@Delta558 Thanks again. The next day, I was able to select "Ready for Takeoff," and discovered that means "Eventually . . . ."
If you wait a while, all 4 engines spool up. So now at least I can get off the ground.
I'll try again later to do a cold start.
BTW, notwithstanding p. 57 of the Manual, saving a flight does NOT save the panel state. Yesterday I saved a flight at 32,000.'
When I loaded that scenario today, I was at 32,000', but no engines on, and the landing gear extended!