The One Third Rule

T-6A CONTACT

CHAPTER THREE

306.

THE ONE THIRD RULE

In order to come out of a turn on a specific heading, you must begin the roll-out prior to that

desired heading. The amount required to lead the heading will depend on the rate of turn and the

rate you level the wings; however, a good rule of thumb is to start the roll-out one-third the

number of degrees of bank. For example, if in a 30 AOB, the roll-out would be started 10 prior

to the desired heading on the EHSI. Remember to use rudder in the direction of the roll-out

(opposite the turn) as you roll wings level to counter adverse yaw. Smoothly level the wings,

crosscheck outside visual references, scan your EADI and EHSI, and re-trim as necessary.

307.

SLIP

A slip is uncoordinated flight occurring when the aircraft slides sideways toward the center of the

turn. It is caused by an insufficient amount of rudder in relation to the amount of aileron and the

AOB used. If you roll into a turn without using coordinated rudder and aileron, or if you hold

rudder against the turn after it has been established, the aircraft slides sideways toward its center

of turn. A slip may also occur in straight and level flight if one wing is allowed to drag;

meaning, flying with one wing low, while holding the nose of the aircraft straight by the use of

the rudder pressure. In this case, the aircraft slips downward toward the earth's surface and loses

altitude.

A slip is not a dangerous maneuver. The slip is an acceptable method to safely dissipate excess

energy under certain conditions. The flight paths for a coordinated turn and a slipping turn are

depicted in Figure 3-6. Notice the position of the balance ball.

308.

SKID

A skid is uncoordinated flight occurring when the aircraft slides sideways away from the center

of a turn. If excessive pro-turn rudder pressure is maintained after the turn is established, a skid

will result. In other words, if you try to force the aircraft to turn faster without increasing AOB,

the aircraft skids sideways away from its radius of turn. A skid may also occur when you are

flying in a level flight attitude if the nose of the aircraft is permitted to move sideways along the

horizon with wings level. This condition occurs when excessive rudder pressure is applied or the

aircraft is improperly trimmed.

A skidded turn can develop into a dangerous situation when in close proximity to the ground. In

a skid, the wing on the inside of a turn is moving slower than the outside wing. Since the slower

wing develops less lift during a skid, this compounds the reduction in lift occurring on the inside

wing of a normal turn. If allowed to progress, the skid develops into a rapid and disorienting

stall of one wing and will result in out-of-control flight. The flight paths for a coordinated turn

and a skidded turn are depicted in Figure 3-5. Notice the position of the balance ball.

FUNDAMENTAL CONCEPTS

3-7