The first point is to understand what flaps do.
They create more wing surface area when they are extended, therefor creating more lift at slow speeds.
TAKEOFF:
Depending on the aircraft you are flying, may be a Cessna 170 or a 747, it all depends on the manufacturer of the aircraft. They may say at when you have X weight, you need no flaps but when you have a completely heavier weight, you may need flaps.
*do not use this information for real flying.
Flaps and stats increase lift for takeoff and slow you down, for landing.
They are useful for takeoff to get lift and at landing for slowing down the plane.
The flaps help to increase lift, which is essential to the landing and takeoff phase[s].
Flaps and slatsSlats and flaps
Yes, Flaps are both used to create lift (on takeoff) and to slow the aircraft (on Landing)
No. Not always. For many airplanes, it may be required if the airplane is fullly loaded.
the wing flaps go up and down
Airplane wings are designed to be most efficient when at high altitudes, traveling fast, while providing as little drag as possible. Unfortunately this design inst the best for takeoff and landing. Flaps are used to change the shape of the wing to accommodate takeoff and landing requirements. Most planes have flaps on the front of the wings (leading edge flaps) and at the back of the wings. During takeoff flaps increase lift so a plane can take off with limited runway length and lower speeds. As the plane gains speed the flaps are retracted. On approach and landing you want to fly as slow as possible so the flaps are deployed in increments till landing speed is achieved. Landing slower means less runway needed to stop.
They are quite literally called flaps, and they make the plane go up, down, left and right.
slows the plane down
They can hover and land and takeoff stright up or down
gear down, flaps down, throttle reduce, and line up with the runway.