hi guys
Flaps are high lift devices. There are many different types like: plain ones,split,slotted,Fowlers. All the flap types are used to increase the maximum lift coeficient for low speed flight. All flaps are applied to the trailing edge and are usually 15-25 percent of the chord. Now the deflection of a flap produces the effect of a large amount of camber added well aft on the chord. The effectiveness of the flaps on a wing configuration depend on many different factors. One of them is the amount of wing area affected by the flaps. If the wing has a low thickness any type of flap will be less effective than on a wing of greater thickness. Sweepback of the wing can cause an additional significant reduction of effectiveness.
1)Lowering the flaps requires retriming to ballance the nose down moment change.
2)The increase in drag requires a higher power setting to maintain airspeed and altitude.
3 The AOA required toproduce the same lift coeficient is less, e.g., flap extension tends to cause the airplane to "balloon".
These are the basics guys. If something is not clear I'll be happy to assist you to make it clearer.
Cheers
Johnnie