Friday, March 22, 2019

Turn Pattern

1. Description. The turn pattern (TP) is a series of constant angle of bank turns while maintaining altitude and airspeed.

Turn Pattern: Clearing the Area
2. General. The TP is started in normal cruise on a cardinal heading (north, south, east, and
west). The TP consists of two 15º angle of bank turns in opposite directions for 30º of heading
change, two 30º angle of bank turns in opposite directions for 90º of heading change, and two 45º angle of bank turns in opposite directions for 180º of heading change. A smooth reversal is made going from one turn into another, eliminating a straight and level leg. (Figure 6-4). Throughout the pattern, check the area clear, check the aircraft attitude with the horizon, and then crosscheck the nose attitude with the altimeter-VSI and the angle of bank with the attitude gyro. Correct the visual attitude as necessary. Crosscheck your instruments by periodically scanning the RMI for turn progress and the airspeed for power required. Note that the absence of a wing attitude crosscheck instrument (other than the gyro) allows you to scan the RMI frequently for turn performance and thus keeps you from overshooting headings.

The 15º angle of bank turn will require little backstick pressure or additional power. For the 30º and 45º angle of bank turns, it will be necessary to raise the nose slightly to increase the angle of attack in order to compensate for the loss of vertical lift as the bank steepens. Additional power will be  equired to maintain airspeed. To avoid overshooting the rollout headings, lead the rollout heading by a number of degrees equal to one-third the angle of bank. (For a 15º angle of bank turn, lead the rollout by 5º, etc.) Strive for smooth reversals between turns.

Trim the aircraft as necessary throughout the pattern. Remember, as the reversal or rollout occurs, the nose must be lowered back to the level attitude, and since it has been trimmed "up" during the turn, the nose will require forward stick pressure to lower it. Remember to use the P.A.T. principle.

3. Procedures
Figure 6-6 Turn Pattern 

a. Establish the aircraft straight and level on a cardinal heading, base altitude, and normal cruise.
b. Clear the area. Turn for 30º of heading  change using a 15º angle of bank. Clear the area (in the other direction) then reverse the turn, leading by the one-third rule for 30º of heading change using a 15º angle of bank.
c. Clear the area. Reverse the turn leading by the one-third rule and turn for 90º of heading change using a 30º angle of bank. Maintain altitude and airspeed with power and nose attitude; retrim. Clear the area (other direction) then reverse the turn using the one-third rule for 90º of heading change using a 30º angle of bank.  Remember to adjust nose attitude as necessary to maintain airspeed and altitude while rolling through wings level.
d. Clear the area. Reverse the turn leading by the one-third rule and turn for 180º of heading change using a 45º angle of bank. Adjust power and nose attitude to maintain altitude and airspeed; trim. Clear the area (other direction) then reverse the turn leading by the one-third rule; hold slight forward stick pressure to prevent ballooning as you roll through the wings level. Reestablish the attitude to maintain altitude; turn for 180º of heading change using a 45º angle of bank.
e. Roll out on the original heading using the one-third rule and holding slight forward stick pressure to prevent ballooning.
f. Reset power to the normal cruise power setting (as required), reset attitude and retrim for straight and level.

4. Common Errors
a. Applying the control pressures too rapidly and abruptly, or using too much backstick pressure before it is actually needed. Remember the aircraft is flown through a medium-banked turn before it reaches a steeper turn.
b. Not holding the nose attitude steady. In order to determine the appropriate corrections, you must first establish a steady attitude and allow the instruments to stabilize.
c. Staring at the nose and consequently applying control corrections too late. Divide your attention. Scan your instruments, never fixating on any one instrument. Anticipate the need for additional power and nose up. Do not wait until you are low or slow.
d. Gaining altitude in reversals. Not lowering nose as the wings pass the level flight attitude, usually due to fixating on the RMI instead of scanning the horizon.
e. Not clearing the area before and during all turns.


CHAPTER SIX T-34C FLIGHT PROCEDURES

1 comment:

  1. I'm looking forward to practicing this on an upcoming flight soon.

    ReplyDelete