6.3. Maneuvering at Increased G Loading. During contact flying, especially during aerobatics, G loading changes constantly. To avoid gray out, blackout, or G-induced loss of consciousness (GLOC), an effective anti-G straining maneuver is essential Factors that contribute to the onset of these symptoms include total G load, onset rate, and duration. The most intense G-loading and onset can occur during maneuvering in nose-down attitudes where the rapid acceleration can lead to high G at increasing airspeeds, such as nose-low recoveries, spin recoveries, and split-S maneuvers. Physical fitness, adequate rest, and proper hydration can improve G tolerance a proper anti-G straining maneuver (AGSM) is crucial to stave off the effects of high G maneuvering. Perform a G-awareness exercise or AGSM demonstration before accomplishing any maneuver that may require 3 or more Gs. Pilots will perform the AGSM for any maneuver where approximately 4 Gs or more will be attained. (T-2)

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6.3.1. Anti-G Straining Maneuver. Accomplish the AGSM with simultaneous short, quick breaths and lower body muscle contractions by firmly contracting muscles of the legs, abdomen, and glutes. The lower body component should consist of an isometric inward squeeze of the legs and tightening of the gluteus as well as pushing the abdominal muscles out against the G-suit. In order to adequately engage the gluteus and other lower body muscles, feet should be shoulder width apart, aligned with the knees, and knees aligned with the hips. Dig heels into the ground and pull back and allow the pelvis to roll upward as the glutes tighten. Pushing off the floor or rudder pedals with the legs limits the contraction of the glutes and other lower body muscles ultimately reducing the effectiveness of the strain. Begin the breathing component with a small preparatory breath (this should not cause the chest to rise up or tighten) sealed off at the back of the throat. Air exchange should occur every 2.5 - 3.5 seconds and should be short and crisp. To correctly perform the air exchange, the air should be blocked off at the back of the throat and a phonetic “K” should be heard on the exhale. This cycle should continue through the remainder of the G exposure. As the magnitude of G increases, increase the intensity of the muscle strain. Continue to strain and simultaneously breathe approximately every 2.5 - 3.5 seconds. Think of the AGSM as a continuum. As the amount of G increases, increase the intensity of the strain and pay careful attention to proper breathing technique. Do not hold the strain too long (more than 3 seconds) without breathing as this reduces G tolerance. If gray out occurs at the onset of G forces, application of the AGSM may not eliminate the gray out. If altitude and (or) airspeed are not critical, return to 1 G flight, reapply the anti-G strain, and then continue maneuvering. Use caution not to exceed aircraft or personal G limits. See AFPAM 11-419, G Awareness for Aircrew, for more information.

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6.3.1.1. AGSM Effectiveness. It is important to start the AGSM before the onset of G forces and maintain the strain throughout the period of increased G loading. Do not use G- suit inflation or visual disturbances as a cue to initiate an AGSM. The amount of strain required varies with the amount of applied G force. An effective AGSM uses full muscle contraction and keeps constant breathing cycles. Lower G situations still require all elements of a full AGSM but at a lower level of strain intensity. Regardless of G magnitude, it is important to perform a consistent AGSM each time you anticipate or apply G. This is critical to establish and reinforce consistent habit patterns.

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6.3.1.2. AGSM Demonstration. The AGSM demonstration allows practice of the anti-G strain technique and familiarization with increased G loading in a controlled setting. The demonstration consists of a series of turns, each at a constant G level, with a break between turns for critique and rest. The maneuver is flown at gradually increasing G levels, starting at 2 Gs and increasing to 4 Gs, depending on proficiency. If, at any time, personal G- tolerance limits are approached, inform the other crewmember. The demonstration should be of sufficient duration to ensure a proper AGSM. The AGSM cycle should last from 10- 15 seconds with at least 4 to 5 breathing cycles.

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6.3.2. G-awareness Exercise. Accomplish a G-awareness exercise on sorties that include maneuvers that require or may result in 3 or more Gs.

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6.3.2.1. The G-awareness exercise should be a level or slightly descending turn, using maximum power. Begin the maneuver with sufficient airspeed to sustain 4 Gs. (For planning purposes, use a minimum of 200 KIAS) The G-onset rate should be slow and smooth, allowing sufficient time to evaluate the effectiveness of the AGSM and determine G tolerance. Increase Gs to approximately 4-5 Gs and maintain for approximately 4-5 breathing cycles in order to allow full cardiovascular response.

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6.3.2.2. If gray out begins during the demonstration, return to 1 G flight, reevaluate the strain, and then smoothly reenter the G-awareness exercise.

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6.3.2.3. If personal G tolerance is deemed insufficient for the sortie, terminate high-G maneuvering and consider terminating the mission.

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6.3.2.4. G Estimation. With a properly fitted G-suit, aircrew can use the inflation to estimate the aircraft’s G-loading. For example, at 2 Gs, the G-suit begins to inflate (clinch) the legs. At 3 Gs, the belly bladder begins to inflate. At 4 Gs, the G-suit should be fully inflated.

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6.3.2.5. Technique. PCL - MAX, Airspeed – 200-220 KIAS. Roll to approximately 70-80 degrees of bank. Attitude is between Line-on-Line and 5 degrees nose low in the Low MOA and can be as low as 10 degrees nose low in the High MOA. Approaching 70 degrees of bank gradually increase back stick pressure to sustain 4-5 Gs. During the maneuver the TAS antennas should be moving on/slightly below the horizon to maintain level flight or slight decrease in altitude.

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