The One Third Rule - P-330

T-34C CONTACT

CHAPTER FOUR

During all turns, the ailerons and rudder are used to correct minor variations just as they are in

straight-and-level flight. However, during very steep turns, considerably more back elevator

pressure and trim is required to maintain altitude than in shallow and moderate turns, and

additional power may be needed to maintain a safe airspeed. Frequently, there is a tendency for

the airplane's nose to lower, resulting in a loss of altitude.

To recover from an unintentional nose-low attitude during a steep turn, the pilot should first

reduce the angle of bank with coordinated aileron and rudder pressure. Then back elevator

pressure should be used to raise the airplane's nose to the desired pitch attitude. After

accomplishing this, the desired angle of bank can be reestablished. Attempting to raise the nose

first by increasing back elevator pressure will usually cause a tight descending spiral, and could

lead to overstressing the airplane or stall.

408.

THE ONE-THIRD RULE

Since the airplane will continue turning as long as there is any bank, the rollout must be started

before reaching the desired heading. The amount required to lead the heading will depend on the

rate of turn and the rate at which the rollout will be made; however, a good rule of thumb is to

start the rollout one-third the number of degrees of angle of bank in use. Example: If a 30 angle

of bank turn was being used, the rollout would be started 10 prior to the desired heading. As the

wings become level, the control pressures should be gradually and smoothly released so that the

controls are neutralized as the airplane assumes straight-and-level flight. As the rollout is being

completed, attention should be given to outside visual references as well as the attitude indicator

and heading indicator to determine that the wings are being leveled precisely and the turn

stopped.

409.

BALANCED FLIGHT

Balanced flight basically exists when the aircraft is neither in a slip nor a skid as it progresses

along a flight path. With respect to balanced flight, there are two principles of control

application:

Any control deflection will result in an attitude change until the control is returned to

neutral.

There is a definite aerodynamic interrelationship between the rudder and aileron to

maintain balanced flight.

For an aircraft to be in a balanced flight condition, the controls must be applied so that the

longitudinal axis lies in the plane of forward motion. The utilization of either the rudder or the

ailerons, independent of one another, will result in a condition of unbalanced flight. The "turn

and bank" indicator has a free-rolling ball, which indicates an unbalanced condition by moving

away from the center position in the direction of the slip or skid. The pilot can also recognize

this condition by an awareness of a sensation of side motion. The side motion causes a tendency

to lean in the direction of the slip or skid. This unbalanced condition can be corrected by the

proper application of the rudder, ailerons, or both.

FUNDAMENTAL FLIGHT CONCEPTS

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