Quote:
Originally Posted by Foxcow  My ground school instructor explained that if they lost an engine at the same time, they will both reach their single engine driftdown altitude at the same time. |
Maybe for some airplanes.
For the Citation X:
Driftdown from FL350 will take 52 minutes and cover 281 nm.
Driftdown from FL310 will take 42 minutes and cover 223 nm.
Roughly 300fpm for each a/c to reach 18,500' at max weight.
Consider this: At low weight and ISA temps at FL310, we would have to climb to the SE enroute altitude.
Just for grins: It would take 27 minutes to drift down from FL490 to FL338 (SE enroute alt).
A higher aircraft may be closer to the DD IAS, but there is less wind resistance to help slow it down. To be honest, there isn't much difference in FL310 and FL350.