Originally Posted by
Herod
I've been out of the loop for a while, but do these modern wonder-jets have engines that shut-down automatically? Sounds scary to me; I'm an old Luddite who would like to be able to make my own decision about engines.
There is only one scenario where we let the FADEC unilaterally shutdown the engine on Boeing aircraft: Uncontrollable High Thrust (UHT) while on the ground (TCMA). It's only active while on the ground (both radio altimeter and weight on wheels), if an engine goes to (or remains at) high power with the throttle at idle, the FADEC will shut it down.
This was done to address a specific FAA concern that UHT on the ground was catastrophic.
In flight, the FADEC will always do it's best to keep the thing running.
Edit: On further reflection, there is another scenario - overspeed (i.e. rotor speed over redline) - if the high rotor speed exceeds redline by a preset value, a separate circuit in the engine control will cut the fuel to protect the structural integrity of the engine. However this isn't applicable to the GE90 on the 777-300ER (it has a mechanical fly-ball governor that will hold N2 at redline).