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IndustryObserver
01-21-2008, 05:41 PM
ACCIDENT INFORMATION TELEX - ACCIDENT INFORMATION TELEX

SUBJECT: IBERIA FLIGHT IB6463 ACCIDENT IN QUITO, EQUADOR
OUR REF: IBE6463 AIT Nš2 dated 17 December 2007
PREVIOUS REF : IBE IB6463 AIT Nš1 dated 12 November 2007

This AIT is an update of AIT IB6463 Nš1 regarding the A340-600 accident during landing on runway 35 at Quito, Ecuador, on the 09th of November 2007 at 17:10 local time.

The data which follows has been approved for release by the commission of investigation led by the Ecuador Investigation Authorities.

The analysis of available data, including the accident recorders (DFDR & CVR), indicates the following sequence of events.

IB6463 was approaching on ILS 35 to Quito airport. Latest reported information to the crew during the final approach were:
- wind 170/06;
- visibility 3000m;
- wet runway.

The Captain was Pilot Flying (PF).

Quito runway 35 altitude is 9198ft. The total runway length is 3120 m. The Landing Distance Available (LDA) is 3120 m. The runway is equipped with a PAPI. However this runway has an ILS displaced threshold of 510 m (remaining LDA for ILS approach is then 2610 m).

The CVR records confirm the crew intent was initially to follow the ILS until sufficient visual references were available, then to leave the Glide Slope to visually capture and follow the PAPI path and use the full runway for landing.

The approach was performed with both AP1&2 engaged in LOC and GLIDE track modes, A/THR engaged in managed speed mode. Till touchdown, A/THR maintained the VAPP. For final approach, the aircraft was configured to land (gear down, auto-brake set to HIGH, ground spoilers armed, flaps fully extended). Landing weight was 249t, Vapp 151 kt. Given the altitude and the tailwind, the True Air Speed was 181 kt and the Ground Speed 189kt.

While AP 1+2 were engaged, the aircraft remained stabilized on the LOC and GLIDE. Runway 35 was in sight just prior to minimum, DA(H) being 9850ft(652ft).

AP 1+2 were disconnected at the minimum. The PF applied nose-down stick inputs to reach the PAPI flight path. This resulted into an increased rate of descent above 1400ft/mn between 450ft and 150ft radio-altitude. The GPWS "SINK RATE" warning was triggered at 270ft radio-altitude, it was followed by transient nose-up inputs from the PF. As programed, the THS froze at 100ft, mantaining a sightly nose down position. The "SINK RATE" warning was triggered again below 50ft AGL. The A/THR comanded IDLE power, reducing the pitch up momentum.

The touch-down ocurred at about 200m after the full runway threshold (remaining distance was 2920 m).

The landing was extremely hard ( more than 3g vertical acceleration, about 19ft/sec 1100ft/mn), which lead to:
- Breakage of the lower articulation link of both Main Landing Gear (MLG);
- Abrupt derotation of both bogie beams;
- Burst at impact of all 4 MLG front wheels;
- And damage of the wiring looms of RH an LH boogie proximity sensors that are used to detect the GROUND condition hence allowing engine thrust reversers deployment.

As a consequence of the 4 MLG front wheels burst, the AUTO BRAKE function was lost.

At touchdown, engine throttles were retarded to idle thus A/THR disengaged, and the ground spoilers deployed immediately.

The thrust reversers were selected but did not deploy because the GROUND condition monitored by the Engines Control Computers was not fulfilled due to the above mentioned sensors loom damage. For the same reason, engines stayed at FLIGHT IDLE instead of GROUND IDLE.

Full manual braking was applied 5 seconds after touchdown for the whole rollout. The average deceleration achieved during this landing phase was 0.15g. It was consistent with:
- the wet condition of the runway;
- the 4 MLG front wheel tyre burst;
- the non-deployment of the engine thrust reversers.

The runway overrun occurred at 85kt in a right turn sideslip attitude resulting from right rudder pedal inputs. The aircraft finally came to a rest at about 200m from the runway end. All passengers and crew members were safely evacuated.

At this stage of the investigation, Airbus reminds operators to comply with Standard Operating Procedure to achieve stabilized approach conditions. Go-around must be initiated if the stabilized conditions are not met at defined altitudes. Airbus also reminds, that under certain conditions a G/S or a Glide Path Angle not guarantee a stabilized approach. The engagement of A/THR is fully recomended for al flight phases, regarding the Pilot as the last responsible of its correct operation and use.

procede
01-21-2008, 07:12 PM
I'm guessing this has 'pilot error' written all over it...

Half Bottle
01-21-2008, 07:19 PM
I'm still surprised that the pilots can't select ground idle and/or use the thrust reversers through some kind of manual override. I suppose it's possible such a lock-out has prevented more trouble than it has caused, but in this case it might have prevented the overrun.

Still the activity before touchdown does seem to have 'go around' written all over it.

Schorsch
01-21-2008, 07:27 PM
I'm still surprised that the pilots can't select ground idle and/or use the thrust reversers through some kind of manual override. I suppose it's possible such a lock-out has prevented more trouble than it has caused, but in this case it might have prevented the overrun.

Still the activity before touchdown does seem to have 'go around' written all over it.

You mean it would have lowered the overun speed to ... let's say ... 75kts at best. How great!
Would be interesting to know how many more Airbus aircraft we would see as burned wreckage on the side of the runways when pilots thought this landing "is still rescueable" and use manual thrust reverse while the system hasn't sensed ground condition.


Conclusion: Don't throw any aircraft with 3g or 19ft/sec on the runway. The result afterwards is crap sliding down the runway.

Half Bottle
01-21-2008, 07:37 PM
You mean it would have lowered the overun speed to ... let's say ... 75kts at best. How great!
Would be interesting to know how many more Airbus aircraft we would see as burned wreckage on the side of the runways when pilots thought this landing "is still rescueable" and use manual thrust reverse while the system hasn't sensed ground condition.
Well, yes, Schorsch that's exactly what I meant by, "prevented more trouble than it has caused."


Conclusion: Don't throw any aircraft with 3g or 19ft/sec on the runway. The result afterwards is crap sliding down the runway.
Yes, but don't forget the TAM crash, too. Pilot error (big time), but with help from the system 'logic' that kept the spoilers retracted, despite weight on wheels + full manual braking.

Dmmoore
01-21-2008, 11:05 PM
Well, yes, Schorsch that's exactly what I meant by, "prevented more trouble than it has caused."



Yes, but don't forget the TAM crash, too. Pilot error (big time), but with help from the system 'logic' that kept the spoilers retracted, despite weight on wheels + full manual braking.

I guess we could give the pilot an "I'm on the ground damn it" switch. :lol:

Gabriel
01-22-2008, 01:40 AM
I guess we could give the pilot an "I'm on the ground damn it" switch. :lol:
Don't laugh. I seriously think so.

Rabbi O'Genius
01-22-2008, 02:19 AM
Don't laugh. I seriously think so.Though such a switch would reopen the scenario of accidental T/R deployment in flight, unless you require other conditions to be satisfied to render the switch functional.......in which case you're back to square one.

reubee
01-22-2008, 06:35 AM
What about introducing a NULL value and some 3-way logic.

GROUND condition returns TRUE|FALSE|NULL instead of returning TRUE|FALSE

So in this instance, when the proximity sensors were damaged, the GROUND condition could return NULL, and other logic would cater for this value, and the engines could go to ground idle and the T/R could be deployed.

einesellesenie
01-22-2008, 06:47 AM
...Yes, but don't forget the TAM crash, too. Pilot error (big time), but with help from the system 'logic' that kept the spoilers retracted, despite weight on wheels + full manual braking.

Did we evah get to that conclusion? Not that I disagree with it...

Show me the post number... oh, wait :sad:

einesellesenie
01-22-2008, 06:54 AM
Though such a switch would reopen the scenario of accidental T/R deployment in flight, unless you require other conditions to be satisfied to render the switch functional.......in which case you're back to square one.

I recall one terrible accident caused by the early deployment but one could argue that it was the go-around decision (on a severely damaged airframe) that killed everyone ultimately.

Maybe we should settle for a "I've touched down, dammit!" switch that not only allows for the deployment of spoilers and T/R but also inhibits any GA attempt (e.g. "Stay down, mofo" inhibiter logic).

Flying Bear
01-22-2008, 05:16 PM
What about introducing a NULL value and some 3-way logic.

GROUND condition returns TRUE|FALSE|NULL instead of returning TRUE|FALSE

So in this instance, when the proximity sensors were damaged, the GROUND condition could return NULL, and other logic would cater for this value, and the engines could go to ground idle and the T/R could be deployed.

You'd still get new failure modes whereby a latent failure in the wrong place, combined with an instantaneous GROUND=NULL failure, could cause the aircraft to do things in the air it shouldn't be doing in flight (anything from rapid decompression to reverser activation).

but also inhibits any GA attempt (e.g. "Stay down, mofo" inhibiter logic).

:shock: Imagine the results of a failure in that function...

Half Bottle
01-22-2008, 05:24 PM
Did we evah get to that conclusion? Not that I disagree with it...
Did we ever get to that conclusion? Yes. Is that official? No. Is it even unanimous amongst the parlour? I don't think so as I believe at least Stuart still thinks the pilots may have idled the engines and something mechanical or electrical did not recognize their input as such.

einesellesenie
01-22-2008, 05:39 PM
Did we ever get to that conclusion? Yes. Is that official? No. Is it even unanimous amongst the parlour? I don't think so as I believe at least Stuart still thinks the pilots may have idled the engines and something mechanical or electrical did not recognize their input as such.

Ah, OK. Why don't we come up with a parlour talker seal of investigation closure? We parlour talk, present our conclusions (voted, of course) with the PTSoIC and wait for the much slower, dim-witted real world investigation to confirm it.:twisted:

I bet someone could come up with a nice logo for the report brochure...

Dmmoore
01-22-2008, 07:18 PM
On this one I've got to go Pilot Error all the way.

Slam the aircraft onto a runway so hard you fail the landing gear and what do you expect?

Should the aircraft have been built to a higher standard? That's a subject for another thread.

Optimus Prime
01-22-2008, 07:23 PM
I'm flying out of UIO tomorrow AM... I will be sure to take some pics of the plane in transition

Gabriel
01-22-2008, 08:49 PM
What's THS?
As programed, the THS froze at 100ft, mantaining a sightly nose down position.

Vinco
01-22-2008, 09:21 PM
What would be the logic against allowing pilot full control of the reverse thrust despite ground/air mode? If you're allowed rudder inputs that cause it to structurally fail why not TR?

flyboy2548m
01-23-2008, 12:21 AM
What's THS?


Trimmable Horizontal Stabilizer.

Gabriel
01-23-2008, 12:51 AM
Trimmable Horizontal Stabilizer.
Thanks Flyboy.

Now I wonder, below 100ft and after the THS froze, will the commands keep responding in the same way as the normal law was doing before (stick centered = 1G, if not centered vertical acceleration drifts from 1G proportionally to the joystick displacement)?

I know that under the normal law the aircraft response to joystick inputs is different in different scenarios, and I always felt that it would be somehow unnatural or confusing to suddenly have a different output for the same input. I'm wondering is the flare is one of those situations where the response changes and if that could have been contributory to the acident.

After all, it doesn't sound as a bad idea to change from the glide slope of the displaced ILS to the glide slope of the PAPI to save precious meters of a short and wet runway. It doesn't sound as a manouver that requires unusual ammounts of skill either. (yes I know, it violates the stabilized approach)

Shorsch?

Alessandro
02-07-2008, 11:56 PM
Well, IB still got faith in the -600, more ordered http://www.edubourse.com/finance/actualites.php?actu=36470
Wonder if they start flying again to Quito with this bird though?