Posts by user "ams6110" [Posts: 9 Total up-votes: 0 Pages: 1]

Originally Posted by andihce

\xb7 It is difficult to understand a dual engine rollback. Various causes have been suggested but ruled \x93unlikely\x94 here. However, it is not possible to rule out a unicorn event, like the dual engine rollback experienced by BA 38. Leaving aside the cause, it is useful to look at the consequences.
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Originally Posted by overstress

Yet credence is given here to his recollection of a bang and green lights etc, yet his comments about THRUST increasing are ignored by the RAT theorists\x85

Originally Posted by fdr

If you are referring to loss of all boost pumps, am not aware of any engine that will not continue to run with a suction feed to the main boost pumps at low altitudes. At high altitudes, there is a chance of cavitation of the main pumps but only at very high powers, and generally not at sea level.

Originally Posted by C2H5OH

Voltage fluctuation can have very nasty effects on electronics and sensors. There is a hacking technique called "voltage glitching" which makes use of these effects to trick electronics in states they are not designed for and never supposed to be.
So I wouldn't vouch for the FADECs if there was catastrophic problem with the power distribution in the aircraft.

Originally Posted by Alty7x7

FADEC = Full-Authority Digital Engine Control

Isolation comment still applies, but 'completely' may be debatable when there are still physical connections.

Originally Posted by CloudChasing

I\x92m sure this is wrong; was looking for confirmation. I read somewhere that the 787 keeps the fuel valve open by an electric driven actuator, and closes it by spring force.

Originally Posted by MatthiasC172

I am pretty sure that with WoW and >=85 kt a throttle being pulled to idle leads to immediate max autobrake plus speed-brake/spoilers deployment. I don’t see an option there to trigger TCMA like this but happy to learn from someone with more experience.

Originally Posted by bbofh

... The generally held theory for each engine\x92s FADEC failure (due to a common software error related to a ground-air sensing failure) is not supported by the cumulative hours over many years without such a failure. So, if you then look around for another component that can shut down two engines simultaneously you end up with the fuel shut-off valves (FSOV). Why? On each engine It is fail-safed to close off fuel-feed flows by a spring that is held open by a solenoid. If that solenoid loses electrical power, the FSOV closes and the engine shuts down after a short period.

Originally Posted by GroundedSpanner

...
But there was only so much 'good' fuel in the lines. The engines sucking fuel themselves, the fuel would now be coming from the suction pickups, a different supply. A supply likely heavily water contaminated. It would take a few seconds for that contaminated fuel to actually reach the engines, but when that contaminated fuel hit, Thrust would have been significantly reduced. The EEC's would have been doing their best to maintain the thrust, firewalling the throttles would probably have little effect at that exact moment. The engines would have likely worked through that bad fuel in a shortish period of time, but a period of time that our crew did not have. A fully loaded aircraft producing less than take-off thrust, is not sustaining enough thrust for continued flight. The rest - is down to the skill of the crew in deciding exactly where to hit the ground within the very narrow range of choice they had.