http://w3n-a.blogspot.com/2008/12/fl...airspeeds.html

Maneuvering during slow flight demonstrates the flight characteristics
and degree of controllability of an airplane at less than cruise
speeds. The ability to determine the characteristic control responses
at the lower airspeeds appropriate to takeoffs, departures, and
landing approaches is a critical factor in stall awareness.

As airspeed decreases, control effectiveness decreases
disproportionately. For instance, there may be a certain loss of
effectiveness when the airspeed is reduced from 30 to 20 m.p.h. above
the stalling speed, but there will normally be a much greater loss as
the airspeed is further reduced to 10 m.p.h. above stalling. The
objective of maneuvering during slow flight is to develop the pilot's
sense of feel and ability to use the controls correctly, and to
improve proficiency in performing maneuvers that require slow
airspeeds.

http://w3n-a.blogspot.com/2008/12/fl...airspeeds.html