Corner Speed

CHAPTER NINE

BASIC FIGHTER MANEUVERING (BFM) THEORY

Turn rates are further divided into:

Instantaneous turn rate: the max turn rate at any given airspeed (energy depleting).

Sustained turn rate: the max turn rate available while sustaining energy.

The fixed and variable factors begin to interrelate. G is the ratio of lift to weight. As you know,

in turns or directional changes, lift must exceed weight, and you must apply G loads greater than

one. At a constant TAS, to increase "G", you must increase AOA. Radial "G" will dictate the

turn radius and rate. Maximum instantaneous g is the maximum lift a wing may generate at a

given airspeed. Maximum instantaneous g is dependant upon the aircraft airframe capabilities.

Corner Speed

Corner speed is an important factor of maximum turn performance. Corner speed is defined as

the minimum airspeed at which the maximum allowable g can be generated. At corner speed,

the aircraft can attain its maximum turn rate. For our purposes, 280 KIAS is the T-2C corner

speed. Below this speed, if you attempt to pull more "G", the aircraft will enter buffet and stall

at its aerodynamic limit. This results in an increase in the turn radius and a decrease in the turn

rate. On the other hand, if the aircraft is maneuvered above the corner speed, the max allowable

"G" becomes the limiting factor. The excess airspeed (above corner speed) will result in a turn

radius increase and a turn rate decrease.

Knowing and flying the corner speed and the appropriate AOAs will give the fighter the most

bang for the buck: the best turn performance for the minimum amount of energy loss. These

numbers will be further detailed in the "Energy and maneuverability" section of this chapter.

Energy Management

Understanding energy and how it relates to maneuverability is an excellent starting point when

comparing fighter aircraft. Tactical maneuvering is a function of energy management while

seeking a favorable offensive firing position. Tactical management of your energy package

throughout an engagement is essential when fighting an aircraft like the T-2C with a thrust-to-

weight ratio less than one.

Total Energy

Total Energy (TE) is the combination of the aircraft's Potential Energy (PE)(function of aircraft

altitude) and Kinetic Energy (KE)(function of airspeed). TE will be referred to as your "energy

package" and will vary according to your situation.

TE = PE + KE

PE (altitude): In general, the aircraft at a higher altitude has more PE.

KE (airspeed): The aircraft with more airspeed has the higher KE.

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BASIC FIGHTER MANEUVERING (BFM) THEORY