To determine the necessary angle of bank for a rate 1 turn when airspeed is increased, what formula should be used?

To determine the necessary angle of bank for a rate 1 turn when airspeed is increased, the formula used is based on a specific relationship between the aircraft’s true airspeed and the angle of bank required to maintain a constant turn rate.

The correct formula accounts for the increase in true airspeed, which affects the radius of the turn and subsequently the angle of bank. As true airspeed increases, the aircraft needs a greater angle of bank to achieve the same turn rate because the centrifugal force acting on the aircraft also increases. Therefore, the formula that accurately reflects this relationship is the one that incorporates a divisor of 10 and an additive constant that provides the necessary adjustments for maintaining the rate 1 turn.

Using true airspeed divided by 10 plus a constant provides a direct correlation for calculating the bank angle. When true airspeed increases, this formula effectively scales the angle of bank to maintain a consistent rate of turn.

This method is derived from the physics of flight dynamics where the rate 1 turn—which is a standardized rate of turn (typically 3 degrees per second)—requires a precise angle of bank that varies with increasing speeds. The other options either incorrectly scale the relationship or do not effectively correlate with the physics of a constant turn rate