Hi all, wanted to ask, when flying say a 757, for take-off, is flaps set to 15 ok, and when should I retract them, at what altitude.

Maybe a silly question, but are flaps just used to help lift-off, and of course full flaps for landing ?

Thanks again.

Tomcat61

Tomcat its not a question of altitude but speed! The flaps on most modern jets are the Fowler type (if I remember correctly), and as well as generating drag as Andrew said, they also increase the surface area of the wing, causing the air to flow over it faster, and thus generate lift. So my advice is get them up ASAP after you've got clear of the stalling speed.

Ozzy

The principle is the same for all in that you require a certain airspeed for a given flap position to maintain flight and vertical speed. The thing is to maintain airspeed while you reconfigure the aircraft. The object is to make the aircraft "clean" asap. I've seen some very quick flaps up,gear up transitions on a variety of aircraft. Is there a reference for the 757 you can check?

In flight sim there is more than one way of doing things.  This is one of them.  To keep it realistic it is usually 15 degrees on takeoff then while on climb out, retract them to 5 degrees.  The 5 degrees is to assist with the turns you make immediatly after take off to your heading.