Is Flap down command is same as setting the flap angle to 25degrees. Recently I am reading the information related to Flap and got confused with different terminology. Trying to get relation between flap angle and Down/Up commands. On the same line I read that EGPWS uses the flap down signal, and why EGPWS need this signal.
Depending on the aircraft, flaps can be set at one of several different settings anywhere from 5° to 40° (or more, from what I understand). All of these settings are considered "down". (The exact flap angle depends on the aircraft, current weight, air temp and other factors and more than one is "appropriate" for take off or landing depending on these conditions.)
The EGPWS (Enhanced Ground Proximity Warning System) needs to know whether flaps are up or down (among other things) so that it knows if the plane is configured for landing. If you're 50' AGL and configured for landing, the EGPWS is going to assume that your intent is to land, so it won't tell you "pull up". If you're not configured for landing, but you're still 50' AGL, it's going to yell at you in an attempt to keep you from flying into the ground.