JetBlue plane's mechanical meltdown sends it 'careering wildly through the skies'

[B757300]

A JetBlue plane was sent careering wildly through the skies for fours after a mechanical meltdown.

The 155 people on board the Las Vegas to New York flight were left terrified as the A320 aircraft lurched from side to side and went into steep turns after its hydraulic system failed.

Travis McGhie, a passenger on the Sunday afternoon flight, said: 'It was four hours of hell.'

Another passenger, Tom Mizer, told the New York Post: 'People were getting sick. Some people were throwing up. There were a lot of people getting nauseous.'

They said that crew members of Flight 194 'did everything they could to prevent panic', with one attendant walking down the aisles trying to reassure people.

Mr Mizer said: 'She said "Look at me, I'm smiling. If I was scared, you would know it. If I'm not scared, you don't need to be."'

Mr McGhie added that there was no screaming, but 'there were definitely people reacting out loud'.

He said: 'The plane kind of felt out of control. It wasn't able to balance itself, and the air was choppy.'

The pair, both from Brooklyn, said they realized something was wrong with the aircraft as soon as they took off from Las Vegas airport.

Mr Mizer said: 'You could hear a screeching - an obvious mechanical screeching. We were bouncing around a lot.

'People on board got a little freaked. People were upset.

'Nobody was crazy, but everyone was upset. It became a long, sort of very tense waiting game.'

A pilot soon declared an emergency and radioed air traffic controllers to tell them that they had lost two hydraulic systems.

But as the plane contained five hours' worth of fuel, and the A320 cannot dump the excess, the pilots had to circle the area until they had burned enough to land safely.

The plane landed at Las Vegas' McCarran Airport at 7.37pm where the flight had taken off.

http://www.dailymail.co.uk/news/arti...OUR-hours.html

Now, I did not create the headline. It is the same (albeit shorter) as the source of the article.

[Evan]

Originally Posted by AvHerald

The airline reported the yellow hydraulic system had been lost.

The Aviation Herald however learned on Jun 20th that the green hydraulic system had been lost followed by an overheat indication of the yellow hydraulic system prompting the crew to report the failure of two hydraulic systems. The crew actioned the relevant checklists and were able to recover the yellow hydraulic system.

The yellow system is able to pressurize the green system via a power transfer unit, assuming the green system could hold pressure.

Loss of the green system means loss of powered gear retraction/extension, the left reverser, two spoiler panels on each wing and some braking.

The green system operates the landing gear. Perhaps this is related to the "screeching sound".

Sounds terrifying.

[Gabriel]

I really don't believe that the plane was ever out of control and "wasn't able to balance itself", even if there had been only one hydraulic systrem left (which wasn't the case).

[Evan]

It sounds like they might have shut down both the yellow and green systems for a spell. I'm guessing the wild ride was due to turbulence and manual flight control.

[Vnav]

Originally Posted by Gabriel

I really don't believe that the plane was ever out of control and "wasn't able to balance itself", even if there had been only one hydraulic systrem left (which wasn't the case).

Have you ever experienced Dutch Roll when the Yaw Damper no longer works? Certainly not "out of control"....but it will get your attention.

Not saying that's what happened, but it sounds like a possibility

[Fear_of_Flying]

The words "Jet Blue" and "meltdown" seem to be associated with each other way too often.

[Gabriel]

Originally Posted by Vnav

Have you ever experienced Dutch Roll when the Yaw Damper no longer works? Certainly not "out of control"....but it will get your attention.

Not saying that's what happened, but it sounds like a possibility

Ok, point made.
Let's ask our expert in Airbus systems, Evan:
Would the yaw damper work on only one hydro system?
Also, would the plane remain in normal law?

[MCM]

If I only had one hydro system I think I'd be putting the aeroplane on the ground pretty quickly!

[TeeVee]

Originally Posted by MCM

If I only had one hydro system I think I'd be putting the aeroplane on the ground pretty quickly!

the equivalent thread on pprune has the same statements by a number of people. and of course, the airbus crowd is somewhat defending the crew's actions.

we'll see in time...

[Gabriel]

Apparently, the thing is that they had two (out of three) bad systems, but by running the corresponding abnormal/emergency procedures and checklists, they were able to get one of those systems back on-line.

It is also being argued that, with one hydro system alone (depending which one it was), while flight control itself should be not compromised, spoilers, reversers, wheel brakes, nosewheel steering and normal gear extension could be, thus landing ASAP requires a quite a deep assessment of what will work, what can not work, then calculating the landing performance, and then finding a suitable runway.

That said, if they got one of the bad hydro systems back on-line (and thus they now had two hydro systems), one can ask if an overweight landing would not still be preferred NOW that we have all brakes, spoilers, etc working rather than waiting for the "problematic" hydro system to go back off-line and then HAVE to do the overweight landing anyway after having lost those several helpful tools.

[Evan]

Originally Posted by Gabriel

Let's ask our expert in Airbus systems, Evan:
Would the yaw damper work on only one hydro system?
Also, would the plane remain in normal law?

Ahem... Short answers...

No and No.

The way the report reads, they lost the green system and then got an overheat indication from the yellow system and reported that failed as well. Whether they actually shut that system down is unclear. If they did, and were left with only the blue system, they would indeed have no yaw damper and no flaps or slats (only WTB), no reversers and only one spoiler panel for each wing. So maybe getting weight down would be necessary before landing.

AFAIK, with the yellow and green systems disabled, the pitch would be in ALTERNATE, the roll in DIRECT and (i think) the yaw in MECHANICAL. As you may recall, those mode reversions cannot be reset until the plane is on the ground, but perhaps the yaw can return to ALTERNATE with the yellow system and the yaw damper restored.

The yellow system is linked to the green system via a power transfer unit (PTU). The PTU would have activated following the green system failure (automatically when pressure in that system dropped below 500 PSI). Perhaps this caused the yellow system to overheat. We don't know the nature of the green system fault, but the two systems are quite redundant otherwise, so it would be a unlikely coincidence for both to fail independently. If the problem with the green system was pump related, they would have been able to power all the wing surfaces with the yellow system restored via the PTU even with the green system pumps disabled.

[brianw999]

...so from that Evan, could we conclude that the general media have....er....shall we say.... exceeded their knowledge base in their reporting skills ?
After all, an aircraft "careering wildly all over the sky" is a much sexier headline attention gatherer that "Airbus aircraft has hydraulic problem successfully brought under control by crew".

...but that's just little 'ole cynical me !!!

[UncleFire]

Probably a dumb question but... How is it that they can't dump fuel?

I can understand with implications noted above that they wouldn't necessarily want to land w/out certain functions, but to stay up in the air 4 hours?

With hydro systems being flaky, I'd think they'd want to address what they could, dump fuel and land as soon as practical.

EDIT: Google, as usual is my friend. I see that a320's cannot dump fuel so I guess that renders my question rather moot.

[Fear_of_Flying]

Originally Posted by MCM

If I only had one hydro system I think I'd be putting the aeroplane on the ground pretty quickly!

I felt the same way about the Qantas engine failure, although I was pretty much alone in that opinion. When something is fairly drastically wrong with an aircraft, it needs to get down asap. If there was one unlearned lesson from SwissAir, it seems to me that was it. I know people say fire is different than uncontained engine failures or lost hydraulics, but I still maintain that there's no way to know the full extent of a problem like that - what collateral damage has occurred, what caused it in the first place - and you might be on a very short timeline.

[TeeVee]

again, the pprune thread on this incident discusses the fuel dump and overweight landing issues fairly thoroughly.

[UncleFire]

Originally Posted by Fear_of_Flying

I felt the same way about the Qantas engine failure, although I was pretty much alone in that opinion. When something is fairly drastically wrong with an aircraft, it needs to get down asap. If there was one unlearned lesson from SwissAir, it seems to me that was it. I know people say fire is different than uncontained engine failures or lost hydraulics, but I still maintain that there's no way to know the full extent of a problem like that - what collateral damage has occurred, what caused it in the first place - and you might be on a very short timeline.

Alaska Airlines 261-- just sayin'

Again tho-- as was mentioned above, if there are things you wouldn't have on landing b/c of one of the systems being out then I'd think you'd want to try and resolve before landing.

[snydersnapshots]

Originally Posted by MCM

If I only had one hydro system I think I'd be putting the aeroplane on the ground pretty quickly!

No kidding. Lose one system and I might consider burning down fuel. Lose two systems and there's something bigger going on. Time to get it on the ground.

I'm not an Airbus guy, but in Boeings the electric hydraulic pumps are in the wheel wells. I'm wondering if the grinding noise they heard was an electric pump eating itself--perhaps because of the problem (lack of fluid) or perhaps the cause of the problem.

Without a fuel dump system the airplane has to be structurally able to land at max gross takeoff weight. All that should be necessary is an overweight landing inspection.

[Gabriel]

Originally Posted by snydersnapshots

No kidding. Lose one system and I might consider burning down fuel. Lose two systems and there's something bigger going on. Time to get it on the ground.

Again, they had ONE hydro failure, another hydro overtemp (don't know exactly what part), and a third hydro Ok. The overtemp was worked around so they continued with two hydro systems.

Not saying that it was necesarily wise (or the contrary), but it's not like they circled around for 3 hours with only one hydro system left.

Without a fuel dump system the airplane has to be structurally able to land at max gross takeoff weight. All that should be necessary is an overweight landing inspection.

The same applies with a fuel dump system. The FAR requirement for an MTOW landing doesn't even mention an eventual fuel dump system.

You have a cabin fire just after rotation, you come around and land. You don't go circle a few hours to burn fuel or a few minutes to dump fuel.

[Gabriel]

Interesting Airbus training video on green and yellow hydraulic systems failure.

http://www.youtube.com/watch?v=xPt0rMVbTmk

[MCM]

My point wasn't so much a criticism that they should have landed sooner - more a comment that it was unlikely that they were only operating on one hydraulic system.

Had there only been one single system functioning, I would have imagined the aircraft would have been on the ground within a few minutes.

FoF,

The A380 incident was a little different. The time taken in that scenario was the minimum time required to understand what was functioning and what wasn't functioning, and to ensure that a safe landing could in fact be made. While yes, when you don't know what is going on with an aircraft you want to be on the ground - but similarly you don't want to rush into an approach and cause problems that could have been avoided because you didn't think them through. Thats a little different from a "known" failure mode such as losing two hydraulic systems - where the crew will have a pretty good idea what they have and haven't got within a couple of minutes.

If indeed there were two systems operating (albeit one maybe a little tenuously), then hanging around near an airport before an approach is not unreasonable. Although I wouldn't have criticised them for making an overweight landing either.