Dowload the Germany terrain if you don't have it.
Go to field 48
Hit the NE spawn and you will be at 20,000 feet. You need to immediately pull up the gear, get the engines on, and level the plane out without stalling. Then go practice bombing.
I've heard you can to this at field 29 by hitting the H spawn for a 30,000ft spawn.
You'll need to change to the correct country to go to those respective fields.
Ranger Bob