Zero Airspeed Departure

T-34C OUT-OF-CONTROL FLIGHT

CHAPTER TWO

Zero Airspeed Departure

Description: The Zero Airspeed Departure demonstrates the departure from

controlled flight associated with an unusually high pitch attitude.

General: The maneuver will be entered by the Standardization Instructor and

recovered by the IUT. The aircraft will be positioned in a vertical attitude and power

will be reduced to idle. Airspeed will decrease to zero and upon departure, the nose

will fall forward or backward depending on the exact attitude at the top of the

maneuver. Minimum entry altitude for the Zero Airspeed Departure is 8000 feet

AGL.

CAUTION

It is preferred the nose fall forward at the departure point due to the

aircraft going through fewer pitch oscillations (typically one) prior

to recovery. If the nose falls backwards, the aircraft typically goes

through 3 or more pitch oscillations before positive "G's" and

recovery are established. These oscillations neutralize the inverted

and upright pickups in the oil pump inlet, thereby causing a low

spike in oil pressure.

Procedures

Perform the Stall Checklist and Clearing turn.

ii.

Add maximum allowable power and accelerate to aerobatic cruise

(approximately 180 - 190 KIAS).

iii.

Smoothly raise the nose to the vertical (3 1/2 "G" pullup recommended).

iv.

Reference the wingtip against the horizon.

Once vertical, reduce power to idle.

vi.

Hold back stick pressure to maintain a vertical attitude until the aircraft departs

controlled flight.

CAUTION

Reverse airflow over the control surfaces will cause significant

feedback to the controls. Failure to maintain neutral controls can

result in damaged controls and control stops.

2-16 UNUSUAL ATTITUDES AND OUT-OF-CONTROL FLIGHT