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for landing. Thus it is not uncommon for an airplane to land In 1921, Bessie Coleman was the
with the flaps set at 40 degrees. first African-American woman to
A more sophisticated flap is the Fowler flap shown in Figure receive a pilot certificate. She
3.28. With the Fowler flap, the rear section of the wing not had to go to France to obtain
only changes angle but also moves aft. The result is both an it, since she was not allowed to
increase in camber and an increase in wing area. A bigger in the United States.
wing will divert more air and increased camber will increase
the downwash velocity. Mechanisms to operate Fowler flaps
can be quite complicated.
The maximum lift that a flap can generate is limited by the critical
angle where the flap begins to stall. This has been improved by the
introduction of slotted flaps. A single slotted flap is shown in Figure
3.29. A slotted flap extends both aft and downward, like a Fowler flap,

Fig. 3.27. Hinged flap.