How very topical, I was just about to write a post on the very same topic. 10 - lift, 20 - lift + drag, 30 - drag. For an idea of how much of each think back to the early lessons on use of flap and remember the lurch you get when you retract the flaps from 20 to 10 etc. I was wondering the same thing as a checklist we use says 'retract drag flap as soon as possible on the go-around, the remainder at a safe height'. What is lift flap and what is drag flap ? In this case I have decided drag flap is 30 as so much lift is generated at flaps 20 that immediate retraction would cause unacceptable sink, however on e.g. a short field takeoff, lift flap would be 10 only since 20 would cause too much drag in that case. That doesn't really help, does it ? Oh well.
Cheers DB6
[This message has been edited by DB6 (edited 04 May 2000).]