Air India takeoff accident

[gsxrpilot]

Failure to climb, forgot the gear, over weight??? The 737 took out the ALS and a  brick wall. Evidently they continued the flight until ordered to divert and land. On landing it was discovered that the belly of the aircraft was ripped open among other damage.

https://www.indiatoday.in/india/story/air-india-trichy-dubai-flight-damage-airport-wall-see-photos-1366717-2018-10-12

 

[Yetti]

That's some awesome marketing material for Boeing.   "Skip it off the breakwater, bash a brick wall with it and it will still fly."

[StevenL757]

1 hour ago, Yetti said:

That's some awesome marketing material for Boeing.   "Skip it off the breakwater, bash a brick wall with it and it will still fly."

Damn right. ;-)

[kortopates]

So much for being at least 35' above the departure end of the runway threshold on IFR takeoff!

Wonder what went wrong and if it was in the pre-departure planning or on the take-off roll?

Looked pretty close to near disaster. Those poor pilots must have been shaking once they saw the damage to their plane. I would have been.

[Guest]

If the belly hit the wall,  where was the gear and why didn’t it hit something?

Clarence

[Bob_Belville]

Obviously that rip did not affect the pressurization. No flaps perhaps?


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[Mooney in Oz]

9 hours ago, Bob_Belville said:

No flaps perhaps?

There would be a very loud Config Master Warning following power application if either the leading edge devices or flaps were not deployed.  

Most likely incorrect data entry into the Flight Management Computer (FMC) that automatically sets the required power settings for takeoff.  This isn't the first time this has happened leading to similar results.  An Emirates Airbus A340 did the same on takeoff out of Melbourne, Australia in 2009 as a result of incorrect data entry, except it did not hit a wall as there wasn't one to hit. It hit the approach lights.

The video footage shows a pattern of two semi circular shapes on top of the brick wall that look consistent with being struck by the landing gear.  If that is so, how fortunate the landing gear was not ripped off.  Another testament to Boeing.

The belly was probably ripped open by a vertical row of approach lights.

On 10/13/2018 at 10:54 AM, kortopates said:

Those poor pilots must have been shaking once they saw the damage to their plane. I would have been.

They also would have been shaking from knowing the high probability of losing their jobs.

[Bob_Belville]

56 minutes ago, Mooney in Oz said:

There would be a very loud Config Master Warning following power application if either the leading edge devices or flaps were not deployed.  

Most likely incorrect data entry into the Flight Management Computer (FMC) that automatically sets the required power settings for takeoff.  This isn't the first time this has happened leading to similar results.  An Emirates Airbus A340 did the same on takeoff out of Melbourne, Australia in 2009 as a result of incorrect data entry, except it did not hit a wall as there wasn't one to hit. It hit the approach lights.

 

Interesting. Full power is not always used for take off? What about pitch?

[Mooney in Oz]

38 minutes ago, Bob_Belville said:

Interesting. Full power is not always used for take off? What about pitch?

Full power is not always used for take off in modern turbo prop or jet powered aircraft for engine longevity, as the FMC calculates the power setting through crew data input.  

An out of spec pitch setting will also generate a Config Master Warning.

There is no Master Warning trigger for incorrect (underweight) data entry into the FMC.  Usually, the FO enters the data and the Captain verifies all is correct.

[Bob_Belville]

6 minutes ago, Mooney in Oz said:

Full power is not always used for take off in modern turbo prop or jet powered aircraft for engine longevity, as the FMC calculates the power setting through crew data input.  

An out of spec pitch setting will also generate a Config Master Warning.

There is no Master Warning trigger for incorrect (underweight) data entry into the FMC.  Usually, the FO enters the data and the Captain verifies all is correct.

I suppose the PIC has a hand on the throttles as backup during take off... can he/she simply push up the power to override the automation? Recognition would be too late on a relatively short runway?

[Cyril Gibb]

34 minutes ago, Mooney in Oz said:

Full power is not always used for take off in modern turbo prop or jet powered aircraft for engine longevity, as the FMC calculates the power setting through crew data input.  

An out of spec pitch setting will also generate a Config Master Warning.

There is no Master Warning trigger for incorrect (underweight) data entry into the FMC.  Usually, the FO enters the data and the Captain verifies all is correct.

I heard the same thing from an airline pilot after the Washington crash where the plane hit a bridge and then went in the river.  When I asked him why they didn’t just give it more throttle, he said it might damage the engines.  I didn’t bother to continue the discussion.

Their options seemed to be (a) damage the engines, or (b) crash and die.  Seemed like a straightforward decision to me.

[Mooney in Oz]

2 minutes ago, Bob_Belville said:

I suppose the PIC has a hand on the throttles as backup during take off... can he/she simply push up the power to override the automation? Recognition would be too late on a relatively short runway?

SOPs can vary in airlines in that not all require both pilots to have their hands on or one has his behind the thrust levers while the other pushes the levers forward during the takeoff roll.  It might only be the PIC who has his hand on the levers, which I understand more airlines are adopting these days.  The disadvantage of having a backup hand behind the levers is in the event of a rejected takeoff due to an emergency is serious finger injuries resulting from sudden and fast lever return to reverse thrust.

The PIC can override the FMC settings and push up the power to achieve max thrust, but as you say, recognition would be too late to achieve the required performance as this needs to be adopted from commencement of the takeoff roll. 

[Mooney in Oz]

48 minutes ago, Cyril Gibb said:

he said it might damage the engines.

That sounds dismissively dumb to me.

The crash you refer to Cyril, sounds like the Air Florida 737 that ended up into the Potomac River in 1982.  I believe it was snowing with lots of ice contamination that resulted in gross lack of performance.  Pushing it up to max or even exceeding max power probably would not have saved them.

Design of late series turbine engines would probably not result in disintegration in the event of over torquing the engines, however over temping to a great degree anything is possible. These days there are in built protections to help prevent this.  I assume the Air Florida 737 was a 200 series, so I am not sure what limitations or protections the engines had in those days. 

[Jerry 5TJ]

10 minutes ago, Mooney in Oz said:

That sounds dismissively dumb to me.

The crash you refer to Cyril, sounds like the Air Florida 737 that ended up into the Potomac River in 1982.  I believe it was snowing with lots of ice contamination that resulted in gross lack of performance.  Pushing it up to max power probably would not have saved them.

Design of late series turbine engines would probably not result in disintegration in the event of over torquing the engines, however over temping to a great degree anything is possible, however there are in built protections to help prevent this.  I assume the Air Florida 737 was a 200 series, so I am not sure what limitations or protections the engines had in those days. 

From the NTSB summary on the 737-222 (N62AF) 1982 crash: 

PROBABLE CAUSE: " The flight crew's failure to use engine anti-ice during ground operation and takeoff, their decision to take off with snow/ice on the airfoil surfaces of the aircraft, and the captain’s failure to reject the takeoff during the early stage when his attention was called to anomalous engine instrument readings.”

The EPR readings were in error due to probe icing.  If the crew had advanced the power levers to achieve expected fuel flow and N1 the engines would have provided normal thrust.  

Airframe ice might have caused a stall anyway but full thrust would have helped.  Likewise a rejected takeoff would have been routine.  

Perhaps they were in too much of a hurry to get out of snowy DC and back to Florida.  

 

[EricJ]

On 10/14/2018 at 6:55 AM, Cyril Gibb said:

I heard the same thing from an airline pilot after the Washington crash where the plane hit a bridge and then went in the river.  When I asked him why they didn’t just give it more throttle, he said it might damage the engines.  I didn’t bother to continue the discussion.

Their options seemed to be (a) damage the engines, or (b) crash and die.  Seemed like a straightforward decision to me.

A lot of WWII airplanes had throttle stops that were weak safety wires that could be breached in a pinch.   Many of the engines had reserve power that could be used for a little while before it would overstress things enough that an overhaul was required.   The safety wire integrity was a record of whether the reserve had been used so that the engine needed to be inspected.   The idea was to not use it unless you needed it, but if you needed it, it's there, go for it.

Yeah, I don't get the idea of not using everything at your disposal when things are going pear-shaped.

[1964-M20E]

I fly a turbine helicopter and we do not use full power for take off.  We use what is necessary to achieve the goal hover and then transition to forward flight yes this is to prolong the life of the turbine, transmission and gear boxes.  However there is more power there and available if really needed and I would not hesitate to use if if necessary.

Just like mentioned above our military pilots past and present have power reserves and when necessary use every bit available to save the crew first then worry about the aircraft.  After all we do the same in our planes.  We have more performance available maybe not in the engine but in other areas but we do not regularly use it.  We save the crew first then worry about the aircraft later.