Unbelievable as said many times...
I cant believe all the horse%$^ that is put on here...I mean seriously if you dont know what you are saying and no one knows everything then please go ahead and say it first...Now I am not going to speculate at all on the crash..but please some simple facts on the 777 as someone who works on it everyday..
1.B777 is a fly by wire aircraft..it is not as simple as a wire to an engine..please
SYS involved include AIMS CMCS Arinc 629 OPAS FADEC
Throttle inputs go to an AIMS(Airplane Info Mngmnt Sys..and vice versa
Engine is managed by a dual channel FADEC system. The EEC is part of this system(the heart).The EEC ctrls
Engine Systems
Starts and Autostarts
T/R operation
Power to the EEC is thru dedicated alternator via PCU(Power ctrl Unit)
The Trent 884 is growth version of the RB211 developing @84000lbs of thrust
Fuel supply to this engine from airplane fuel system thru eng fuel pump(two stage) Pump supplies fuel to Fuel Metering Unit and servo fuel for actuators.Fuel flow tx and thermocouples supplies fuel flow and temp readings to cockpit via EEC.
APU is a electric and pneumatic power source both on ground and in air.
Also has a FADEC.In Air mode APU started by loss of power to both electric buses
A cold start APU would require approx 45 sec to strt from start command to being online functionally.that is able to supple electrics and pneumatics. Dual starting sys electrics and pnuematics if air px available air starter used. APU can start upto cieling for this aircraft 43100 ft for this aircraft. It is routinely done a s a test procedure during flights. APU has a an APUC for ctrl.
Fuel SYS
One ctr and two main tanks later version has larger tanks not more .At low fuel in center tanks automatic fuel feed from main tanks, and center automatically feed wing tanks.The FQIS( fuel quantity indicating system) uses ultrasonic probes not capacitor type. Same also used to detect water!
Ans also sends maintenance alert if water detected. Low fuel quantity also shows as an alert this time on EICAS and tank readout if particularly low on one.All dark panel involes all buttons and valves in for flight unless isolating for trouble.
Electrical Power
NBPT(no break power tx principle)
ELMS (Electrical Load Mngmnt Sys) This ctrls distribution of power on aircraft
Hardware includes the obvious
1 IDG 120Kva each per engine
1 Genny on the APU also 120kva
2 BUGs(backup generators) 20kva each variable freq converted to constant by backup convertor
5 TRU (Transformer rectifier unit) make dc power
1 RAT supplying 7kva
Main and APU batteries
Power sys normally operates as two independent channels Each channel one bus each bus supplied by onside genny.Apu can supply either or both with load shed coming in on overload.
Ground handling bus supplied by APU
Hot battery bus supplied by ground service bus via main and APU battery chargers
Stdby bus rcvs power from left tx bus or from stdby inverter if loss of power
BUGS are always running unless INOP and will supply pwr if main ac bus looses pwr.
BUGs not available then RAT will supply power to Flight instrument buses
ELMS GCU and BPCU montor ctrl and distributed electric power.
Now thats just an overview...just to correct some of the $%$ written here, I am sorry but by mouthing off people here are no better than those overpaid idiots on TV who then mouth your words.
The informed people here who have held off judgement before final analysis is available bravo.... but one thing I was told through school would be that no one thing can bring down an aircraft its always a chain of events not immediately visible to general eye. Crash scene footage or the way certain items are after the fact can say or do nothing this isnt CSI lol!!!
If any facts above are untrue please do correct me.
Thanks