD><TD class=sibtbg>http://newsimg.bbc.co.uk/nol/shared/img/v3/start_quote_rb.gif Following further demands for increased thrust from the autothrottle, and subsequently the flight crew moving the throttle levers, the engines similarly failed to respond. http://newsimg.bbc.co.uk/nol/shared/img/v3/end_quote_rb.gif




</TD></TR></TBODY></TABLE><!-- E IBOX -->

In accordance with the established international arrangements, the National Transportation Safety Board (NTSB) of the USA, representing the state of design and manufacture of the aircraft, was informed of the event.

The NTSB appointed an accredited representative to lead a team from the USA made up of investigators from the NTSB, the FAA [Federal Aviation Administration] and Boeing.

A Boeing investigator already in the UK joined the investigation on the evening of the event, the remainder of the team arrived in the UK on Friday 18 January.

Rolls-Royce, the engine manufacturer, is also supporting the investigation, an investigator having joined the AAIB team.

Activity at the accident scene was coordinated with the airport Fire and Rescue Service, the police, the British Airports Authority and British Airways to ensure the recovery of all relevant evidence, to facilitate the removal of the aircraft and the reinstatement of airport operations.

The flight crew were interviewed on the evening of the event by an AAIB Operations Inspector and the Flight Data Recorder (FDR), Cockpit Voice Recorder (CVR) and Quick Access Recorder (QAR) were removed for replay.

The CVR and FDR have been successfully downloaded at the AAIB laboratories at Farnborough and both records cover the critical final stages of the flight.



The QAR was downloaded with the assistance of British Airways and the equipment manufacturer. All of the downloaded information is now the subject of detailed analysis.

Examination of the aircraft systems and engines is ongoing.

Initial indications from the interviews and flight recorder analyses show the flight and approach to have progressed normally until the aircraft was established on late finals for Runway 27L.

At approximately 600ft and two miles from touch down, the autothrottle demanded an increase in thrust from the two engines, but the engines did not respond.

Following further demands for increased thrust from the autothrottle, and subsequently the flight crew moving the throttle levers, the engines similarly failed to respond. The aircraft speed reduced and the aircraft descended onto the grass short of the paved runway surface. The investigation is now focussed on more detailed analysis of the flight recorder information, collecting further recorded information from various system modules and examining the range of aircraft systems that could influence engine operation. http://newsimg.bbc.co.uk/nol/shared/img/99a.gif
<!-- E BO -->


</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>

[Half Bottle]

At approximately 600ft and two miles from touch down, the autothrottle demanded an increase in thrust from the two engines, but the engines did not respond.

Following further demands for increased thrust from the autothrottle, and subsequently the flight crew moving the throttle levers, the engines similarly failed to respond.
If (big if) this is not caused by fuel issues (or birdstrike, though that seems unlikely), these could be two sentences that cause sphincters in Everett to contract mightily.

[HalcyonDays]

If (big if) this is not caused by fuel issues....

I assume not now, given that the above report refers to quantities of fuel leaking from the aircraft.

[mks113]

Peliminary AAIB report...

<table border="0" cellpadding="0" cellspacing="0" width="760"><tbody><tr><td width="10"></td><td valign="top" width="629"><table border="0" cellpadding="0" cellspacing="0" width="629"><tbody><tr><td valign="top" width="629">
</td></tr></tbody></table><table border="0" cellpadding="0" cellspacing="0" height="32" width="629"><tbody><tr><td colspan="3">
</td></tr><tr><td valign="top" width="416">A significant amount of fuel leaked from the aircraft, but there was no fire.

</td></tr></tbody></table></td></tr></tbody></table>

Well, not a lack of fuel incident. Mismanagement or contamination are still available.

[Half Bottle]

I assume not now, given that the above report refers to quantities of fuel leaking from the aircraft.
It is suggestive, yes, but we still can't be certain. See mks113's points above.

[Willezurmacht]

It is damn peculiar. It is the timing of the loss of trust that concerns me. It begins to sound like a software problem.

[scottkin]

Anyone remember the issue in australia on what I think was a Quantas 777? From what I remember there was a major problem that was never diagnosed with the P.F.D. ...Very close to a disasterous ending. I believe it happened back in 2005. Issues with the autothrottles.

[Half Bottle]

Anyone remember the issue in australia on what I think was a Quantas 777? From what I remember there was a major problem that was never diagnosed with the P.F.D. ...Very close to a disasterous ending. I believe it happened back in 2005. Issues with the autothrottles.
There was a Malaysian 777 incident in 2005. I posted about it in the ad.com thread yesterday before the crash. Some kind of avionics 'gremlin'.

[fors43]

There was a Malaysian 777 incident in 2005. I posted about it in the ad.com thread yesterday before the crash. Some kind of avionics 'gremlin'.

Was there any post-incident schipincter tightening?

[Verbal]

If (big if) this is not caused by fuel issues (or birdstrike, though that seems unlikely), these could be two sentences that cause sphincters in Everett to contract mightily.Actually it was the undercooked lasagna from the Everett cafeteria.

[Half Bottle]

Was there any post-incident schipincter tightening?It was odd -- there were several ad.com threads about it but they all ended essentially with, "the investigation continues," then nothing since 2005.

Perhaps Verbie has some better knowledge on the sphincteral impacts.

[Verbal]

...the sphincteral impacts.Are you Alpaca?

[fors43]

So Verbs and HB, you two were two timing on JP.net and AD.com?

[Half Bottle]

So Verbs and HB, you two were two timing on JP.net and AD.com?I did sign up here long ago, but didn't post before yesterday.

[reubee]

There was a Malaysian 777 incident in 2005. I posted about it in the ad.com thread yesterday before the crash. Some kind of avionics 'gremlin'.

Halfie,

The server crashed yesterday as I was attempting to post this link for you.

http://www.atsb.gov.au/publications/investigation_reports/2005/AAIR/pdf/aair200503722_001.pdf

Combination of part failure, and software not coping with what happens if x, then y, then z occurs.

[FlyingPhotog]

Here's a preliminary report from yesterday's incident:

http://i.a.cnn.net/cnn/2008/images/01/18/report.heathrow.pdf

[Half Bottle]

Halfie,

The server crashed yesterday as I was attempting to post this link for you.

http://www.atsb.gov.au/publications/investigation_reports/2005/AAIR/pdf/aair200503722_001.pdf

Combination of part failure, and software not coping with what happens if x, then y, then z occurs.Thanks, reubee. Interesting read, but even in my armchair investigators fantasy world, I doubt we'll be able to connect the incidents. Except maybe in the general realm of unforseen failure modes (if, in fact, this one is a systems issue in the end).

[aussiepax]

Peliminary AAIB report...

<TABLE cellSpacing=0 cellPadding=0 width=760 border=0><TBODY><TR><TD width=10></TD><TD vAlign=top width=629><TABLE cellSpacing=0 cellPadding=0 width=629 border=0><TBODY><TR><TD vAlign=top width=629>Last Updated: Friday, 18 January 2008, 17:57 GMT http://newsimg.bbc.co.uk/shared/img/o.gif http://newsimg.bbc.co.uk/nol/shared/img/v3/dot_629.gif



<TABLE cellSpacing=0 cellPadding=0 width=416 border=0><TBODY><TR><TD width=213></TD><TD width=203></TD></TR></TBODY></TABLE>



</TD></TR></TBODY></TABLE><TABLE cellSpacing=0 cellPadding=0 width=629 border=0><TBODY><TR><TD colSpan=3>In full: AAIB initial statement







</TD></TR><TR><TD vAlign=top width=416>At approximately 600ft and two miles from touch down, the autothrottle demanded an increase in thrust from the two engines, but the engines did not respond.



Following further demands for increased thrust from the autothrottle, and subsequently the flight crew moving the throttle levers, the engines similarly failed to respond. The aircraft speed reduced and the aircraft descended onto the grass short of the paved runway surface. The investigation is now focussed on more detailed analysis of the flight recorder information, collecting further recorded information from various system modules and examining the range of aircraft systems that could influence engine operation. http://newsimg.bbc.co.uk/nol/shared/img/99a.gif
<!-- E BO -->





</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>


So for us non-pilots, in general terms could I please ask :

1) at which altitude would the autopilot / autothrottle be usually turned off and the plane manually landed - assuming this wasn't a Cat III ILS approach , was it ?


2) how do the pilots know that the autothrottle isn't responding other than vsi or ias indicators i.e is there a separate warning alarm

3) does the 777 have a toga switch that could be used, or is 600 feet too little time to respond?


These may be obvious to you guys , but this interested passenger is hazy on it . Thanks !

[AndyToop]

You're kidding right?

Nothing against the fine ATC folks, but what exactly do you think they did for a crew that had a dual engine flameout on short final aside from offering..."Good Luck, we're all counting on you!"

For the incident craft - they stopped the queue of planes behind them landing on top of them. For all of the other planes in the sky, they assisted in getting them to an alternate while Heathrow was shut. Then when it re-opened they helped get them in and out on a single runway. But appart from that yeah they probably just sat and looked on!

[AndyToop]

That video in the post a few pages back... Am I right in thinking it has been cut short because of the investigation?

If so why would they do that? To what end?

No it wasn't cut for the investigation, the video was sent to the BBC by someone who had filmed it on their phone from a truck. its only 9 seconds (lots of older phones only take a few seconds video at a time). I was watching BBC News24 when they first aired it last night. The anchor they had down at Heathrow had me in stitches. They showed the video and then he was all serious and melodramatic and said somethin along the lines of "We will be passing this video along to the investigation team. It could be a key item in them identifying the cause of this crash". Then there was a pause for a second while he thought about it then he said "Of course they do also have the pilots and the plane itself."

[Kjell Engkrog]

(....) they probably just sat and looked on!

Ya think? Ever worked a tower? You`d be surprised at the length of those call lists you have to go through once the crash button have been pressed. No, I don`t think they just sat and looked on.

Cheers,

[Shaggy]

Ya think? Ever worked a tower? You`d be surprised at the length of those call lists you have to go through once the crash button have been pressed. No, I don`t think they just sat and looked on.

Cheers,

My thoughts exactly

[Kjell Engkrog]

So for us non-pilots, in general terms could I please ask :



2) how do the pilots know that the autothrottle isn't responding other than vsi or ias indicators i.e is there a separate warning alarm

Thanks !

I`ll take a swing at #2. The autothrottle on the 777 also moves the throttles, and at that stage in the approach the PF would probably have his (left, in this case) hand over them. So he would feel the throttles move, but see that the descent rate was not arrested, and a instrument scan would also show no increase on the engine gauges.

Cheers,

[Jorge]

I did sign up here long ago, but didn't post before yesterday.

You made over 100 posts since yesterday?

[AndyToop]

I'm really curious to know if those engines were generating any thrust at all. The way the prelim is written it makes it sound like they were running, but wouldn't spool up when commanded. But looking at the phots of the engines and the dirt marks on the side of the plane, it looks like they weren't running at all when it hit the grass. Does the autothrottle kick off if it detects an engine shut down. My guess is no as logically you would want the earliest command of increased thrust to the other engine. If this was the case, then at 600ft and 2 miles out (whats that about 90 seconds from touchdown?) they lost the engines - autothrottle commanded increased thrust as speed started decaying - PF also recognises speed loss and with no time to check out whats happening commands full throttle.

If that is the case then big kudos to the PF for getting it over the fence and onto the grass, seat of the pants flying if ever there was. Judgement reserved on the frying pan sized medal until we know why the engines stopped.

[Half Bottle]

You made over 100 posts since yesterday?That's right. I really crank up my posting around crashes (both airplane and forum). Getting both on the same day has me on a logorithmic upslope.

[AndyToop]

Ya think? Ever worked a tower? You`d be surprised at the length of those call lists you have to go through once the crash button have been pressed. No, I don`t think they just sat and looked on.

Cheers,

Damn I got used to people not needing emoticons and who knew the ironing when they saw it.

[Half Bottle]

Damn I got used to people not needing emoticons and who knew the ironing when they saw it.It must be something in the water. That kind of thing never happened at ad.com.

[3WE]

There was a Malaysian 777 incident in 2005. I posted about it in the ad.com thread yesterday before the crash. Some kind of avionics 'gremlin'.......and the US/Boeing thought police were promptly dispatched to irreversibly destroy the AD.com fora, and ITS never existed.

[flyingspark]

Looking at the close up pics of the engines it looks like they were not operating at all. I am (definately) no expert but if they were turning then surely the fan blades would have been bent when the engine housing crumpled. Admittedly I have only seen a photo of 1 engine so I am happy to be corrected.

Clive

(2nd post and counting)
I'm really curious to know if those engines were generating any thrust at all. The way the prelim is written it makes it sound like they were running, but wouldn't spool up when commanded. But looking at the phots of the engines and the dirt marks on the side of the plane, it looks like they weren't running at all when it hit the grass. Does the autothrottle kick off if it detects an engine shut down. My guess is no as logically you would want the earliest command of increased thrust to the other engine. If this was the case, then at 600ft and 2 miles out (whats that about 90 seconds from touchdown?) they lost the engines - autothrottle commanded increased thrust as speed started decaying - PF also recognises speed loss and with no time to check out whats happening commands full throttle.

If that is the case then big kudos to the PF for getting it over the fence and onto the grass, seat of the pants flying if ever there was. Judgement reserved on the frying pan sized medal until we know why the engines stopped.

[flyingspark]

ITN news here in the UK just reported that todays flight from Beijing to LHR was delayed due to extra fuel checks and contamination concerns. They also said that the remaining fleet was also to be checked. B.A have made no comment. Could just be reporter hype.

[AndyToop]

ITN news here in the UK just reported that todays flight from Beijing to LHR was delayed due to extra fuel checks and contamination concerns. They also said that the remaining fleet was also to be checked. B.A have made no comment. Could just be reporter hype.

I still find it very hard to conceive of a fuel contamination that lets you fly 10 hours then kills both engines simultaneously.

[tds]

I still find it very hard to conceive of a fuel contamination that lets you fly 10 hours then kills both engines simultaneously.The suggestion on FlightGlobal was contamination that froze solid at altitude, then thawed and remixed on descent, at which point it constituted a much higher percentage of the remaining contents.

Absolutely no idea if that's remotely plausible.

[procede]

I still find it very hard to conceive of a fuel contamination that lets you fly 10 hours then kills both engines simultaneously.

The only thing which could have caused fuel starvation of the engines is a fuel management issue, such as selecting feeds of empty tanks.

A VS A346 had a similar problem, where at least one engine quit (and another one was about to), forcing it to make an unplanned landing at AMS.

[AndyToop]

The suggestion on FlightGlobal was contamination that froze solid at altitude, then thawed and remixed on descent, at which point it constituted a much higher percentage of the remaining contents.

Absolutely no idea if that's remotely plausible.

He He - anyone know if superfueler made it over - there's one I haven't seen in the best of AD.com list yet

[gbasco]

http://www.jetphotos.net/news/index.php?blog=1&title=aaib-ba-jet-s-engines-failed-to-respond&more=1&c=1&tb=1&pb=1

Besides contamination, what other things can cause for both engines to stop responding?

Cheers,

Gabe

[AndyToop]

From the initial report it looks like fuel on board wasn't the issue (still remains to see if the fuels was in the right place relative to the feed settings). The photos seem to rule out a birdstrike and you would have thought it would have got a mention in the preliminary report.

Another thing occurs to me with contamination - why just this plane?
Too much for my tired brain at the minute.

[Half Bottle]

http://www.jetphotos.net/news/index.php?blog=1&title=aaib-ba-jet-s-engines-failed-to-respond&more=1&c=1&tb=1&pb=1

Besides contamination, what other things can cause for both engines to stop responding?

Cheers,

Gabe
I think the consensus of the parlour right now is that if it's not a fuel issue (and a fuel issue would probably not affect both engines simultaneously, would it? Maybe mis-selected tanks?) and it's not a bird strike, then you're looking at some kind of nasty, unknown failure mode of the engine control systems. My questions would be what kinds of failure modes could create such a dual power failure (or severe reduction)?

Auto-throttles? If so, then why not corrected with manual input?
FADEC?
FMC?
Other?

[Alessandro]

Electric failure seem to be very rare, pre-2008 that is,
http://aviation-safety.net/database/dblist.php?Event=ACSE

[Tbun]

That video in the post a few pages back... Am I right in thinking it has been cut short because of the investigation?

If so,, to what end?

[Steve_7]

AD.Com forums gone bye-bye forthwith. This notice is up

"Dear AirDisaster.Com Forum members,

At about 3pm U.S. Pacific Time today, the web server that hosted the AirDisaster.Com forums suffered a catastrophic failure which rendered both
hard drives useless and irrecoverable. Unfortunately, one drive in this server contained the live forums database, and the other contained the daily
database backups.

With this in mind, I'm sorry to report that, effective immediately, the AirDisaster.Com Discussion Forums are closed permanently. These forums were
home to hundreds of thousands of posts, and to attempt to start from scratch at this point would be futile, in my opinion.

For those of you looking for a place to continue discussing aviation safety, we have introduced a new Aviation Safety Discussion Forum (http://forumdisplay.php?f=29) at our sister site,
JetPhotos.Net. While I know this isn't the ideal solution for many of you, I would still invite all of you to visit the JP.Net forums, sign up, and
participate!

On a personal note, to me, this is the end of an era. These forums were regarded as the most authoritative aviation safety forums on the internet,
for a period of almost 10 years. On top of that, they were home to many friendships, some rivalries, and spawned at least one successful marriage.
That, above all else, will be the legacy of these forums long after they're gone.

I'd like to thank each and every one of you who helped to make the forums as successful as they were, and would like to thank, especially, the
administrators, moderators, and industry forum hosts who devoted their free time to make this place the best it could possibly be.

I guess that's about it. I hope to see many of you over at the JetPhotos.Net forums, and to those of you who will no longer participate, the best to all of you for a bright and prosperous future.

Last one out, hit the lights!

Chris Kilroy
Editor, AirDisaster.Com

Chris K., I've had AD.com on my bookmarks for 5yrs. and just finished
reading the 100+ pages of the GOL - Embrer disaster. That took 3 nights
of solid reading to get through. I had intended to join the site and when I
read of the 777 at Heathrow I immediately went to AD.com to get the
latest. I was sadly suprised to find the site terminated. Please accept my
heartfelt condolences at the demise of your first-rate site. DO NOT LISTEN
to the idiot who keeps insulting you over the severe crash of AD.com, I'm
now a member here and will now get my feet wet as a novice who has
always had a deep interest in all things aviation related. Thanks for the
last 5yrs. on your great site!!!

[brianw999]

Auto-throttles? If so, then why not corrected with manual input?
They did...and it still went pear shaped !

[Lars2]

Autobrakes triggered before touchdown for some unknown reason?

[Steve_7]

They did...and it still went pear shaped !

When the aircraft is in landing config., how quickly does momentum
decay ( at or below 1000ft.)?

[Chris Kilroy]

Autobrakes triggered before touchdown for some unknown reason?

What?

[Lars2]

Just a question... Could be possible?

[tds]

Just a question... Could be possible?Autobrakes on the landing gear wheels?

[einesellesenie]

I think the consensus of the parlour right now is that if it's not a fuel issue (and a fuel issue would probably not affect both engines simultaneously, would it? Maybe mis-selected tanks?) and it's not a bird strike, then you're looking at some kind of nasty, unknown failure mode of the engine control systems. My questions would be what kinds of failure modes could create such a dual power failure (or severe reduction)?

Auto-throttles? If so, then why not corrected with manual input?
FADEC?
FMC?
Other?

FADEC: isn't it "one per engine" (would bring us back to a rare simultaneous failure)?

FMC: maybe, but this is a Boeing ;)

Core lock due to multiple "dudes" being issued in the cockpit during approach?

[Lars2]

Autobrakes on the landing gear wheels?

Yes, this was just a thought. Only an expert can answer.

The mechanical braking action won't do anything until on the ground, of course.
But could bring the engines to idle, activate spoilers also?

[Dmmoore]

Autobrakes triggered before touchdown for some unknown reason?

Lars2,
Auto brakes apply the wheel brakes only. No effect in the air.

Auto spoilers deploy only after the main gear struts are compressed (touch down) and the engines are both at idle.

[Dmmoore]

When the aircraft is in landing config., how quickly does momentum
decay ( at or below 1000ft.)?

Gear down, flaps down, speed bleeds off quickly. The rate of descent of a 747-200 (not a 777) with old style steam gages, power off and flaps 30 to maintain 180 knots is almost 3000 FPM with a pitch down almost a full dot on the (flight director Indicator) FDI.

[Dmmoore]

Looking at the close up pics of the engines it looks like they were not operating at all. I am (definately) no expert but if they were turning then surely the fan blades would have been bent when the engine housing crumpled. Admittedly I have only seen a photo of 1 engine so I am happy to be corrected.

Clive

(2nd post and counting)

The problem is an engine at idle thrust (as these would be before the engines contacted any damage that stopped them) would not shop very much blade damage. The photo proves the engines were not operating at high power and that's about all.

[Dmmoore]

The suggestion on FlightGlobal was contamination that froze solid at altitude, then thawed and remixed on descent, at which point it constituted a much higher percentage of the remaining contents.

Absolutely no idea if that's remotely plausible.

It is plausible, just but plausible.

[FlyingPhotog]

Autobrakes triggered before touchdown for some unknown reason?

Do you mean thrust reversers?

[Jorge]

It is plausible, just but plausible.

Hmm, your answer sounds like a Myth Busters episode.

[FlyingPhotog]

The YouTube crash video link no longer works, does anyone have a working one?

[aardvark2zz]

What's a power panel ? :-)


......Inquiries by the Air Accidents Investigation Branch appear to rule out any form of pilot error in the approach for landing. One area of specific interest will be the electrical system after it emerged yesterday that there had been at least 12 serious incidents of overheating, causing "major damage" to power panels on at least four occasions.

The initial findings of investigators are based on interviews with the pilots and analysis of the black box flight recorder and cockpit voice recorder......


http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=509163&in_page_id=1770&ct=5

[Dmmoore]

Hmm, your answer sounds like a Myth Busters episode.

Exactly. It only works when everything else is proven operational. :)

[AJ]

At approximately 600 ft and 2 miles from touch down, the Autothrottle demanded an increase in thrust from the two engines but the engines did not respond. Following further demands for increased thrust from the Autothrottle, and subsequently the flight crew moving the throttle levers, the engines similarly failed to respond. The aircraft speed reduced and the aircraft descended onto the grass short of the paved runway surface.
http://www.aaib.dft.gov.uk/latest_news/accident__heathrow_17_january_2008___initial_report.cfm

This does not signify an autothrottle fault as all the system does is drive servos to drive up the thrust in lieu of the PF's hand!

There have been issues on our aircraft of lack of thrust response to more than one engine but fortunately it has always been in cruise flight and only in GE powered aircraft.

A double failure of RRs has me stumped.

[Cam]

^AJ, in those cases...what was determined to be the problem?

On a modern 777, how are the actually throttles connected to the engines? What is the "line of command" from where the crew puts their hands on the levers to the unit in the engine that adjusts the fuel and air mixture.

(Think about a throttle in a car, that's what I'm getting at)

[Gulfstream]

After the first report, I was thinking it had to be windshear ...

Now, it seems like it is either a software issue, a massive bird strike, or fuel contamination.

Hopefully it's not a software issue ... unlikely given the 777's flawless record. Fuel contamination would be interesting.

[aardvark2zz]

After the first report, I was thinking it had to be windshear ...

Now, it seems like it is either a software issue, a massive bird strike, or fuel contamination.

Hopefully it's not a software issue ... unlikely given the 777's flawless record. Fuel contamination would be interesting.

Say what !? Read the following. Very interesting programming bug !

See Fig 1. and previous text.

http://www.atsb.gov.au/publications/investigation_reports/2005/AAIR/pdf/aair200503722_001.pdf


excerpt

Testing, disassembly and examination of the ADIRU
--------------------------------------------------

........confirmed the presence of faults in two internal accelerometers8 and one ring-laser
gyroscope9 (gyro). It was determined that the ADIRU’s accelerometer number-6
failed at the time of the occurrence, and that accelerometer number-5 failed in June
2001, but was still capable of producing high acceleration values or voltages that
were erroneous

10. The component manufacturer reported that a search of all field
history records showed that there were a total of four other occasions when two
accelerometers had failed in other ADIRUs of the same type. None of these cases
resulted in reported erroneous output, indicating that the accelerometer hardware
failure modes in these cases had not produced similar high accelerometer
value/voltage.


Further investigation revealed that the conditions necessary for the occurrence were
(figure 1):
– an accelerometer failure producing high value/voltage output
– the ADIRU excluding that failed accelerometer from use in its acceleration
computations
– power to the ADIRU cycled (system reset)
– a second accelerometer then failing and the latent software anomaly allowing
the ADIRU to once more utilise the previously failed accelerometer
information with its high output values in its computations, resulting in
erroneous acceleration outputs into the flight control outputs but not the
navigation (ground speed, velocity, position, etc.) outputs.

Figure 1: Component event flow chart

June 2001, accelerometer
#5 fails with erroneous high
output values, ADIRU
disregards accelerometer
output values

Power Cycle on ADIRU
(occurs each occasion
aircraft electrical system is
shutdown and restarted)

August 2005, accelerometer
#6 fails, latent software
anomaly allows uses of
previously failed
accelerometer #5 output.

9M-MRG upset
event




.

[aardvark2zz]

Transcribed the following from Jay Leno's Friday night monologue and closed caption: Not my errors.

And yesterday they had a big crash landing in London with a 747, lucky nobody was killed but, you know I heard a guy from the FDA say that's not good enough for us, we're not gonna rest until we've reached our goal of 0 plane crashes, that's our goal 0 plane crashes, and everybody applauds......

well of course 0 is the goal.

What are you gonna say ?? We just want 1 big crash a year, that's all we want, give us 1 huge crash and were fine.

.

[Shorrick Mk2]

The problem is an engine at idle thrust (as these would be before the engines contacted any damage that stopped them) would not shop very much blade damage. The photo proves the engines were not operating at high power and that's about all.

True - however if APU autostart happened (which was a suggested possibility based on the APU intake being open) would that not indicate that the engines were not at merely idle thrust?

[turbotraker]

A double failure of RRs has me stumped.

Just out of interest AJ, if this was 747 or another 4 engined aircraft, how likely would it have been that all 4 engines lose power? Just wondering if there was any truth in Richard Bransons claim of 4 engines vs 2?

Murt

[L1011]

^AJ, in those cases...what was determined to be the problem?

On a modern 777, how are the actually throttles connected to the engines? What is the "line of command" from where the crew puts their hands on the levers to the unit in the engine that adjusts the fuel and air mixture.

(Think about a throttle in a car, that's what I'm getting at)

Electro-mechanical ( mechanical - electro :-)... ) link to a solenoid

[SammyG]

I'm gonna throw this out there, admittedly having no idea what I'm talking about, on the 1 in a million chance I turn out to be right.

They will determine that someones cell phone onboard somehow caused the engines fuel cutoff valves to be commanded closed.

[flyingspark]

BBC Radio 2 Friday.

A discussion was taking place about BA038. A guy phoned up and was amazed that no one had thought of the theory that a passenger activating his mobile (cell) phone had caused the engines to fail.:lol:
On another thought, could severe wake turbulence mess up the air flow enough to screw the engine thrust?? It doesn't look like that happened here but could it happen?

[nickappel]

How long do you think the plane will be in that spot?

[BA747-436]

"The delicate task of moving the aircraft to the engineering base is now underway led by BA engineering in conjunction with the AAIB. They are being assisted by the RAF and BAA. It is likely to take some time and will be dependent on the weather conditions. Once the aircraft has been moved work will commence to return the runway to full operation."

Source: Guarenteed but undisclosed.

[busfan]

FADEC: isn't it "one per engine" (would bring us back to a rare simultaneous failure)?

FMC: maybe, but this is a Boeing ;)

Core lock due to multiple "dudes" being issued in the cockpit during approach?

I don't think BA hires "dudes" ala the NWA RJ...:nonono:

[Dmmoore]

True - however if APU autostart happened (which was a suggested possibility based on the APU intake being open) would that not indicate that the engines were not at merely idle thrust?

It depends on what started the APU. You can't assume it auto started because the engines shut down. It may have but was it running because the crew started it prior to making the approach? Did it auto start because an engine driven generator tripped? You can't tell from the picture.

All of these will be known when the DFDR is read.

[Dmmoore]

BBC Radio 2 Friday.

A discussion was taking place about BA038. A guy phoned up and was amazed that no one had thought of the theory that a passenger activating his mobile (cell) phone had caused the engines to fail.:lol:
On another thought, could severe wake turbulence mess up the air flow enough to screw the engine thrust?? It doesn't look like that happened here but could it happen?

"Anything "COULD" happen! :grin:
Realistically, No. Turbulence strong enough to flame out the engines would cause other problems that would lead to structural failure first.

[Dmmoore]

How long do you think the plane will be in that spot?

Until the physical investigation involving the aircraft resting in that location (not the cause but the result of the event) is complete. Usually 2 or 3 days. Then removal will begin. If the aircraft is to be written off, the aircraft may be dismantled. If it is to be recovered, It will be lifted in one major piece onto transport dollies and moved to a repair site.

The write off / vs repair decision will be or has been made by the Airline and their insurance carrier.

[L1011]

AAIB preliminary report here






http://www.aaib.dft.gov.uk/latest_news/accident__heathrow_17_january_2008___initial_report.cfm

[Willezurmacht]

I am still convinced that the coincidence of the engines stopping at that precise moment is an avionics/ software problem. Some tiny flaw that only happens when the conditions line up in a very specific manner.

[Vinco]

I thought I read earlier over on AD.com that an airport employee said that the engines were "screaming" as it came in for landing. Being familiar with the sound aircraft engines produce gives him some credibility. Is it possible that he came in two low/too slow to where even max power wasn't enough to bail him out?

[pelican98]

Originally Posted by Dmmoore
The write off / vs repair decision will be or has been made by the Airline and their insurance carrier.
If they opt to fix it, will pilots have a say in the process?
I also wonder if passengers would willingly board in if informed of the aircraft history, because of the jinx factor.
My guess is they are going to scrap it. salvage the good parts to use maintaining other 777s if there is such a program.
ps: my condolence to ad.com, I loved that site for its expertise.

[HalcyonDays]

If they opt to fix it, will pilots have a say in the process?
I also wonder if passengers would willingly board in if informed of the aircraft history, because of the jinx factor.
My guess is they are going to scrap it. salvage the good parts to use maintaining other 777s if there is such a program.
ps: my condolence to ad.com, I loved that site for its expertise.

The decision will have nothing to do with the pilots. It will be a business decision between the owner (in this case, the airline) and the insurers. It would certainly be valuable parted out. If it is declared a hull loss, I would expect it to raise comfortably in excess of $100m, since it is a young airframe (2001).

[Schorsch]

I am still convinced that the coincidence of the engines stopping at that precise moment is an avionics/ software problem. Some tiny flaw that only happens when the conditions line up in a very specific manner.


I disagree. The engine control systems are around for over 20 years now. The differences to previous RR engine models or previous Boeing models are limited, the basic software is rarely changed as it is certified and works. The circumstances were in no way specific. The aircraft is neither very young nor very new. It doesn't belong to some austere carrier. The B777 fleet has accumulated well above 1 million flight hours and most likely 100000 cycles/landings. If a technical problem within the software exists why should it surface exactly now? And why at a similar time on both engines?

The most striking thing is the failing of the engines at precisely the same moment. A fuel starvation (for example due to wrong pumping; fuel on board was enough) would have resulted in one engine failing first.

The theory of fuel contamination sounds somehow plausible, at least it would explain some issues. A double flame out is rather unlikely, if anything went into the engines (ash etc) the question is why no other aircraft was affected.

This remains a delicate issue. Should an uncommanded engine shut down have occured and if it is not attributable to a failure of either the pilots, the airline or the fuel, Boeing and Rolls Royce have a major problem, not to speak of the carriers that use the B777.

[sjwk]

I thought I read earlier over on AD.com that an airport employee said that the engines were "screaming" as it came in for landing.
I'd read similar reports - although I saw one report attribute that to someone on the ground and another one to a passenger. "Screaming" engines to me suggested they were doing something so maybe the sound was from something else? I also read something that said the plane dropped as soon as the undercarriage was lowered - would that just be because the drag lowered speed more, or could something associated with the undercarriage have damaged control cables or similar? Stowaways lighting campfires in the wheel-wells for instance? :)

Unfortunately I can't find the references to either of those, the BBC have an annoying habit of rewriting their articles with new findings, dropping the less newsworthy bits out rather than leave published articles alone and creating new ones..

Steve.

[JordanD]

:lol: Cell phone.

[Princess Leia]

The decision will have nothing to do with the pilots. It will be a business decision between the owner (in this case, the airline) and the insurers. It would certainly be valuable parted out. If it is declared a hull loss, I would expect it to raise comfortably in excess of $100m, since it is a young airframe (2001).

I sincerely doubt that.

The most valuable parts (Landing gear and engines/pylons) are worth scrap value. The high lift devices are mostly or all damaged. You're really looking at avionics, the empinnage and the APU, as well as varouus pumps for reuse. The interior will stay with BA, the rest is scrap.

[L1011]

Gonna stick my neck out here & say fuel contamination.

Water coming out of chilled supension as it reached lower altitudes, no flame out but a loss of power.

Ok DMM, tell me it couldnt happen to both engines at the same time maybe ?
:-)

[scottkin]

my bet is on the avionics. Dual engine out because of fuel contamination at the same time would almost be impossible.

[Robert Hilton]

Gonna stick my neck out here & say fuel contamination.

Water coming out of chilled supension as it reached lower altitudes, no flame out but a loss of power.

Ok DMM, tell me it couldnt happen to both engines at the same time maybe ?
:-)
It would take an inordinate amount of water to do that. I've actually tapped a bucket of water out of a collector tank with no indication from the engines. It is also a very rare event, I've only tapped that much once.
The question still remains why did the engines wind down?
Lack of fuel. (The amount of fuel at the crash site would negate this)
Fuel in the wrong place.
Uncommanded shut-down (on two engines unlikely)
Accidental shut-down (again unlikely)
Total power failure (I'm lead to believe with FADEC this is nigh impossible)

In any event we'll have to wait and see what comes off the the DFDR.

[Dmmoore]

Gonna stick my neck out here & say fuel contamination.

Water coming out of chilled supension as it reached lower altitudes, no flame out but a loss of power.

Ok DMM, tell me it couldnt happen to both engines at the same time maybe ?
:-)

I've already said its a remote possibility but even then, both engines at the exact same time!

One engine followed shortly by the other okay, but the same time!

If there is /was contamination, the engine fuel filters will tell the story.

[Dmmoore]

The decision will have nothing to do with the pilots. It will be a business decision between the owner (in this case, the airline) and the insurers. It would certainly be valuable parted out. If it is declared a hull loss, I would expect it to raise comfortably in excess of $100m, since it is a young airframe (2001).

Actually it won't bring much on the scrap market (See P.L.'s post) which is one reason it may be repairable. It may be a 50+ Million USD repair bill but that is cheaper than a replacement aircraft from a heavily booked production line.

The fuselages are relatively easy to repair. It's the wings that will determine the aircraft's fate. Damage very much of the wing box structure and repair with out a fixture (jig) to hold everything in place becomes an issue.

[Dmmoore]

my bet is on the avionics. Dual engine out because of fuel contamination at the same time would almost be impossible.

I'm with you on the electronics. The questions are what? Why now? And was this a unique event?

[aardvark2zz]

I disagree. The engine control systems are around for over 20 years now. The differences to previous RR engine models or previous Boeing models are limited, the basic software is rarely changed as it is certified and works. The circumstances were in no way specific. The aircraft is neither very young nor very new. It doesn't belong to some austere carrier. The B777 fleet has accumulated well above 1 million flight hours and most likely 100000 cycles/landings. If a technical problem within the software exists why should it surface exactly now? And why at a similar time on both engines?

The most striking thing is the failing of the engines at precisely the same moment. A fuel starvation (for example due to wrong pumping; fuel on board was enough) would have resulted in one engine failing first.

The theory of fuel contamination sounds somehow plausible, at least it would explain some issues. A double flame out is rather unlikely, if anything went into the engines (ash etc) the question is why no other aircraft was affected.

This remains a delicate issue. Should an uncommanded engine shut down have occured and if it is not attributable to a failure of either the pilots, the airline or the fuel, Boeing and Rolls Royce have a major problem, not to speak of the carriers that use the B777.

I disagree,

see post and report referenced at

http://forums.jetphotos.net/showpost.php?p=449104&postcount=160

August 2005,
- accelerometer #6 fails,
- latent software anomaly allows uses of previously failed accelerometer #5 output.
- upset event

It was a software bug that was discovered only when the 2nd set of accelerometers failed. It appears the 1st set had intermittent problems and was never fully repaired.

The 777 near 40000 ft pitched up and climbed at 10000 fpm !!??? Stick shaker activated.

Anyone know the AOA for stall ?

Swiss cheese holes allowed to align.
.

[Robert Hilton]

I'm with you on the electronics. The questions are what? Why now? And was this a unique event?
If a FADEC engine loses all power doesn't it retain the last power setting selected?

[Dmmoore]

If a FADEC engine loses all power doesn't it retain the last power setting selected?

It wouldn't have to be FADEC related although it seems like the likely place to start looking. The system is multi channel and well protected but "IF" the throttles were at a low power setting when a total power failure occurred, including signal loss from the cockpit throttle resolvers, the engines would stay at the last commanded thrust setting.

[Lars2]

Do you mean thrust reversers?

Brakes, spoilers and reversers altogether.
This was just a thought. Well, I know, it's not very likely.
But as others also said, it is even more unlikely that two engines fail at the same moment for "no" reason. So I thought, the shutdown or idle power was somehow electronically commanded.
If the sensor falsely reported touchdown (maybe a mechanical problem in the landing gear with excessive forces?), what would happen?
The brakes themselves won't show an effect in the air.
But what would happen to engines and spoilers. The latter would lead to a stall, if they deploy.
The engines? If they are commanded into reverse, would they do this? Would they shut down or go into idle? I guess, there are additional safenty features, which quit an engine if going into reverse in the air, right?
Someone also heard a "screaming engine"? Saying this knowningly such witnesses aren't highly reliable.

[Gabriel]

These are different systems. I'm not expert in this field (airliners systems) but I think I will not be too far from the truth:

If the spoilers are armed, they deploy upon touchdown based on a logid that combines struts compressin, weels speed, and height above the runway.

The autobrakes only act on the weels and, if set, start to apply weels brakes upon touchdown too.

The reversers cannot be operated before touchdown (a mechanical lock will prevent that). Even after touchdown, they cannot be operated unless the power levels are at idle. And even then, only the human pilot can opperate the autothrottles.

A failure in whatever sensors could have deployed the spoilers too early? Very unlikely, but now the AAIB reports that the engine failed to respond to increased power commands both from the autothrottles and the pilot (both the human pilot and the auto one move the power levers to command a thrust change). So a spilers malfunctin is not in line with this.

A failure in the autobrakes can by no means be related with the accident, since the aerodynamics doesn't know or care whether the weels are braked or not.

An uncommanded reverser deployment in flight has happened beofre (Lauda), but not in this type of aircraft and actions have been taken to address the cause. And never in more than one engine at a time.

[PIKTEAM]

http://news.bbc.co.uk/1/hi/england/7196172.stm

me

[Dmmoore]

Do you mean thrust reversers?

Brakes, spoilers and reversers altogether.
This was just a thought. Well, I know, it's not very likely.
But as others also said, it is even more unlikely that two engines fail at the same moment for "no" reason. So I thought, the shutdown or idle power was somehow electronically commanded.
If the sensor falsely reported touchdown (maybe a mechanical problem in the landing gear with excessive forces?), what would happen?
The ground sensing system operates through independent switches on the landing gear struts, Both main and nose gear struts have them. Two switches must close or two pair of wheels (one on each main gear) must spin up (above 100 knots) before the aircraft knows its on the ground.
The brakes themselves won't show an effect in the air.
But what would happen to engines and spoilers. The latter would lead to a stall, if they deploy.
Speed brakes and spoilers are the same things (almost) with different functions. When used as speed brakes, panels on the upper trailing edge of each wing raise together as commanded by the cockpit control. In the lateral control mode, panels on the descending wing raise to assist the ailerons with roll control. As ground spoilers, all panels on both wings raise to their full up position upon touch down and not before. Ground spoilers require the aircraft on ground signal before they will activate. In the event the impossible happened, the handle in the cockpit will move aft to the extend mark, spoilers extend will be displayed. in other word's can't happen.
The engines? If they are commanded into reverse, would they do this? Would they shut down or go into idle? I guess, there are additional safety features, which quit an engine if going into reverse in the air, right?
Someone also heard a "screaming engine"? Saying this knowningly such witnesses aren't highly reliable.
After the Lada 767 engine in-flight reverse accident, an additional safeguard was installed. Some of us call it the TLOD (Third Line Of Defense) lock, others call it the Lada lock, in any event. The cockpit wiring can signal the reverser to activate and nothing will happen until the Aircraft On Ground circuitry is satisfied. Then the mechanical lock is removed and the cockpit controls can signal the reverser to cycle.
In this case the reverser's on both engines are stowed, they did not function in flight.

[ils26]

I notice that BA calls this an "incident". Why?

At least according to NTSB (http://www.ntsb.gov/Info/gils/gilsac.htm)

an accident is "an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, and in which any person suffers death or serious injury, or in which the aircraft receives substantial damage", and
an incident is "an occurrence other than an accident, associated with the operation of an aircraft, which affects or could affect the safety of operations."
As I recall there are people that are categorizes as seriously injured and the damages to the aircraft could (at least if you ask me) be considered substansial, thus making this an accident. The AAIB calls it an accident.

// ils26

[flyingspark]

News paper here today, (I think it was the Guardian) reporting that the throttles were in the fully open position when inspected. Also stating that the audible warning system which alerts the crew to engine / thrust problems (would that be eicas) was inoperative for the flight. Could just be news hype again but if not would this be covered under the MEL?

[sjwk]

I'll show my ignorance now (and it won't be for the last time).. would the engines normally be running from independant fuel tanks, or would they be running from a common tank? Or could it be either scenario? I know there are multiple tanks, and that fuel can be pumped from tank to tank, but I don't know how the fuel system is physically plumbed as far as getting it to the engines goes?

My point really is that *if* the engines are running from different tanks, it would be much more unlikely that a contaminant would thaw at exactly the same time in two places. Likewise, there would need to be multiple simultaneous pump failures surely?

Steve.

[Tbun]

http://news.bbc.co.uk/1/hi/england/7196172.stm

me

So wheres the copies then?? Post them up. Dont tell me you are another one of those idiots who didnt copy the pics before handing them over?

[gbasco]

So wheres the copies then?? Post them up. Dont tell me you are another one of those idiots who didnt copy the pics before handing them over?


Seems he uploads here.

http://www.jetphotos.net/showphotos.php?userid=14505

Cheers,

Gabe

[Dmmoore]

I'll show my ignorance now (and it won't be for the last time).. would the engines normally be running from independant fuel tanks, or would they be running from a common tank? Or could it be either scenario? I know there are multiple tanks, and that fuel can be pumped from tank to tank, but I don't know how the fuel system is physically plumbed as far as getting it to the engines goes?

My point really is that *if* the engines are running from different tanks, it would be much more unlikely that a contaminant would thaw at exactly the same time in two places. Likewise, there would need to be multiple simultaneous pump failures surely?

Steve.

The engines normally feed from their own tanks. Crossfeeding (if required) would have been accomplished during cruise, descent and landing would have been with each engine feeding from its own tank.

Even if contaminated fuel is a factor, fuel pump failure need not be a factor. However even a large quantity of contamination were to enter both engines at the same time the chances that both engine filters would plug nd starve the engines at the same time is very unlikely.

[Half Bottle]

I may be reading too much into it, but for me the way the AAIB worded it:, "the Autothrottle demanded an increase in thrust from the two engines but the engines did not respond," leads me to believe we're looking at something downstream of the throttle and upstream of the engines.

It seems that a fuel-related issue most likely would not have simultaneously affected both engines. On the other hand, I haven't heard of anything related to the throttles or engines from an electronics perspective that is not fully redundant.

So, hypothetically -- if it is electronics -- what could it be? What's the weakest link in the electronics chain?

[Half Bottle]

I notice that BA calls this an "incident". Why?
BA calls it an incident for a simple reason: it's better PR than accident. But, yes, from an investigative perspective, I think there's very little question that it's an accident.

[Tbun]

What's the weakest link in the electronics chain?

Good question.

[Tbun]

Seems he uploads here.

http://www.jetphotos.net/showphotos.php?userid=14505

Cheers,

Gabe


Heres his post from Airliners dot net.

"<TABLE style="BORDER-RIGHT: #000000 1pt solid; PADDING-RIGHT: 0px; BORDER-TOP: #000000 1pt solid; PADDING-LEFT: 0px; PADDING-BOTTOM: 0px; BORDER-LEFT: #000000 1pt solid; PADDING-TOP: 0px; BORDER-BOTTOM: #000000 1pt solid; BORDER-COLLAPSE: collapse; border-spacing: 0" cellSpacing=0 cellPadding=0 width=728 border=0><TBODY><TR bgColor=#1b374c><TD><TABLE cellSpacing=3 cellPadding=0 width="100%" border=0><TBODY><TR bgColor=#1b374c><TD>E195 (http://www.airliners.net/discussions/profile.main?username=E195) http://cdn-www.airliners.net/discussions/graphics/flags/United_Kingdom.gif From United Kingdom, joined Jan 2007, 46 posts, RR: 1 (javascript:RRDisplay();)
Reply 4, posted<SCRIPT language=JavaScript type=text/javascript>s_lt(1200775341, 'l F j Y H:i:s');</SCRIPT> Sat Jan 19 2008 20:42:21 your local time<NOSCRIPT></NOSCRIPT> (6 hours 1 minute 51 secs ago) and read 6065 times:</TD><TD align=right bgColor=#1b374c>http://cdn-www.airliners.net/discussions/graphics/FCMember.gif (http://www.airliners.net/login/signup.main)</TD></TR></TBODY></TABLE></TD></TR><TR><TD bgColor=#1b374c>http://cdn-www.airliners.net/discussions/graphics/newtestline.jpg <TABLE style="TABLE-LAYOUT: fixed" width="95%" align=center border=0 valign="middle"><TBODY><TR><TD>My other post was deleted, but the person http://news.bbc.co.uk/1/hi/england/7196172.stm (http://news.bbc.co.uk/1/hi/england/7196172.stm) is me

im getting the pictures back tomorro and am passing on to my publisist to distribute them to the press and media agencies.

David</TD></TR></TBODY></TABLE>

</TD></TR></TBODY></TABLE>"

note... "im getting the pictures back tomorro and am passing on to my publisist to distribute them to the press and media agencies."




So we may see them after all! YAY for the internet!!

[HalcyonDays]

I sincerely doubt that.

The most valuable parts (Landing gear and engines/pylons) are worth scrap value. The high lift devices are mostly or all damaged. You're really looking at avionics, the empinnage and the APU, as well as varouus pumps for reuse. The interior will stay with BA, the rest is scrap.

If it's declared a total hull loss, the insurers in most circumstances will pay out an amount close to the residual value which existed the moment before the crash, or some other agreed value which will be close to such figure. If the aircraft had smashed into smithereens by flying into a mountain or disappeared by crashing into the ocean, the pay-out on declaration of an actual total loss would be the same even though in these circumstances the scrap value would be nil. Recent insurance pay-outs have included the TAM A320 at $41m and the China 737 at $45m. Hence my estimate for this 777 of $100m minimum.

[Dmmoore]

If it's declared a total hull loss, the insurers in most circumstances will pay out an amount close to the residual value which existed the moment before the crash, or some other agreed value which will be close to such figure. If the aircraft had smashed into smithereens by flying into a mountain or disappeared by crashing into the ocean, the pay-out on declaration of an actual total loss would be the same even though in these circumstances the scrap value would be nil. Recent insurance pay-outs have included the TAM A320 at $41m and the China 737 at $45m. Hence my estimate for this 777 of $100m minimum.

I think we had better wait for the insurance company and BA to figure out if they are going to repair or write it off before "WE" write it off for them.

[RadarContactLost]

I notice that BA calls this an "incident". Why?

Like HB says, it sounds better. Not an N-registered plane, not in US airspace, I don't know what the CAA/AIB rules are.

[RadarContactLost]

And I wonder if there will be any ETOPS worries. Is this our one in ten billion that just happened near an airport or will it make folks think? Of course, if something kills two engines it could just as well kill three or four.

[Half Bottle]

And I wonder if there will be any ETOPS worries. Is this our one in ten billion that just happened near an airport or will it make folks think? Of course, if something kills two engines it could just as well kill three or four.
Any thoughts on what 'this' could be, RCL? (If it's not fuel related, that is)?

I know we're in rampant speculation mode, but I'm just not educated enough to even come up with a couple of possible (even if unlikely) scenarios that would generate this result outside of the fuel.

[aussiepax]

Having seen the google earth view of where they ended up, I guess there wasn't an a/c waiting at the hold short line to take off ...... that would've also required a change of underwear seeing the 777 curve to the right towards you !

[reubee]

Interesting article on earlier 777 engine issues http://www.iasa-intl.com/folders/belfast/BA777_Unthrustworthy.htm Different engine in this example but maybe something similar

[Digger]

If it's declared a total hull loss, the insurers in most circumstances will pay out an amount close to the residual value which existed the moment before the crash, or some other agreed value which will be close to such figure. If the aircraft had smashed into smithereens by flying into a mountain or disappeared by crashing into the ocean, the pay-out on declaration of an actual total loss would be the same even though in these circumstances the scrap value would be nil. Recent insurance pay-outs have included the TAM A320 at $41m and the China 737 at $45m. Hence my estimate for this 777 of $100m minimum.

So, in this case, who then owns the wreckage, and whatever salvageable parts/scrap value there may be? The insurance company, I assume.

[reubee]

Having seen the google earth view of where they ended up, I guess there wasn't an a/c waiting at the hold short line to take off ...... that would've also required a change of underwear seeing the 777 curve to the right towards you !

just the BA aircraft leaving terminal 4 looking to cross 27L to get to 27R for take-off, and as luck would have it, one with a journalist in a prime window seat http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=508865&in_page_id=1770

[Half Bottle]

Interesting article on earlier 777 engine issues http://www.iasa-intl.com/folders/belfast/BA777_Unthrustworthy.htm Different engine in this example but maybe something similar
Interesting article, reubee, thanks. Does anyone know why in these instances the FAA was concerned about the possibility of a dual failure, because, "it was software related?" I may be misunderstanding, but it sounded as though the software problem on those GE engines was in the FADEC. But with fully independent FADECs on each engine, why would they perceive a risk that they could suffer the same problem at the same time?

(Like you, I realize that this probably has nothing to do with the BA crash since we're talking RR vs. GE, but I still would like to understand this better if anyone has any thoughts).

[CockpitCat]

I would also suspect a software bug to have been the primary cause of this incident...

[Duff]

Ok I'm no aircraft engineer,

but I will take a guess on the engine/ fuel system management.

The pilot gives a command through the throttle levers which is just a potentiometer for each engine. This gives the computer a ( 0-5V ) signal . The computer then looks at all its information through its software, then sends a varying voltage signal( 0-5V through a digital to analogue convertor ) to a pulse width modulator ( PWM ) which then gives varying current ( 100mA - 600mA ) to proportional valves to open or close ( more or less fuel to the engines )

Don is that it, in a basic way???

Now from what I understand from the incident, the engines were running, just not reacting to a command from the computer or the pilot. So I'm going to say, that I imagine each engine has its own PWM, so for both of them to fail would be unlikely, however they may both probably be powered off the same power supply (24V ). Therefore, if the power supply failed to the engine PWM's then both engines would stay at idle, but they just would not react to any commands or maybe a failed digital to analogue converter card.
I would say its unlikely that its a software problem. because you would be having multiple problems and it was a 1st of this kind ( I think ).

Just thought I would have my turn at being a arm chair investigator, without any hard facts or knowledge of the 777

Duff

homeless ex AD.com member, looking for some new friends

[ils26]

Like HB says, it sounds better. Not an N-registered plane, not in US airspace, I don't know what the CAA/AIB rules are.

http://www.aaib.dft.gov.uk/reporting_an_accident/additional_information.cfm

[flyingspark]

The plane is being moved to B.A's maintenance hangers starting this morning. Looks like they are trying to keep it all in one peice..... perhaps not a write off just yet.

[Dmmoore]

Interesting article on earlier 777 engine issues http://www.iasa-intl.com/folders/belfast/BA777_Unthrustworthy.htm Different engine in this example but maybe something similar

Good article reubee, Thanks for the link.
As you reported it affects the GE-90 engine and not the RR's on the subject aircraft but software glitches must be considered.

In this case, I suspect the problem is located somewhere outside the engine mounted FADEC system. Something became "COMMON" to both engines or we have the coincidence of the Millennial.

[Dmmoore]

So, in this case, who then owns the wreckage, and whatever salvageable parts/scrap value there may be? The insurance company, I assume.

Correct. BA has first right of refusal for any salvage which may adjust the payout but the aircraft belongs to the insurance company until such time as it's sold for salvage.

[Dmmoore]

just the BA aircraft leaving terminal 4 looking to cross 27L to get to 27R for take-off, and as luck would have it, one with a journalist in a prime window seat http://www.dailymail.co.uk/pages/live/articles/news/news.html?in_article_id=508865&in_page_id=1770

A well written and informatively aviation positive article. One of the best "eye witness" reports I've read.

[Dmmoore]

Interesting article, reubee, thanks. Does anyone know why in these instances the FAA was concerned about the possibility of a dual failure, because, "it was software related?" I may be misunderstanding, but it sounded as though the software problem on those GE engines was in the FADEC. But with fully independent FADECs on each engine, why would they perceive a risk that they could suffer the same problem at the same time?

(Like you, I realize that this probably has nothing to do with the BA crash since we're talking RR vs. GE, but I still would like to understand this better if anyone has any thoughts).

The same program error exists in all systems with that software load. "IF" both engine have the same bug loaded program there is a very good chance it "could" happen to both engines. The FAA is plying it safe(er). :rolleyes:

[PIKTEAM]

So wheres the copies then?? Post them up. Dont tell me you are another one of those idiots who didnt copy the pics before handing them over?

getting them today, the police took them off me, was told if i did not hand over i coluld be arrested and I need my record clean for the job i do airside so....

they will be disreibuted by my publisist today hopefully intime for monday am p
press

ps, to the crew i do upload here as a priority (you know how many shots of mine you reject... :p) im sure this site will have them before another certain aviation site)

david

[Dmmoore]

Ok I'm no aircraft engineer,

but I will take a guess on the engine/ fuel system management.

The pilot gives a command through the throttle levers which is just a potentiometer for each engine. This gives the computer a ( 0-5V ) signal . The computer then looks at all its information through its software, then sends a varying voltage signal( 0-5V through a digital to analogue convertor ) to a pulse width modulator ( PWM ) which then gives varying current ( 100mA - 600mA ) to proportional valves to open or close ( more or less fuel to the engines )

Don is that it, in a basic way???

Basically correct. Good Job. Each system is double or triple redundant and they crosscheck each other. "IF" there was a software error, it happened in 4 to 6 systems.


Now from what I understand from the incident, the engines were running, just not reacting to a command from the computer or the pilot. So I'm going to say, that I imagine each engine has its own PWM, so for both of them to fail would be unlikely, however they may both probably be powered off the same power supply (24V ). Therefore, if the power supply failed to the engine PWM's then both engines would stay at idle, but they just would not react to any commands or maybe a failed digital to analogue converter card.
I would say its unlikely that its a software problem. because you would be having multiple problems and it was a 1st of this kind ( I think ).

Just thought I would have my turn at being a arm chair investigator, without any hard facts or knowledge of the 777

Duff

homeless ex AD.com member, looking for some new friends

We now have an eye witness (that seems creditable) reporting a fire from one engine after touch down that self extinguished before the doors were opened. That confirms (along with the preliminary report) at least one engine was running,
You are correct with the exception that the FADEC systems use fail-safe power that extends back to the cockpit throttle resolvers. A disconnect to the triple redundant cables (with different routing for each cable, three per engine) to each engine would have to occur. The logical place would be the throttle levers themselves.

Anyone remember Ernest K. Gann's book / movie, Fate is the hunter? Spilled cup of coffee!

[Duff]

Thanks Don

Yes I thought the triple redundant systems would stump me somewhere, however I imagine all three systems power supply to the electronics or electrical signal to the engine fuel proportional valves must somehow meet in one place.

Duff

[AVIATIONFASCINATION]

Correct. BA has first right of refusal for any salvage which may adjust the payout but the aircraft belongs to the insurance company until such time as it's sold for salvage.

If airplane insurance is anything like car insurance in America, They will get $100 bucks for the plane and will be required to pay the $500 deductible!

Tim :)

[Robert Hilton]

Thanks Don

Yes I thought the triple redundant systems would stump me somewhere, however I imagine all three systems power supply to the electronics or electrical signal to the engine fuel proportional valves must somehow meet in one place.

Duff
Whatever it turns out to be it will have an awful lot of "bollocks, should have thought of that before" factor.
I still don't believe it to be software, as Don rightly points out that would be one hell of a coincidence.

[HalcyonDays]

If airplane insurance is anything like car insurance in America, They will get $100 bucks for the plane and will be required to pay the $500 deductible!

Tim :)

Some airliner insurance policies can have a deductible as high as $1m.

[O_K]

We now have an eye witness (that seems creditable) reporting a fire from one engine after touch down that self extinguished before the doors were opened. That confirms (along with the preliminary report) at least one engine was running,
You are correct with the exception that the FADEC systems use fail-safe power that extends back to the cockpit throttle resolvers. A disconnect to the triple redundant cables (with different routing for each cable, three per engine) to each engine would have to occur. The logical place would be the throttle levers themselves.
Spilled cup of coffee!

I was actually thinking along those lines. I read earlier in this topic that the auto throttle moves the trottlee levers. Does that mean that the auto throttle does not send signals to the engines, but only moves throttles in the same way as the pilot? If that is the case then the enginges would be uncontrollable if the trottle sensors that send signals to the engines failed.

There are probably 2 or 3 sets of sensors in the trottles, but the would all be located in a small space. A power surge, or as you mentioned a cup of coffe could possibly take them all out at once.

[busfan]

[/size][/font]

Basically correct. Good Job. Each system is double or triple redundant and they crosscheck each other. "IF" there was a software error, it happened in 4 to 6 systems.

So, following the FSM logic through to conclusion, the only possible single point failure in the whole chain would be the hand pushing the throttle levers? My first thought was the throttle lever pots, but there would be one per engine and odds of both failing at same time are astronomical...

[3WE]

Two points:

Software/computer problem: It's a perennial debate whether you want a "hard connection" between the cockpit and "stuff", or let a computer sit inbetween. I love that "classic" photoshop where someone pasted Microsoft BSOD's into the panels on an airliner and the classic phrase "What's it doing now?"

But all that seems too simplistic to suddenly and simultaneously "choke off" two engines (even though we're struggling to come up with other possible causes)

Point 2: Voltage spikes:

Ok, I tend to trust power backup systems, but what protects systems from power surges/voltage spikes (someone else has mentioned this). Just parlor talking- say a generator goes bezerk....so you put a fuse in the line? But then you lose power....so hopefully there's a backup battery (That probably isn't how airplanes are designed, but just an example that a power spike is a bit more complex to guard against than a power failure)

Can any of the engineer types here give us some insight into how the new critical control electronics are protected from voltage spikes?

Thanx.

[ZeroAltitude]

Can any of the engineer types here give us some insight into how the new critical control electronics are protected from voltage spikes?

Thanx.I don't know what approach is taken in airliner circuitry, but on a general basis, varistors are used to limit voltage spikes: they are non-conductive below a certain voltage, above that, they become conductive, shorting out any voltage spikes.
If the spike is not a spike but an overvoltage with more than a few milliseconds duration, this short-circuit caused by a varistor will blow a fuse, and your backup battery will have to kick in.

[Duff]

Ok In not to sure of the 777 electronics, but on other machinery electronics I've dealt with, you have isolated power supplies, abit like small transformer where you have a 24VDC to 24VDC or 24Vdc to 12Vdc etc. You also have small capacitors to help keep spikes down and also varistors as Zeroaltitude pointed out . I have found that most electronics do, to a certain degree can handle more voltage. However less voltage and they struggle like hell !!!

That is where I'm coming from, a small isolated power supply instead of giving out 24VDC is only giving out, say 15VDC, this is going to cause major trouble. Its not a complete loss off voltage, but the electronics will struggle !

For e.g. ( all figures made up !! )

Full Fuel to engine

Computer sends 5V for a full fuel command to PWM ( pulse width modulator ) which in turn sends 600mA current to the proportional valves to give max fuel

Now there is a low voltage problem say only 15VDC to PWM, instead of 24VDC

Computer sends 5V for a full fuel command to PWM ( pulse width modulator ), however the PWM with a bad power suppy of 15V, then instead of sending 600mA for full throttle is only giving 200mA current to the proportional valves. What should be full fuel is now maybe 1/4 fuel supply ( if that ).

Duff

[mawheatley]

I'm still having problems with the witnesses that say the engines were 'screaming.' Taking it down to the most basic functionality of the jet engine, I don't understand how an engine can be screaming but not producing thrust.

I do understand however how that aircraft, at its extraordinarily low altitude, with both engines at least "ticking over" can give the casual observer the illusion of screaming.

I also note that it is the word 'screaming' that has been used - if they were at full throttle, and if they were producing thrust, perhaps the word would have been "roaring" or "thundering?"

(Just a thought!)

[Half Bottle]

I do understand however how that aircraft, at its extraordinarily low altitude, with both engines at least "ticking over" can give the casual observer the illusion of screaming.
That's my bet. Most folks are not used to the sound those big-boy engines would make passing overhead your car at 100 feet, even at low power.


I also note that it is the word 'screaming' that has been used - if they were at full throttle, and if they were producing thrust, perhaps the word would have been "roaring" or "thundering?"
APU, maybe? Those can be whiny-sounding at least on some aircraft. Not sure about the 777.

[Digger]

Wouldn't having coffee on short final violate "sterile cockpit" procedures?

[Half Bottle]

Wouldn't having coffee on short final violate "sterile cockpit" procedures?
I think the suggestion was that coffee spilled earlier in the flight may have caused short-circuiting on final. Of course, that's highly improbable, but so far just about every theory seems to require an on-board Infinite Improbability Drive, so who knows?

[Dmmoore]

So, following the FSM logic through to conclusion, the only possible single point failure in the whole chain would be the hand pushing the throttle levers? My first thought was the throttle lever pots, but there would be one per engine and odds of both failing at same time are astronomical...

Actually there are three pots (resolvers) on each throttle. Each operates a separate channel of the FADEC system through separate shielded cables.

The only common point (I know) for all six cables are at the throttle pedestal.

[Dmmoore]

Two points:

Software/computer problem: It's a perennial debate whether you want a "hard connection" between the cockpit and "stuff", or let a computer sit inbetween. I love that "classic" photoshop where someone pasted Microsoft BSOD's into the panels on an airliner and the classic phrase "What's it doing now?"

But all that seems too simplistic to suddenly and simultaneously "choke off" two engines (even though we're struggling to come up with other possible causes)
The BSOD would cause MANY warning flags and audible warnings. :lol:

Point 2: Voltage spikes:

Ok, I tend to trust power backup systems, but what protects systems from power surges/voltage spikes (someone else has mentioned this). Just parlor talking- say a generator goes bezerk....so you put a fuse in the line? But then you lose power....so hopefully there's a backup battery (That probably isn't how airplanes are designed, but just an example that a power spike is a bit more complex to guard against than a power failure)

Can any of the engineer types here give us some insight into how the new critical control electronics are protected from voltage spikes?

Thanx.

The power system operates through two separate power supplies (one for each engine) from the same electrical bus as the operating. #1 engine spins #1 IDG (Integrated Drive Generator) which drives #1 electrical bus. Redundant power is supplied from #1 DC bus. Emergency power is supplied by a separate and dedicated engine driven generator. Voltage is controlled through a filtered regulator system. The internals of the box voltage protection is beyond my knowledge however they are operating on three separate circuits.

[Dmmoore]

I don't know what approach is taken in airliner circuitry, but on a general basis, varistors are used to limit voltage spikes: they are non-conductive below a certain voltage, above that, they become conductive, shorting out any voltage spikes.
If the spike is not a spike but an overvoltage with more than a few milliseconds duration, this short-circuit caused by a varistor will blow a fuse, and your backup battery will have to kick in.

I'm not sure what is used inside the box but it is working on three redundant circuits to get an output.

[Dmmoore]

I'm still having problems with the witnesses that say the engines were 'screaming.' Taking it down to the most basic functionality of the jet engine, I don't understand how an engine can be screaming but not producing thrust.

I do understand however how that aircraft, at its extraordinarily low altitude, with both engines at least "ticking over" can give the casual observer the illusion of screaming.

I also note that it is the word 'screaming' that has been used - if they were at full throttle, and if they were producing thrust, perhaps the word would have been "roaring" or "thundering?"

(Just a thought!)

It's easy. Discount all eye witness testimony that does not match the facts in evidence.

Fact. The engines were NOT at high power levels, therefore the report is in error.

[BA747-436]

If anyone's interested in an official statement:

-------------------------------------------------------------------------------------

" British Airways’ aircraft recovery team is scheduled to start the move today (Sunday) of the Boeing 777 that operated flight BA038 from Beijing to Heathrow.

Specialist equipment arrived from Staffordshire early on Sunday morning. The delicate process of positioning the 200 tonne aircraft onto electronically controlled platforms under the belly of the aircraft is likely to take several hours to complete.

The aircraft will then start the 500-metre journey from the end of the southern runway to the engineering base, which is expected to take a further two hours as the team works meticulously to make sure the aircraft is moved slowly and safely to its new location.

To prepare for the move, a recovery team has been working round the clock since Thursday to stabilise and steady the aircraft and prepare it for the move.

Hydraulic jacks and air bags were used to position eight canvas strops (correct) under the belly of the hull. These are attached to two specialist cranes each capable of lifting 150 tonnes.

Once in position the aircraft will be jacked up inch by inch until it is at the right height for the three platforms to be positioned. Each wheeled platform is capable of holding 80 tonnes.

The Operations Control Incident Centre (OCIC) remains in session today to oversee the aircraft move. In addition, the number of departures from Heathrow Airport continues to be restricted as Heathrow’s southern runway is still operating at two thirds of its normal length.

The airline is planning to operate all longhaul departures from London Heathrow today and around 85 per cent of shorthaul departures as a result of the southern runway restrictions.

All flights to and from London Gatwick are expected to operate normally."

----------------------------------------------------------------------------------


Source: Undisclosed

[Flying Bear]

Seems there was some video around for a while, supposedly showing the final moments before the landing...

Was it real? Is it still around somewhere?

[Dmmoore]

If anyone's interested in an official statment:

Always interested in official statements! 8-)

Thanks.

[BA747-436]

Always interested in official statements! 8-)

Thanks.

Few and far between around here mate ;-)

[Tbun]

getting them today, the police took them off me, was told if i did not hand over i coluld be arrested and I need my record clean for the job i do airside so....

they will be disreibuted by my publisist today hopefully intime for monday am p
press

ps, to the crew i do upload here as a priority (you know how many shots of mine you reject... :p) im sure this site will have them before another certain aviation site)

david

Cool. Can't wait, obviously. :clap:

[Squawk7500]

I thought this was one of the better articles published, with some insights from a former 777 pilot. Gives a good summary and touches on a lot of the speculation we've seen here.

http://www.timesonline.co.uk/tol/news/uk/article3216746.ece

[Half Bottle]

I thought this was one of the better articles published, with some insights from a former 777 pilot. Gives a good summary and touches on a lot of the speculation we've seen here.

http://www.timesonline.co.uk/tol/news/uk/article3216746.ece
Very good article. One of the best I can remember reading by a journalist on a complex aviation subject like this. Very few errors. Very little hyperbole.

Thanks for sharing it, Squawk.

[tinymoon]

This show you how the plane was until it smashed the ground

http://video.news.sky.com/skynews/video?videoSourceID=1301400

[mawheatley]

This show you how the plane was until it smashed the ground

http://video.news.sky.com/skynews/video?videoSourceID=1301400

That's amazing.