Procedures - P-330

CHAPTER TWELVE

T-34C CONTACT

For instance, at 4300 lbs, flaps down, maintaining 20 units, your airspeed will be about 85 KIAS

and your stall speed about 55 KIAS. 85 KIAS - 35% of 85 = 55 KIAS. Or, for a 3500 lb.

airplane, airspeed would be about 77 KIAS and stall speed about 50 KIAS. Again, 77 KIAS -

35% of 77 = 50 KIAS.

As you can see, flying an approach at optimum AOA gives you an adequate safety margin

(approach airspeed above stall speed), while keeping your approach and landing speed low.

Procedures

AOA approaches will normally be flown after one or more touch-and-go landings.

After a touch-and-go, climb out at 90 KIAS (leave the flaps down) for full-flap AOA

or 100 KIAS (flaps up) for no-flap AOA. Climb to pattern altitude.

Your instructor will judge interval for the crosswind turn. During the turn notify

other aircraft in the pattern, if performing a full-flap AOA, that you will be

conducting an AOA approach.

Level off at pattern altitude and 100 KIAS by reducing power to 650-700 ft-lbs.

(approx. 550 ft-lbs. NF).

Approaching the upwind numbers, reduce power to 300 ftlbs. and slow to 20 units

AOA (approximately 80 KIAS FF/95 KIAS NF). If flaps are down, a deceleration to

20 units AOA is all that is required. If flaps are up, reduce power to 300 ft-lbs. and

lower the flaps (check airspeed below 120 KIAS) if performing a FF approach. Slow

to 20 units AOA. Carefully adjust power to approximately 500 ft-lbs. to maintain

pattern altitude and adjust nose attitude to maintain optimum AOA; 20 units on the

gauge and an amber donut, "O" on the indexer. Maintain 20 units and a wingtip

distance on downwind.

Perform the Landing Checklist prior to abeam position.

Abeam the intended point of landing reduce power to approximately 300 ftlbs. (275

ft-lbs. NF), lower the nose slightly to maintain 20 units and commence the turn at the

180 position. Your pattern over the ground should be the same as in previous

landings, but your airspeed will be constant at about 80 KIAS (95 KIAS NF). You

will probably need less angle of bank at the lower airspeed. Using the same angle of

bank as in a normal approach would result in too tight a turn.

During the approach, scan the AOA indexer, the intended point of landing and the

altimeter. Adjust power and attitude as necessary to maintain the proper rate of

descent and 20 units. If the green "slow" chevron ("V") lights up, your AOA is

higher than optimum and your airspeed is too slow. To correct, lower the nose

slightly. The chevron points in the direction the nose needs to go. Too low a nose

12-2 ANGLE OF ATTACK APPROACHES