drift down very useful in the engine out over terrain scenario.
On the a320,IF one loses an engine over the mtns ,select Max Continuous on the good engine (disconnect the Auto Thrust to retain MCT).Slow to drifdown speed,and select the alt (about FL230).It will take you about an hour to reach that level,at a Driftdown rate of about 300'per min-at a TAS of about 420.
This gives one lots o'time to consider the options(Diversion)
Cheers
