Plane Crash in India, at least 240 dead.

[HVC]

It would probably be a freak failure though...as this is the first 787 to crash in 14 years of operation. (unless there is an upgraded replacement part involved)

It was the 737 MAX that earned them their current reputation.

737 Max has been in the air for a decade, right? But only started falling out of the air recently. So I assume it's a QA thing rather than something about the plane itself. If so wouldn't the newer 787s be liable to the same issues?

[dist]

Not that I'm implying this is directly related to what happened here, but there have been reports of quality issues at the 787 Charleston plant for years. Well before the 737 Max started losing parts mid-air. Afair, most were reports of 'foreign objects' found at final inspection (where they shouldn't be any) and people inspecting their own work.

The Max has been in service since May 2017, with the first two fatal crashes occurring in October 2017 and March 2018. Obviously the MCAS accidents were of a different nature than the recent QA issues, but both strands of issues have been tied to a decline in Boeing's safety culture as its management pushed a profit-above-all-else attitude. Boeing was charged with Fraud Conspiracy in relation to the MCAS crashes.

[crazy canuck]

One theory, not yet substantiated, is that instead of retracting the landing gear (which never did come up) the copilot retracted the flaps.  The copilot was new to the job, so it might be as tragic as him pulling the wrong switch.

I described that reasoning in post #9. There is additional information now available that indicates that the Ram Air Turbine, or "RAT" was deployed, as I also mentioned in post #9. The additional info is that the better version of the vid shot of the plane flying overhead now shows something projecting from the bottom of the plane, right where the RAT would deploy. The loud noise the survivor described would be caused by the RAT deploying.

The RAT only deploys when there is no other source of power, which would mean, in this case, that both engines had failed. That would leave the mystery of how both engines could fail at the same time.

Fuel contamination could cause that, but the pilots would have detected the contamination as soon as they went to 80% thrust to start the takeoff roll. Fuel pump failure could cause that, but the plane has multiple fuel pumps, both electrical and hydraulic, with instant rollover. How could they all fail at once?

Bird strikes are out, as such an event would leave a lot of dead birds on the ground, which wasn't the case here.

So, it is increasingly looking like simultaneous multiple engine failure, which shouldn't be possible.

Thanks

[grumbler]

The latest speculation appears to be focusing on the possibility that the planes, fuel pumps all became vapor-locked. Vapor lock occurs when a pump designed to move liquids experiences the liquid turning into gas when it enters the vacuum side if the pump (decreased pressure = lower boiling point).  The gas isn't compressible enough for the pump to move, and so nothing can enter the pump (because it's filled with gas under pressure) and nothing is pumped out because the pump doesn't have the ability to create gas pressure high enough to expel the gas into the downstream piping still full of liquid.

The reason this is significant is because of the nature of jet fuel and the extreme temperatures at the airfield that day. Jet fuel is not as volatile as gasoline, but it will vaporize if the temperature is hot enough.  According the Captain Steeve, the possibility of vapor lock is so high at 47 degrees (C) that planes are prohibited from taking off if ambient temperature is that high. The temperature at flight time was 43C. But that was the temperature at the control tower.  On the tarmac, it is possible that the temperatures were even higher. Maybe enough higher to push the fuel temperature to 47C or higher.

The reason that this potential solution is attractive, IMO, is that it explains how all three pumps could fail, since that failure could be due to external, not internal, factors. If the conditions are right for one pump to become vapor-locked, they are ripe for all three to become vapor locked.  It could even be true that two became vapor locked before the plane left the ground, and then the third one shortly after takeoff.

The solution to preventing another such tragedy might be as simple as re-writing the rule on max ambient temp allowed before takeoff. With sensors installed, the rule could also change to max fuel temp allowed before takeoff.

[Jacob]

83C ambient temperature?!!?

The scenario you describe makes sense to me - as you say, it explains the simultaneous failure of the engines - but I have a hard time wrapping my head around that temperature.

Though I guess, it's not the temperature we think of when we talk about how hot a day is (which is measured in the shade), but the actual temperature of the plane that I expect had been sitting on the runway in direct sunlight?

[grumbler]

83C ambient temperature?!!?

The scenario you describe makes sense to me - as you say, it explains the simultaneous failure of the engines - but I have a hard time wrapping my head around that temperature.

Though I guess, it's not the temperature we think of when we talk about how hot a day is (which is measured in the shade), but the actual temperature of the plane that I expect had been sitting on the runway in direct sunlight?

Should have typed 43C.  Fixed.  Dunno how I brain-farted to 83.

[Jacob]

Gotcha, thanks.

Still hot.