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higher altitudes, energy management can be practiced with
low passes down the runway in calm winds at higher energy
levels, then at the lower trim/cruise power medium energy
level, and fi nally higher to medium trim/cruise power energy
levels. Low passes over the runway fi ne tunes the student’s
skills for energy management and is an excellent exercise to
prepare students for landings.
It is important to understand that higher energy levels should
be used while maneuvering near the ground especially
in turbulent or crosswind conditions. This is discussed in
Chapter 7, Takeoff and Departure Climbs, that higher energy
is recommended as the WSC aircraft lifts off and initially
climbs out from the runway.
Higher energy is also recommended for a power on approach
where the airspeed is higher than the normal approach
speed; and the power is higher than the normal approach
power. There is still a descent rate, but the WSC aircraft has
more overall energy to handle turbulence and crosswinds.
[Figure 6-20]
6-20
Low Speed • Low Power Fast Speed • Higher Power
Relative Wind
Flightpath
Relative Wind
Flightpath
Low Kinetic Energy High Kinetic Energy
Figure 6-20. Energy management: low and high kinetic energy for level flight.
Slow Flight and Stalls
As discussed in chapter 2, the maintenance of lift and control
of an aircraft in slow fl ight requires a certain minimum
airspeed and angle of attack. This critical airspeed depends
on certain factors, such as gross weight, load factors, and
density altitude. The minimum speed below which further
controlled fl ight is impossible is called the stalling speed.
An important feature of pilot training is the development
of the ability to estimate and “feel” the margin of speed
above the stalling speed. Also, the ability to determine the
characteristic responses of the aircraft at different airspeeds
is of great importance to the pilot. The student pilot,
therefore, must develop this awareness in order to safely
avoid stalls and to operate an aircraft correctly and safely
at slow airspeeds.
As discussed in chapter 2, the nose stalls while the tips keep
fl ying. Therefore, the defi nition of stall speed of the WSC
aircraft is the speed at which the nose starts stalling. The
control bar is pushed forward and buffeting is felt on the
control bar as the root reaches the critical angle of attack.
Separation of the laminar airfl ow occurs, creating turbulence
that can be felt in the control bar. There is a loss of positive
roll control as the nose buffets and lowers as it loses lift.
Slow Flight
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 profi ciency in performing
maneuvers that require slow airspeeds.
Slow fl ight is broken down into two distinct speeds:
1. VX and the short fi eld descent speed that was discussed
earlier, and,
2. Minimum controlled airspeed, the slowest airspeed at
which the aircraft is capable of maintaining controlled
fl ight without indications of a stall—usually 2 to 3
knots above stalling speed as discussed below.
The minimum controlled airspeed maneuver demonstrates
the fl ight characteristics and degree of controllability of the
aircraft at its minimum fl ying speed. By defi nition, the term
“fl ight at minimum controllable airspeed” means a speed at
which any further increase in angle of attack or load factor
causes an immediate stall. Instruction in fl ight at minimum
controllable airspeed should be introduced at reduced power
settings with the airspeed suffi ciently above the stall to
permit maneuvering, but close enough to the stall to sense the
characteristics of fl ight at very low airspeed—sloppy control,
ragged response to control inputs, diffi culty maintaining
altitude, etc. Maneuvering at minimum controllable airspeed
should be performed using both instrument indications and
outside visual reference. It is important that pilots form the
habit of frequent reference to the fl ight instruments, especially
the airspeed indicator, while fl ying at very low airspeeds.
However, the goal is to develop a “feel” for the aircraft at
very low airspeeds to avoid inadvertent stalls and to operate
the aircraft with precision.
The objective of performing the minimum controlled airspeed
is to fl y straight and level and make shallow level turns at
minimum controlled airspeed. To begin a minimum controlled
airspeed maneuver, the WSC is fl own at trim speed straight and
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Weight-Shift Control Aircraft Flying Handbook(79)
