Air India Crash

[squerble]

I just need to labour this flaps theory point home even further. Nothing in the details is marrying up to suggest flaps retracted too early or a no flap take off.

In the civilian video:
* you can almost clearly make out slats deployed on the leading edge
* in the higher res/original version, as the video zooms on the plane, you can make out the white shape of trailing edge flaps sat further back than the surrounding wing tips
* you can hear the RAT, and make a shaky argument of seeing a few dark pixels that would tally with RAT location
* you can't hear the engines screaming as they would be 100' into the initial climb
* the (supposed, admittedly) mayday call said "loss of thrust"
* the surviving passenger said the lights went out followed by green and white lights flickering - he was sat in an exit row with the green and white emergency exit lights above him, which only light on electrical failure.

None of that happens without loss of engines and therefore electrical power. For a simultaneous dual engine failure there are very, very few possible causes.

* fuel contamination is unlikely as you'd likely have engine sputtering before, and the odds of it hitting both engines at exactly the same time are infinitesimal.
* major electrical fault is unlikely as the engines have a built-in tiny generator that powers engine control systems in an emergency and so the engines would have stayed at takeoff power.

All that's left now is:

* a major software glitch. There has been mention of the TCMA which shutdown the engines of a Japan Airlines flight as they touched down. This system should be locked out with an air/ground latch but we're talking software here so isn't infallible.
* accidental use of both fuel cutoff switches. In the same vein as accidental flap retraction theories, this would be a tragic brain fart moment.
* intentional use of both fuel cutoff switches - pilot suicide. Horrible to think of, but an extremely effective moment to do it.


Use of the fuel cutoff switches:

* cuts fuel to the engines, but they'd operate for a little moment afterwards as fuel in the lines is used up
* disconnects all engine-driven generators. This kills all electrical power and would result in a RAT deployment as well as turning on all the emergency lighting in the cabin.




Edited for spelling

 

[MOOGLEYS]

No it wouldn't. It would be recoverable in seconds if the flaps were put back in their original place. Raising flaps by one notch doesn't reduce airspeed as it reduces drag.

I don't know how people are still running with the flaps ideas. You can hear the RAT, you can't hear the engines (hence the RAT out), supposed mayday call for "loss of thrust"... everything points to dual engine failure.

Prematurely raising the flaps would cause the aircraft to sink there is not enough thrust to maintain lift if this happens especially in the conditions this aircraft was in. There would not have been enough time to re-extend the flaps and regain enough lift is what I meant. I think it’s unlikely as the flaps are retracted in stages and a dual engine failure is more likely but until the recorders are read it’s all guess work.

Mentor pilot did a good video with another pilot that explains things better.

 

[adam cool dude]

I was watching a video from Captain Steeeve last night where he was covering much of the same ground. He typically flies the 777 but apparently many of the FMC setup etc.. is the same with the 787 and he re-iterated many of the things already covered by you and others.

Namely that it's highly unlikely they either took off with incorrect flaps or no fuel as the FMC would be screaming warnings across the cockpit with Master Cautions flashing and alarms / claxons going off in the cockpit from the moment they put the power levers up to TOGA for take off.

He also mentioned the possibility of flaps being raised in error when the pilot would typically be calling for "gear up" at around 50ft or so off the ground and having achieved positive climb rate.


I personally just find it really difficult to believe that a trained First Officer (or a Captain acting as FO) would "mistakenly" sets Flaps 0, rather than raising the gear when called.

The 2 controls are rarely (if ever) located physically close to each other and typically the lever "handle" design is very different.

It just seems highly unlikely to me that such a fundamental basic error such as that would occur, It's not a task rarely handled or barely used, It's something they do routinely every single flight.

It would be akin to someone getting in their car one morning and instead of taking the handbrake off, they pop the boot release.

It could easily be done if he was thinking about flaps or getting ready for it in his mind and when called out to raise gear you hear one thing and do something else.

We have pilots who fly jets in our flying club who still make mistakes in light aircraft purely because of a lack of recency on that type.

Maybe the F/O had been on holiday for several weeks and it was his first day back or was fatigued etc from work schedule. Flying planes isn't a 9-5 job. Especially London to India will have jet lag involved.

What Captain Steve said does seem the most logical reason. Flaps put up too early. Lost lift on the wing, Max Power, wing has gone past critical angle of attack and they are in a power on stall and he cannot drop the nose to regain lift because of no altitude which is basically a no win in that situation.

You can try and put the flaps back out but whilst that does increase the lift that in turn decreases the critical angle of attack so would make things even worse.

That being said does the 787 have some sort of lockout on flaps before a certain altitude is detected although I would think that Captain Steve would have mentioned that? It does seem pretty crazy that a technologically advanced plane like a 787 doesn't have some flap lockout feature for takeoff.

 

[squerble]

It could easily be done if he was thinking about flaps or getting ready for it in his mind and when called out to raise gear you hear one thing and do something else.

We have pilots who fly jets in our flying club who still make mistakes in light aircraft purely because of a lack of recency on that type.

Maybe the F/O had been on holiday for several weeks and it was his first day back or was fatigued etc from work schedule. Flying planes isn't a 9-5 job. Especially London to India will have jet lag involved.

What Captain Steve said does seem the most logical reason. Flaps put up too early. Lost lift on the wing, Max Power, wing has gone past critical angle of attack and they are in a power on stall and he cannot drop the nose to regain lift because of no altitude which is basically a no win in that situation.

You can try and put the flaps back out but whilst that does increase the lift that in turn decreases the critical angle of attack so would make things even worse.

That being said does the 787 have some sort of lockout on flaps before a certain altitude is detected although I would think that Captain Steve would have mentioned that? It does seem pretty crazy that a technologically advanced plane like a 787 doesn't have some flap lockout feature for takeoff.

None of which explains the RAT being deployed and lack of engine noise. This is not a flaps issue.

 

[Felon]

Speaking from his hospital bed, Mr Ramesh said the lights inside the aircraft "started flickering" moments after take off.

Within five to 10 seconds, it felt like the plane was "stuck in the air", he said.

"The lights started flickering green and white...suddenly slammed into a building and exploded."

For the lights to go out before the crash, and they lost thrust - with the amount of redundancy that exists in that plane, it almost certainly has to be a technical fault.

Pilot suicide - whilst possible for me is unlikely, especially considering the last mayday was complaining of a loss of thrust, suggesting they were likely fighting the controls as the plane sank.

If it’s not a technical fault, maybe sabotage?

 

[Feek]

My dad flew jets since the 80s and 787s for 5 year before he retired. I saw him tonight and just asked what his opinion was and he just came straight back with ‘fuel pumps weren’t on’. No idea if he’s right or not but I’ll just throw that one into the overclockers speculation pot

Not a chance.

Here's my 744 at cruise, I've turned off all the fuel pumps. It's been at cruise like this for about 20 minutes with no issues. I had audible chimes when I switched them off, the CAUTION light by the MCP is lit and I have this on the EICAS but it flies perfectly. I did the same with a takeoff with all the fuel pumps off and no issues either, climb out was fine.

/edit - In fact, here's it even further. All the cross feeds off, not a pump enabled. The message changes, it still flies.

All pumps and crossheads off, mavity feed tanks to engines.

 

[esmozz]

It could easily be done if he was thinking about flaps or getting ready for it in his mind and when called out to raise gear you hear one thing and do something else.

We have pilots who fly jets in our flying club who still make mistakes in light aircraft purely because of a lack of recency on that type.

Maybe the F/O had been on holiday for several weeks and it was his first day back or was fatigued etc from work schedule. Flying planes isn't a 9-5 job. Especially London to India will have jet lag involved.

What Captain Steve said does seem the most logical reason. Flaps put up too early. Lost lift on the wing, Max Power, wing has gone past critical angle of attack and they are in a power on stall and he cannot drop the nose to regain lift because of no altitude which is basically a no win in that situation.

You can try and put the flaps back out but whilst that does increase the lift that in turn decreases the critical angle of attack so would make things even worse.

That being said does the 787 have some sort of lockout on flaps before a certain altitude is detected although I would think that Captain Steve would have mentioned that? It does seem pretty crazy that a technologically advanced plane like a 787 doesn't have some flap lockout feature for takeoff.

It's almost impossible to take-off with no flaps in a modern aircraft.

It is possible to raise the flaps inadvertently after take-off (and on the B737 at least, the procedure is to deploy back to the first stage of flaps if you do) and I think that's why it's being touted as a theory - it has happened before.

I don't think that happened in this case, the instinctive reaction of any pilot in this case is to rapidly apply full thrust. You should hear the engines at full thrust. Also - I believe the FBW system on the 787 won't allow a pilot to pitch to a stall, (unlike the example given previously with a 747, which will quite happily allow you to stall after take-off) no matter how hard you pull back it will always keep to aircraft pitch to just below that of a stall. The wings will produce lift and as full thrust is applied the aircraft flight path should shallow out - it may not be recoverable but you would see a decreasing sink rate as the aircraft descended towards to ground.

To my mind all this hinges on the deployment of the RAT - if it did deploy, its not a flap issue.

 

[esmozz]

Not a chance.

Here's my 744 at cruise, I've turned off all the fuel pumps. It's been at cruise like this for about 20 minutes with no issues. I had audible chimes when I switched them off, the CAUTION light by the MCP is lit and I have this on the EICAS but it flies perfectly. I did the same with a takeoff with all the fuel pumps off and no issues either, climb out was fine.

I would not put to much credence to a PC flight sim package perfectly modelling fuel pressures in the fuel pumps, fuel manifold and downstream to the engines accurately.

And cruise is very different to take-off, where the amount of fuel required to be supplied to the engines at take-off thrust is much greater. I personally doubt the g_ravity fed fuel supply would be sufficient to do so.

However, maybe try it in your software and see. - I can't read.

Edit- Just to add - I'm not sure how it would be possible to take-off with no fuel pumps given the number of caution lights that should be alerting you to the fact.

 

[Felon]

I did the same with a takeoff with all the fuel pumps off and no issues either, climb out was fine.

lol how the hell can you take off with no fuel pumps? Those engines pull half a ton of fuel just for the initial takeoff.

I think your sim is messed up

 

[BUDFORCE]

I don't think it'd a flap issue either.

The flaps have several stages, take off is usually the second greatest deployment, second to landing.

Depending on the aircraft there are usually several stages of flaps from take off to normal flight, and each stage takes a while to change.

Looking at the video, the plane is climbing as normal, then literally just stops.

It was have taken the flaps longer than this to go from take off to full retracted and it would have caused a more gradual loss in lift as they moved.

Plus, and I don't know the aircraft performance, but usually, once the thing is up and going, particularly at full of nearly full throttle, even if you did pull the flaps in tes you'll get loss of lift but not something that would cause it to literally fall out of the sky like that.

 

[squerble]

lol how the hell can you take off with no fuel pumps? Those engines pull half a ton of fuel just for the initial takeoff.

I think your sim is messed up

Good god man. This sim in use is the most accurate simulation of a 747-400 outside of the real aircraft or a Level-D full motion sim.

Jet engines run on suction feed if electrically-driven fuel pumps aren't running.

 

[Feek]

I would not put to much credence to a PC flight sim package perfectly modelling fuel pressures in the fuel pumps, fuel manifold and downstream to the engines accurately.

You don't know the sim then. Certified for pilot training, been in constant development for nearly 30 years.

I think your sim is messed up

See above.

Aerowinx - Introduction

Aerowinx Precision Simulator

aerowinx.com

Good god man. This sim in use is the most accurate simulation of a 747-400 outside of the real aircraft or a Level-D full motion sim.

I'm pleased someone else knows it

 

[squerble]

You don't know the sim then. Certified for pilot training, been in constant development for nearly 30 years.

I'm pleased someone else knows it

I've been fortunate enough to visit the Simfest 747 (which I'm almost sure you know about, and runs on PSX) a few times so I'm aware of just how good it is.

I also apologise for so vociferously opposing your no-flap TO/early flap retraction theories, but I'm almost certain you're wrong

 

[Feek]

It's almost impossible to take-off with no flaps in a modern aircraft.

Agreed, I've tried a few times now and each time, the results are the same. Bad. Stall speed is so high, as soon as you get airborne, you're pretty much in stall.

It is possible to raise the flaps inadvertently after take-off (and on the B737 at least, the procedure is to deploy back to the first stage of flaps if you do) and I think that's why it's being touted as a theory - it has happened before.

Now this is what I said I think has happened but I've now flown this manually a few times as well and I'm not so sure any more. It's hairy, but it is possible to work through it. If I immediately engage the AP after takeoff, the aircraft also struggles but does manage to get through and stay airborne as well.

I also apologise for so vociferously opposing your no-flap TO/early flap retraction theories, but I'm almost certain you're wrong

We all have opinions, it's fine

I think I'm done here until we hear anything official now.

 

[Penfold101]

lol how the hell can you take off with no fuel pumps? Those engines pull half a ton of fuel just for the initial takeoff.

I think your sim is messed up

These are the tank booster pumps that send fuel to the engines/gallery. The engines have their own low and high pressure gearbox driven pumps that are more than capable of supplying all the fuel required through mavity and suction.

It also allows you to despatch without all the tank pumps working - they’re usually fitted in pairs for extra redundancy.

 

[esmozz]

Good god man. This sim in use is the most accurate simulation of a 747-400 outside of the real aircraft or a Level-D full motion sim.

Jet engines run on suction feed if electrically-driven fuel pumps aren't running.

I’ve spent hundreds of hours in level D sims. They’re not a completely accurate model of a real aircraft. They only model what’s within the flight envelope. I’m not sure a level D sim would accurately model a takeoff with suction feed only since it would never be a training item and I suspect there is not sufficient real world data to support the flight model.

Suction feed would support the fuel feed to an engine in the event of a failure in cruise and even then the QRH warns of the possibility of engine flameout at high altitude due to fuel foaming. An example of something that is not modelled in a level D sim.

I suspect the same with a takeoff with no fuel pumps. A software package such as this may be used as a procedural trainer - push this button then that button etc.

But not as an accurate enough model to be able to draw the conclusions that are being drawn here.

Again, I don’t believe you could takeoff with out fuel pumps and not have either a compete loss or degradation of thrust.

 

[esmozz]

These are the tank booster pumps that send fuel to the engines/gallery. The engines have their own low and high pressure gearbox driven pumps that are more than capable of supplying all the fuel required through mavity and suction.

It also allows you to despatch without all the tank pumps working - they’re usually fitted in pairs for extra redundancy.

What aircraft can dispatch with no tank pumps working? I don’t think it would be a commercial type.

Edit: My bad.

 

[squerble]

What aircraft can dispatch with no tank pumps working? I don’t think it would be a commercial type.

He said without all the pumps working - ie, you don't need every single one, not that it could be dispatched with none working.

 

[Penfold101]

What aircraft can dispatch with no tank pumps working? I don’t think it would be a commercial type.

Edit: My bad.

He said without all the pumps working - ie, you don't need every single one, not that it could be dispatched with none working.

In fairness, you can read it both ways cos English is a fun language

 

[ubersonic]

It just seems highly unlikely to me that such a fundamental basic error such as that would occur, It's not a task rarely handled or barely used, It's something they do routinely every single flight.

It would be akin to someone getting in their car one morning and instead of taking the handbrake off, they pop the boot release.

I'm going back a bit now, but wasn't there once an incident where a British Airways crew lead by a highly experienced pilot and WW2 RAF veteran did the exact same thing and dropped their Trident into a field?

* you can almost clearly make out slats deployed on the leading edge

I agree with your post but just thought it worth asking does the 787 not have auto slats? I know Boeing are usually a bit behind Airbus but that's seems a big omission in a flagship aircraft?