Libelle Self-Contained Anti-G Ensemble: Overcoming Negative Transfer
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Journal of Aviation/Aerospace Education & Research Volume 13 Number 2 JAAER Winter 2004 Article 6 Winter 2004 Libelle Self-Contained Anti-G Ensemble: Overcoming Negative Transfer Michael T. Hoepfner Marian C. Schultz [email protected] James T. Schultz [email protected] Follow this and additional works at: https://commons.erau.edu/jaaer Scholarly Commons Citation Hoepfner, M. T., Schultz, M. C., & Schultz, J. T. (2004). Libelle Self-Contained Anti-G Ensemble: Overcoming Negative Transfer. Journal of Aviation/Aerospace Education & Research, 13(2). https://doi.org/10.15394/ jaaer.2004.1555 This Article is brought to you for free and open access by the Journals at Scholarly Commons. It has been accepted for inclusion in Journal of Aviation/Aerospace Education & Research by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. Hoepfner et al.: Libelle Self-Contained Anti-G Ensemble: Overcoming Negative Trans Libelle Anti-G Ensemble LIBELLE SELF-CONTAINED ANTI-G ENSEMBLE: OVERCOMING NEGATIVE TRANSFER Michael T. Hoepfner, Marian C. Schultz, and James T. Schultz I ABSTRACT G-suits have changed over the years since Dr. Wilbur Franks invented the first anti-g suit. For the past decade the United States Air Force has been using the Combat Edge ensemble and the associated L-1 straining maneuver. The Air Force is now testing the Libelle Selfcontained Anti-G Ensemble (SAGE); it uses a unique Libelle S- Maneuver (LSM).The suit and the strahmg maneuver were determined to be valid; however, the effects of negative transfer must be addressed or it will have a sigmficant impact on the success of this program. LIBELLE SELF-CONTAINED ANTI-G more powerful, and much more maneuverable. As a result, ENSEMBLE: OVERCOMING NEGATIVE during World War I1 these "blackouts" became more TRANSFER numerous and severe in nature. German "Stuka" dive- There is a revolution occurring in the fighter bomber pilots reported losing consciousness; while at the pilot community. There are fighter pilots flying sorties in same time there was an increase in unexplainable aircraft the United States, Germany, France, and Sweden without accidents. For some reason, pilots were passing out under connecting an anti-g suit to the aircraft. These are not high g loads (Dickey & Theil, 200 1). During this period the navigation training sorties, or low g intercept sorties; but study of G induced Loss Of Consciousness (G-LOC) and dogfight-Dogfights that would incapacitate an anti-g protection was born. unprotected fighter pilot. So how are these pilots able to The Physics and Physiology fight at nine g's without ever connecting an anti-g suit to Whenever any object changes direction, the force the aircraft? These pilots are flying with the Libelle G- of inertia attempts to keep that object following along the Multiplus Selfcontained Anti-G Ensemble (SAGE). The same path. In fighter aircraft, the same holds true. When Libelle anti-g suit does not require the traditional aid the aircraft is rapidly turning the pilot is pushed down in bleed air system, but rather relies on hydrostatic pressure. the seat as his body is attempting to continue along its' This suit is currently in Operational Test and Evaluation orignal path. The exact same sensation one would (OT&E) by the U.S. Air Force at the 85th Test and experience at the bottom of a roller coaster hill. This force Evaluation Squadron (TES), located at Eglin AFB, Florida. is measured in terms of the force of gravity. Sitting in a The Need for Anti-G Protection chair one experiences one times the force of gravity or one World War I saw the beginning of the dogfight. g. On the most extreme roller wasters, one could Planes would turn as quickly as possible so that they could experience momentary forces of three g's. If an individual point their machine guns at the adversary and shoot him weighed 150 pounds at one g, they would weigh 450 down before the "banditn could do the same. In some of pounds at three g's. However, in today's modem fighter these early combat reports pilots reported loss of vision or aircraft, pilots regularly sustain nine g's for sustained "blackout in the air7'as they would call it (Hess, 1999). The periods of time. A 150-pound pilot would weigh 1,350 reason for this "blackout" was unclear and remained pounds, and his 20-pound cranium would weigh 180 unmQied until World war 11. yotu~ris! All Ulis Lill~r; his 11~1is trying to pump In the twenty years following World War I, oxygenated blood (which now weighs nine times as much) aircraft became much more advanced-they were faster, up into his brain. Obviously, the heart will not be able to Page 2 1 Published by Scholarly Commons, 2004 1 Journal of Aviation/Aerospace Education & Research, Vol. 13, No. 2 [2004], Art. 6 Libelle Anti-G Ensemble - - supply as much blood at nine g's as it would at one g and buttocks. (Gawron, 1998). When the brain does not receive its As g levels increase the blood weighs more and required amount of oxygenated blood, several detriment. more. The heart has an amazing ability to increase its things begin to occur. output through rate (pulse increases) and volume (blood If the brain does not receive su£licient oxygen pressure increases), but like any muscle, it has its' limits. carrying blood, it enters into a state know as "static When these limits are exceeded, the heart is unable to hypoxia." To fighter pilots static hypoxia has varying produce enough power (blood pressure) to force the blood degrees and associated levels of danger. During the initial to flow from the lower extremities to the head. Once this stages, visual acuity begins to decrease. Pilots lose their balance of pressures is lost, blood will begin to pool in the vision in different ways. Some pilots report this loss of lower extremities (Gawron, 1998). During World War 11, vision as a dimming sensation; some as a loss of color scientists in Canada recognized the physiology of what was discrimination, while ;hers experience "tunnel vision." If occurring and began studying ways to prevent this pooling the brain continues to be deprived of oxygenated blood, of blood. They hypothesized that if they minimizing the total vision loss will ensue. This is the proverbial pooling of blood in the pilots' legs (by increasing external "blackout." During blackout, the pilot is still aware of his pressure), blood would be unable to flow excessively down surroundings. The pilot can hear, respond to radio calls, to the legs. Therefore, the blood would be forced to higher and process information; but cannot see. At the extreme levels in the body-namely the brain. The idea was to state of static hypoxia the pilot passes out. The pilot is prevent G-LOC or as a minimum, delay the onset of - completely unconscious and incapacitated. Atter blood flow symptoms (The University of Toronto led Canada's Efforts returns to the brain the pilot will begin to wake up, but will in Aviation Medicine, 2002). be confused and disoriented for a period of time ranging Evolution of the Anti-G Suit from a few seconds to almost a minute--conscious, but still Wilbur Franks, a research scientist in Canada, incapacitated in terms of aircraft control. This phenomenon noted that under high centrifiqyl forces some test tubes is known as G induced loss of consciousness, or G-LOC. would break. However, if they were first placed inside a During relatively slow g onset rates, the pilot will larger tube filled with water, the tubes would not break. He experience vision loss prior to G-LOC, and therefore will further experimented by placing mice inside water filled be able to lower the g level prior to G-LOC. However, with condoms. Mice that were inside the water filled condoms the high g onset rates of today's advanced fighter aircraft, could survive high centrifhgal forces, but the unprotected the pilot can transition to G-LOC faster than the body can mice died. He thought pilots could use these same experience the visual symptoms of impending G-LOC principles as well (The University of Toronto led Canada's (Gamn, 1998). The blood is no longer supplying the brain Efforts in Aviation Medicine, 2002). with much needed oxygen; it is pooling in the pilot's legs Page 22 JAAER, Winter 2004 https://commons.erau.edu/jaaer/vol13/iss2/6 DOI: https://doi.org/10.15394/jaaer.2004.1555 2 Hoepfner et al.: Libelle Self-Contained Anti-G Ensemble: Overcoming Negative Trans Libelle Anti4 Ensemble Figure I. Wilbur Franks with a 1950's version of the anti-g suit. Retrieved 10 July, 2002 from httv://~~~.newsandevents.utoronto.calbioskistor~27.htm. Eakrly Anti-G Suits employed this suit fir the ihst time during the Royal Navy Franks in the early 1940's applied this principle to North African amphiiious assault in 1942 (The University pilots. With assistance of the electrical engineering of Toronto led Canada's Efforts in Aviation Medicine, department at the University of Toronto, he created an 2002). The anti-g suit was born Over the years these suits outer suit filled with water called the Frank's flying suit have undergone many changes, but the function has (Leary, 2000). Figure 2 shows this suit. The &ts were remainedthe same. astounding, "...our planes performed feats of aerobatics deemed impossile without the pilots blacking-out" Pilots Published by Scholarly Commons, 2004 3 Journal of Aviation/Aerospace Education & Research, Vol. 13, No. 2 [2004], Art. 6 Libelle Anti-G Ensemble Figure 2. Wilbur Franks' first water filled anti-g suit called the Frank's flying suit.