Fighter Combat - Tactics and Maneuvering

414 APPENDIX
Figure A-20. Variations in Roll Rate with Airspeed
In air combat, continuous rolls of more than 180° are seldom required.
Because a certain length of time is necessary to accelerate the roll rate from
zero to its maximum value, maximum stabilized roll rate may not be
reached during such short periods of roll. Therefore, roll acceleration is
often the controlling factor in combat performance.
In addition to roll-control power, roll acceleration is a function of the
"moment of inertia" of the aircraft. This moment of inertia about the roll
axis depends on the aircraft weight and its distribution. The greater
the total weight, and the farther it is distributed away from the fuselage
axis, the greater the inertia. Large wingspan, tip-tank fuel, and wingmounted
ordnance or engines, for example, would contribute to increased
roll inertia and reduced roll acceleration. In addition, roll performance may
vary between left and right depending on the design of the aircraft. Propdriven
fighters, for instance, generally have better roll acceleration in the
direction opposite to that of prop rotation because of engine torque effects.
Cockpit configuration may also be a factor, particularly with unboosted
control systems at high speeds. The pilot's ability to push the stick to the
left harder than he can pull it to the right may result in a noticeable
difference in roll performance.
Stabilized roll rate is also affected by wingspan. For geometrically similar
fighters, shorter wingspan results in higher stabilized roll rate for the
same speed and control deflection.
Roll performance is highly dependent on pilot technique as well as on