Hello everyone,
during a recent sim session we had time to spare and tried a dual engine flameout below 10,000ft in relative vicinity to an airport. Memory items were accomplished, the checklist was read from paper as the APU started, we decided not to speed up to 270KIAS but instead to directly go in for a landing. When the APU came online though I wondered why the checklist does not even offer the possibility to start at least one engine using APU bleed air... in the debrief I brought that up, the instructor claimed that the sim didn't reflect the autostart behaviour correctly - the actual airplane would assist the start with bleed air as soon as it would be available from the APU without further switching. Re-reading FCOM/FCTM and even the AMM SDS I couldn't find any evidence of this. The AMM is clearest and basically states that the starter will only run when the start switch is in START.
Two questions:
- Does the airplane indeed behave differently than this simulator did (engines windmilled without an increase in N2 after the APU came online)
- Why does the checklist omit the possibility to use the starter? (maybe because the subsequent ENG FAIL L/R does?...
)
I know this is a very hypothetical question, a windmill start at 270 knots is usually the best course of action - but if for some reason you cannot dive down to attain 270KIAS (due to high terrain during the initial approach perhaps) there should be an alternative.
Thanks!