Originally Posted by
biz-buz
if the engine stops for what ever reason, the standby gene keeps turning as there is a bypass gear train in the gearbox which keeps it generating.
FYI: While each generator is driven by different internal N1 gearsets, if the engine stops so do the generators as indicated above. Regardless the 2nd generator is there due to electrical failure only per the requirements.
Originally Posted by
albatross
I assume the battery would then provide power for the short duration of the speedy return to the planet’s surface.
While in theory and use on the airplane side this is possible they have yet to accept the battery as an alternate power source for IFR SE rotorcraft. But it is being discussed. As I recall the current SPIFR offerings in the AW119 have dual generators, dual hydraulics, etc. The Bell 407 GXi IFR kit has dual generators but received waivers on several systems like dual hydraulics. Supposedly each model will be at HeliExpo 2022 with each OEM making their sales pitch to their SPIFR SE STC. Will be interesting if it does catch on.