A significant milestone specific to the fighter pilot is attending the centrifuge, a dastardly little machine made famous by its amusement park portrayals in various movies.  The centrifuge is not nearly as fun to actually experience.

Much as the movies show, pilots are seat-belted into a cubicle that simulates a cockpit on the end of a long arm that spins at amazing speeds, compressing the pilots under increased gravity (G) forces.

A person sitting or standing experiences 1 G, or a force equal to gravity.  At 9 Gs (the maximum modern fighters are designed to experience), a 200 pound person feels as though they weight 1,800 pounds.  Though significant, the increased “weight” is bearable.

The more challenging aspect of G forces is that the outward forces cause a pilot’s blood to pool in his legs and feet.  The potential result is a lack of sufficient blood to the brain which causes a blackout under G, called a “G-induced Loss of Consciousness,” or G-LOC (pronounced Gee-Lock).  Aerospace physiologists do an excellent job of teaching the proper techniques and the Air Force provides anti-g equipment to wear in the form of a chap-like “g-suit.”

All fighter pilots-in-training go through the centrifuge twice.  The first time is after completing the first portion of pilot training (in the T-6) and moving on to the T-38.  There is a specific 7.5G profile each student experiences for the T-38.  The second is after finishing the T-38 and moving on to their operational airframe.  Depending to which aircraft they’ve been assigned, the new pilots will experience slight variations on their centrifuge profile.

If the pilot G-LOCs during either of those centrifuge “rides,” the ride stops.  (And everyone watches on the closed circuit tv as the pilot regains consciousness; the rush of blood back to the brain causes random muscle movements and disorientation that looks like the pilot is flailing his arms and legs, otherwise known as “the funky chicken.”)  Most often, the technicians speak with the pilot, attempt to correct any deficiencies, and try again.  However, if the pilot is unable to “pass,” that is, stay conscious, they will not progress beyond the centrifuge.  If it is the pre-T-38 ride, they will likely be transferred to T-1s and enter the heavy, rather than fighter pilot, track.  If it is post-pilot training for a specific airframe, they will lose their fighter and be re-assigned to a low-G airframe.

Future F-16 pilots are required to stay conscious under a force of 9 Gs for 10 seconds, which is admittedly no small feat.  In fact, sustaining Gs in the centrifuge is significantly more difficult than in the actual aircraft and is extremely physically demanding.  Fortunately, so long as fighter pilots stay current in their airframe–and do not have any g-related problems while operational–they are not required to return to the centrifuge.  It is a “one time good deal.”

Though sometimes the object of scorn and derision for the pain it causes its victims (both physically, for those that endure it, and emotionally for those whose career paths change as a result of it), the training and experience of the centrifuge undoubtedly save lives.  Fighter pilots fly high performance aircraft, and without the proper training, they would be more likely to G-LOC.  When a pilot G-LOCs, it may take 10 to 60 seconds to regain enough mental acuity to continue flying.  Since fighter pilots generally fly in single seat aircraft, G-LOCs frequently results in the loss of both the aircraft and pilot, since the aircraft impacts the ground before the fighter pilot finishes ‘waking up.’

There are many ‘hard tests’ that fighter pilots and military officers must endure in order to progress.  Those who desire to succeed must pay attention to their training, persevere through the challenge, learn from the experience, and then reach back and help those who will follow after them.

Adapted from Christian Fighter Pilot is not an Oxymoron.