Air Combat Maneuvering
Background
pull the max g (the structural limit of the aircraft). In an ACM environment, cornering speed is that
airspeed at which the aircraft can attain the maximum turn rate and the minimum turn radius. Below
this speed, if you attempt to pull more g, the aircraft will buffet and stall at the aerodynamic limit; the
turn radius will increase and turn rate will decrease. Above this speed, with increased available g,
the structural limits can be exceeded, resulting in overstressing the aircraft. Also above this speed
at the maximum allowable g, the turn radius increases and the turn rate decreases at the structural
limit. Remember, the Vn diagrams show only instantaneous turn performance.
ENERGY MANAGEMENT
A good fighter pilot knows the above concepts but will never consciously dwell on them in the
cockpit. However, he will know his cornering speed and optimum AOAs cold. Cornering speed for
the T-45A is 300 knots. The optimum AOAs for specific aspects of performance are as follows:
Energy sustaining turn
(Sustained performance)
13-14 units
Hard turn
(Optimum performance)
16-18 units
Break turn
(Instantaneous turn rate)
19-21 units
Extension/unload
(Optimum energy addition)
5-10 units
PERFORMANCE CHARACTERISTICS EXERCISE
Because you will be demanding maximum performance from your aircraft during ACM, you need to
fly the aircraft under high performance conditions to learn and feel what happens when you “push the
envelope” before you are in a real ACM exercise. The result is the performance characteristics
exercise, which demonstrates timed turns, timed accelerations, and zero-airspeed departures using
optimum AOAs. You will practice the exercise on your first ACM hop, independent of the other
aircraft. During the timed portions of the exercise, the instructor will brief you and record the times.
To initiate the exercise, the section separates and climbs to approximately 15,000 ft MSL. Once at
altitude, establish the briefed airspeed in level flight.
For timed turns, fly at 300 knots on a cardinal heading. Execute an energy sustaining turn (13-
14 units) at MRT for 180 degrees, maintaining 300 knots. The instructor will record the time. Then
reestablish the cardinal heading and execute a hard turn (17 units) at MRT for 180 degrees of turn.
To maintain 300 knots, you will have to place the nose of the aircraft below the horizon. Again the
instructor will record the time. Climb back to your start altitude and reestablish the cardinal heading.
Execute a maximum performance break turn (19-21 units) at MRT for 180 degrees, while attempting
to maintain 300 knots. Once again, place the nose below the horizon in order to maintain 300 knots.
Compare the differences in the time it took for each turn.
For timed accelerations, establish 250 knots in level flight. Upon direction from the instructor, go to
MRT and accelerate in level flight to 300 knots. Then reestablish 250 knots and as you go to MRT,
unload the aircraft to 5-10 units to arrive at 300 knots. Again compare the time difference.
Execute zero-airspeed departures the same as during the out-of-control flight syllabus.
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