Operating Limitations

CHAPTER TEN

T-34C CONTACT

1007. OPERATING LIMITATIONS

Aerodynamic, acceleration and aerobatic flight limitations are contained in chapter four of the

T-34C NATOPS Manual. You are required to know and operate the aircraft within these

limitations. In the event that you inadvertently overstress the aircraft, you should discontinue

aerobatics immediately and execute the IN-FLIGHT DAMAGE procedures in accordance with

NATOPS. Immediately after your return, you must "down" the plane so that the airframe can be

inspected for damage prior to the next flight.

1008. INVERTED AND ZERO G FLIGHT LIMITATIONS

The maximum inverted flight time is 15 seconds. Inverted flight above 220 KIAS is prohibited.

The maximum zero G flight time is transient.

Zero G flight is associated with a "floating" sensation. This is usually a result of relaxing too

much or all of the backstick pressure and is often referred to as "unloading the aircraft." If the

maneuvers are performed correctly, you will not experience this condition.

1009. G-INDUCED LOSS OF CONSCIOUSNESS

G-induced loss of consciousness (G-LOC) is a fainting episode caused by gravity-induced

physiological stresses on the human body. The most commonly experienced G-forces are

encountered by pilots during positive acceleration maneuvers (such as pulling out of a dive or

turning at high angles of bank). This type of positive G-force (+Gz) is directed from head to

foot, and therefore imparts a feeling of being pressed into the seat.

The ultimate effect of these forces on the human body is a tendency for blood to pool both in the

lower abdomen and the extremities. This pooling effect dramatically reduces the volume of

blood available to the eyes and brain, thereby critically reducing the oxygen available to sustain

vision and conscious brain function. The typical G-LOC sequence of progression is as follows:

Grayout -- peripheral vision is progressively impaired.

Blackout -- vision is lost completely.

Loss of consciousness.

Once G-LOC actually occurs, it typically lasts from 15-30 seconds. Once consciousness is

regained, the individual usually exhibits a period of uncontrolled muscle spasms followed by

disorientation or a "dream-like" state which can last from a few seconds to several minutes.

Some pilots have described post G-LOC feelings of detachment, apathy and temporal distortion.

Amnesia of the entire episode is a common occurrence. Impairment of piloting skills may last

for as long as 30 minutes.

Navy and Air Force investigators have identified G-LOC as a probable causal factor in numerous

Class A mishaps. The Air Force estimates that at least 12% of all Tac-Air pilots have

experienced actual G-LOC at least once. G-loading capability in the T-34C is comparable to

most tactical jets, and therefore can easily cause G-LOC among the inexperienced or unprepared

10-4 INTRODUCTION TO AEROBATICS