Anti-G training of Japanese Air Self Defense Force fighter pilots

Recently developed high-performance fighter aircraft (HPF) are capable of producing high sustained +Gz (HSG) with a rapid onset rate. This G-producing capability is now beyond human physiologic G tolerance. Many techniques to raise the tolerance to HSG have been used operationally. In order to cope with HSG effectively, the Japanese Air Self Defense Force has given high-G training for certain fighter pilots since 1982. So far, 138 pilots (62 F-15 Trainees, 76 F-4 Trainees) have completed centrifuge training at our laboratory. The 1-week program consists of: physical examination and briefing on high-G stress and its protective methods on day 1; centrifuge rides in two basic patterns--a tracking performance and a simulated aerial combat maneuver (SACM)--during the period from day 2-5; and debriefing and questionnaires on day 6. Gradual onset run (GOR) relaxed tolerance is + 5.5 +/- 0.7 Gz and rapid onset run (ROR) relaxed tolerance is + 4.9 +/- 0.6 Gz (n = 126). The difference in G tolerance between F-15 and F-4 trainees was not significant in either GOR or ROR. Loss of consciousness (LOC) occurred in 18 F-15 trainees and 15 F-4 trainees during basic patterns but all F-15 trainees met the training goal and completed the SACM pattern on day 5 without LOC. More than half of the trainees developed a variety of arrhythmias, including PVC, SVPC, A-V dissociation, S-A block, and atrial fibrillation (AF). The AF case developed WPW syndrome and atrial fibrillation followed by LOC during a 4-G warm-up pattern.(ABSTRACT TRUNCATED AT 250 WORDS)     

新型综合抗荷措施的防护效果研究

目的 研究以新型囊式抗荷系统、无胸部代偿的抗荷加压呼吸及PHP动作组成的新型综合抗荷措施防护效果;探讨采用该措施进行防护时伴有的疲劳、疼痛等问题。方法 6名被试者在载人离心机上进行了5组＋Gz暴露试验,分别为：1）基础＋Gz耐力试验（relaxedtolerance）：测定被试者不使用抗荷装备,不做抗荷动作时的＋Gz耐力。2）FLH—X联合救生服配KT—X抗荷调压器试验（FLH—X＋KT—X）：测定被试者穿FLH—X联合救生服配KT—X抗荷调压器时的＋Gz耐力。3）FLH—X-I-KT—X＋PBG试验（PBG）：测定被试者穿FLH—X联合救生服配KT—X抗荷调压器,戴TK—X保护头盔、YM—X加压供氧面罩配YTQ—X氧气调节器进行抗荷加压呼吸时的＋Gz耐力。4）6．5G持续45S试验（6．5G45S）：被试者使用与第3组试验相同的抗荷装备,进行＋6．5Gz持续45S的暴露。5）9．0G持续15S试验（9．0G15S）：被试者使用与第3组试验相同的抗荷装备,做PHP动作,进行＋9．0Gz持续15S的暴露。在每次试验结束后用主观量表记录被试者疲劳及疼痛的程度。结果试验中没有发生G—LOC（G—inducedlose of consciousness）。FLH-X联合救生服配KT—X抗荷调压器的抗荷效果为2．5G;PBG的抗荷效果为1．67G;被试者均完成了6．5G持续45S及9．0G持续15S试验。试验中被试者的颈、腰、臂及手部在＋Gz暴露时均出现过疼痛。结论 新型综合抗荷措施可以满足现代高性能战斗机的高G防护需要;该措施还应在高G导致的疼痛及颈部损伤的防护方面加以改进。     

The effect of straining maneuvers on G-protection during assisted pressure breathing

INTRODUCTION: Pilots flying high-performance aircraft increase their acceleration tolerance by using straining maneuvers and anti-G suits. Recently, assisted positive pressure breathing has been added in some aircraft systems. This study assessed the effect of anti-G straining maneuvers on the G-protective properties of one such system, the AGE-39 anti-G ensemble used in the Swedish JAS 39 Gripen aircraft. METHODS: Ten subjects were studied in a centrifuge using each of the following: 1) the AGE-39 in combination with anti-G straining maneuvers (AGSM) throughout each high-G exposure (full maneuver; FM); 2) the AGE-39 in combination with AGSM only during the initial part of each high-G exposure (reduced maneuver; RM). G-tolerance was established during exposures to rapid onset rate (ROR) G profiles with plateau levels ranging from 6.5 to 9.0 G. RESULTS: Mean G-tolerance was > or = 8.8 G (range: 8.5 to > or = 9.0 G) in the RM condition and > or = 9.0 G in all subjects in the FM condition. Mean arterial pressure was 30-50 mm Hg higher (p < 0.001) in the FM than in the RM condition at any given ROR G-load. CONCLUSIONS: AGE-39 in combination with a brief period of straining provide efficient G-protection as illustrated by the finding that all subjects could tolerate 8.5 G while performing AGSM during the initial part of the high-G exposures. However, at 9.0 G, 40% of the subjects had to perform AGSM throughout the duration of the G-exposure. That arterial pressure was only 30-50 mm Hg higher in the FM than RM condition suggests that in the presence of straining maneuvers, pressure breathing makes only a minute contribution to the arterial-pressure response.     

Q-G动作与航空供氧装备的匹配性及与加压呼吸的兼容性

5名经过Q－G和L－1动作训练的健康男性被试者，在不加压、加压4kPa和6kPa三种呼吸条件下分别作Q－G和L－1两种抗G动作，记录其呼吸参数。结果表明，Q－G动作时最大呼气流速平均值为1．175～1．645L／S，最大吸气流速平均值为1．003～1．297L／S，明显低于L－1动作时，与现行航空供氧装备的性能匹配。血压和心率记录的结果表明，加压呼吸能进一步提高Q－G动作时的升血压效果，减轻疲劳。     

Physiologic validation of a short-arm centrifuge for space application.

A short-arm centrifuge (SAC) of 5-6 ft (1.5-1.8 m) radius may be useful in space to measure tolerances to acceleration (G) and to stimulate the cardiovascular system, thereby reducing cardiovascular decompensation that occurs in weightlessness. Relaxed rapid (1G/s onset rate, ROR) and gradual (0.1 G/s onset rate, GOR) G tolerances were measured on seven men using a 5-ft (1.5 m) radius centrifuge and compared with their G tolerances obtained on the 20-ft (6.1 m) radius human-use centrifuge at the Armstrong Laboratory, Brooks AFB, TX. Since the subjects were required to flex their legs to assume a squatting position on the SAC, a similar position was used on the 20 ft (6.1 m) centrifuge called feet up (FU), and compared with normal-seated +Gz tolerances (controls). The subjects tolerated the SAC exposures without any problems. ROR and GOR tolerances were as follows: control, 3.6 G and 4.2 G; FU, 4.5 G and 5.6 G; and SAC, 4.6 G and 6.4 G. We concluded that a 5-ft radius centrifuge can be used to measure G tolerances. The increases in the SAC GOR tolerances over ROR tolerances indicate that the baroreceptors were stimulated by the G, and the SAC exposure would be useful in preventing cardiovascular decompensation in microgravity.     

The characteristics and significance of intrathoracic and abdominal pressures during Qigong (Q-G) maneuvering.

In order to investigate the mechanism of raising the blood pressure by the Qigong (Q-G) maneuver, the changes of esophageal and gastric pressures were determined during this maneuver, and the data were compared with those from the L-1 maneuver. Eight subjects performed the Q-G maneuver at +1 Gz; their esophageal pressures (mean +/- S.D.) were -6.7 +/- 2.1 mm Hg in the inspiratory phase and 0.1 +/- 3.7 mm Hg in the expiratory phase; intragastric pressures (mean +/- S.D.) were 69.5 +/- 20.2 mm Hg and 63.4 +/- 22.6 mm Hg, respectively. In 22 centrifuge runs at +4.0 to 7.5 Gz and during Q-G maneuvering, 5 subjects had esophageal pressures of -9.0 +/- 3.3 mm Hg in the inspiratory phase and 1.6 +/- 7.2 mm Hg in the expiratory phase, and gastric pressures of 140.6 +/- 23.2 mm Hg and 138.7 +/- 29.5 mm Hg, respectively. The results showed that during Q-G maneuvering, even with a high-G load, the thoracic pressure remained negative or at low pressures while gastric pressures were remarkably raised. They both fluctuated little during respiration; therefore, a relatively large and constant pressure gradient between abdominal and thoracic pressures was maintained. Here lies the significant characteristic of blood pressure raising by the Q-G maneuver. It might possess theoretical significance for further study and development of anti-G maneuvers.     

A preliminary report on a new anti-G maneuver

Inspired by Traditional Chinese Medicine and Qigong, we designed a new anti-G maneuver, the Q-G Maneuver, which has proved promising. This maneuver consists of volition mobilization, stepwise tensing of leg and abdominal muscles, and maintenance of a shallow thoracic respiration throughout. It was tested on 24 pilots on the ground and 3 pilots on a centrifuge. All pilots were monitored with heart level blood pressure, oximetry, ear lobe pulse, CO2 concentration in exhaled gas, EEG and ECG; in centrifuge runs, peripheral vision was also monitored. Blood pressure was maintained at 180-240 mm Hg for more than 30 s without fatigue. On the centrifuge, the pilots tolerated a G load 2.25-3.0 G higher than without the maneuver, without any visual disturbance. Oximetry readings were 96-97%, and there was no evidence of hyperventilation. The ear lobe pulse was even enhanced during G load with the maneuver. Follow-up visits to 18 out of 24 pilots with 455 inflight applications of the maneuver showed that the maneuver is feasible and can be used effectively during high-G load.     

Anaerobic energetics of the simulated aerial combat maneuver (SACM)

The role of anaerobic metabolism in +Gz duration tolerance was measured using venous blood lactate concentrations before G exposure and after subjects had been fatigued from exposure to one of several levels of G: low (4.5 G) sustained G (LSG); high (7-9 G) sustained G (HSG); and simulated aerial combat maneuver (SACM) of 4.5/7 G levels. A mean +/- S.E. blood lactate of six subjects fatigued from LSG was 29.8 +/- 4.0 mg%. Four subjects fatigued from HSG had blood lactates of 42.4 +/- 3.2 mg%, and six had blood lactates of 46.7 +/- 7.2 mg% from the SACM. Blood lactates appeared to correlate directly (on a group basis) with maximum heart rates found during G exposures. Six subjects exposed to 8 or 9 G for 10 s or less demonstrated an anaerobic alactate capacity. These G findings were related to fatigue produced with isometric muscle contraction in physiologic studies conducted at 1 G. We concluded that anaerobic metabolism and isometric exercise physiology are directly related to duration tolerances of fatigue at all levels of +Gz.     

下体正压模拟推拉动作对＋GZ耐力的影响

目的 用单轴向离心机和下体正压模拟推拉动作,研究推拉动作对＋Ｇｚ耐力的影响。方法 ６名受试者着ＫＨ－３抗荷服充气３００ｍｍＨｇ（１ｍｍＨｇ＝０．１３３ｋＰａ）１ｍｉｎ,测定下体正压前、中、后血压（ＢＰ）、心率（ＨＲ）变化。在离心机上测基础耐力后,向抗荷服充气３００ｍｍ Ｈｇ、１ｍｉｎ放气后立即转动离心机,测松弛Ｇ耐力。结果 收缩压（ＳＢＰ）在下体正压中与下体正压前相比升高有显著性意义（Ｐ〈０．０１     

新研囊式抗荷装备的抗荷性能

目的：探讨新研制囊式抗荷装备的抗荷性能。方法：①在离心机（＋Gz增长率为1G／s）上测定了6名受试者的基础＋Gz耐力,分别采用45％、65％和90％扩大覆盖面积抗荷服（45％ECGS、65％ECGS、90％ECGS）与KT－9抗调器配套时的＋Gz耐力,确定其抗荷性能;②在离心机（＋Gz增长率为3G／s）上测定10名飞行员穿45％ECGS配KT－9抗调器、并穿代偿背心进行抗荷正压呼吸及做抗荷动作时的＋Gz耐力。结果：45％ECGS、65％ECGS和90％ECGS的抗荷性能分别为2．50、3．38和3．63G;飞行员穿45％ECGS进行抗荷正压呼吸及做抗荷动作时的＋Gz耐力可达到9G／10s。结论：新研囊式抗荷装备的抗荷性能比现役抗荷装备明显提高。     

Mathematical models for predicting G-level tolerances

The mathematical models developed in this article predict the following human G-level tolerances: 1) rapid onset relaxed (ROR); 2) gradual onset relaxed (GOR); and, 3) straining-rapid onset. Included in the model are specific functions of: 1) anti-G suit; 2) positive pressure breathing (PBG); 3) baroreceptor reflex; 4) handgrip reflex; 5) anti-G straining maneuver (AGSM) increasing intrathoracic pressures (Pi); 6) leg elevation; and, 7) reclining seatback angles < or = 55 degrees. These functions are based on sound physiologic principles. Also discussed in the development of this model, but not included in the models, were: 1) isometric muscle contraction reflex; 2) Qigong (Q-G) maneuver; and, 3) straining GOR tolerances. The straining GOR tolerance profile was calculated to be a measure of G-duration tolerance and not G-level tolerance. A maximum P of 125 mm Hg from the AGSM was used in these models that could be augmented with PBG to 185 mm Hg. G-level tolerance predictions using this model were validated with published data.     

High-G training for fighter aircrew

From 8 Jan 85 through 12 Feb 86, 741 USAF fighter aircrew from Tactical Air Command underwent high-G training at the USAF School of Aerospace Medicine, the major objectives of the training being to increase their understanding of G stress and G protection and to raise their G tolerance. The didactics centered on discussion of the G-time tolerance curve and demonstration of an effective anti-G straining maneuver (AGSM). Exposure to G stress on the USAFSAM centrifuge allowed the trainees to determine their G tolerances and to perfect and practice their AGSM. The trainees' mean relaxed and straining G tolerances on the gradual-onset run (GOR) without anti-G suit inflation were 5.2 and 8.3 G, respectively; and 41% of the trainees reached the 9.0-G run limit. All but two of the trainees completed the 8-G, 15-s rapid-onset run (ROR) with anti-G suit inflated; 94% completed the 9-G, 15-s ROR; and 93% were able to tolerate the 9-G, 10-s ROR while looking back over their left shoulder. G-induced loss of consciousness (G-LOC) occurred in 9% of the trainees, most commonly on the GOR, less often on the 9-G RORs. Motion sickness was a significant problem in less than 1% of the trainees. Critiques provided by 382 trainees revealed 73% enthusiastic or positive assessments of the training, as opposed to only 2% negative or hostile responses. We conclude that high-G training is well-tolerated by fighter aircrew and is a highly appropriate method for minimizing the potential for aircraft mishaps due to G-LOC in flight.     

新型侧管式抗荷装置与抗荷动作的综合防护性能

目的 对新型侧管式抗荷装备与抗荷动作的综合防护性能进行研究,探讨采用二者联合的方法对８Ｇ１０ｓ（增长率为２Ｇ／ｓ）高Ｇ进行防护的可行性。方法 在离心机上,＋Ｇｚ增长率为２Ｇ／ｓ,行测量９名飞行学员的基础＋Ｇｚ耐力,其中５名飞行学员采用新型侧管式抗荷服（ＮＫＨ）＋新型抗调器（ＮＫＴ）＋Ｌ－１动作（Ｌ－１）、另４名飞行学员采用新型侧管式代偿服务（ＤＮＣ）＋ＮＫＴ＋Ｌ－１,测定出其最大＋Ｇｚ耐力。结果５     

A new hydrostatic anti-G suit vs. a pneumatic anti-G system: preliminary comparison

HYPOTHESIS: A newly developed hydrostatic anti-G suit is now commercially available. The suit is said to offer a high level of protection against +Gz acceleration. However, past experience shows that it is difficult to produce a hydrostatic suit with effective high-G protection. Careful testing is, therefore, needed to verify its efficacy. METHODS: The G-protective properties of the hydrostatic anti-G suit (Libelle; L) were compared with those of a pneumatic anti-G ensemble (AGE-39) used in the Swedish JAS 39 Cripen aircraft. Three pilots were studied during vertical (+Gz) acceleration in a centrifuge using the following: 1) the L-suit with varied straining maneuvers; 2) the AGE-39 in combination with full anti-G straining maneuvers (AGSM) throughout each high-G exposure (full maneuver; FM); and 3) the AGE-39 in combination with AGSM during the initial part of each high-G exposure (reduced maneuver; RM). G-intensity tolerance was established during exposures to rapid onset rate (ROR) profiles with G-plateau levels ranging from +6.0 to +9.0 Gz. G-endurance was studied during simulated aerial combat maneuvers (SACM) consisting of 10 cycles of 5.5 to 7.5 G. RESULTS: All three pilots tolerated 9.0 G with the pneumatic system both in the RM and FM conditions; their tolerances averaged 6.3 G (range 6.0 to 7.0 G) for the L suit. Thus, during the ROR exposures only the 6.0 G profile was completed by all subjects in all three conditions. At this G-load both muscle straining (as indicated by electromyographic activity in thigh and abdomen) and heart rate were higher in the L than in the RM condition. Mean arterial pressure at eye level was higher in the FM than in the L and RM conditions. Only one subject was able to complete the SACM profile in the L condition. In the RM condition all subjects completed the SACM profile and in the FM condition two subjects completed the SACM. CONCLUSIONS: Whether the AGE-39 was used in combination with maximal AGSM throughout the duration of each high-G exposure or with AGSM only during the initial part of the high-G exposure, G-intensity tolerance was 9.0 G. While wearing the L-suit, G-tolerance was 6.3 G. Thus, under the conditions tested, the G-protection afforded by the L-suit is not adequate for use in a 9-G aircraft.     

Anti-G suit inflation rate requirements

Relaxed +Gz rapid-onset tolerances were measured on the human-use centrifuge at the USAF School of Aerospace Medicine, using male research subjects with and without inflated anti-G suits. Tolerance at 6 G.s-1 onset rates were 0.2-0.3 G lower than those measured with 1 G.s-1 onset rates, thus suggesting the existence of another relaxed G tolerance measurement called very high onset G. Baroceptor effect was considered the reason for this difference. Delays of a mean of 3.3 s in inflating the anti-G suit did not change relaxed G tolerances at 6 G.s-1 onset rates; however, with a 4.2-s mean delay, light-loss tolerance criteria occurred sooner during the G exposure. Tolerances to 7 G with 6 G.s-1 onset rates, during which the subjects had to perform the anti-G straining maneuver (AGSM), required a mean delay of 2.8 s in six subjects before a noticeable change in light-loss criteria occurred--a mean delay of 2.0 s resulted in no change in light-loss criteria from zero delay control inflation rates. These results clearly indicate that the inflation of the anti-G suit can be delayed by at least 1 s without compromising anti-G suit protection.     

离心机模拟连续推拉动作训练方法研究

目的建立贴近实战化训练模式的连续推拉动作(PPM)离心机训练方法。方法调研提炼飞行训练中典型的PPM载荷参数,编制离心机模拟连续PPM曲线。16名战斗机飞行员作为志愿者,A组6名,采用-1Gz/3s→+6Gz/10s→2Gz/10s→0Gz/3s→+4.5Gz/10s→2Gz/10s→0.5Gz/3s→+5 Gz/10s连续PPM曲线,B组10名,采用-1Gz/3s→+6Gz/10s→2Gz/10s→0Gz/3s→+4.5Gz/10s→2Gz/10s→-1Gz/3s→+7Gz/5s连续PPM曲线(根据A组建议对曲线进行了改进),进行了HP动作对抗连续PPM离心机训练。志愿者在相对-Gz(小于+1Gz)暴露时采用HP动作的呼吸方式,在向+Gz转换时开始做较用力的HP动作,记录分析+Gz耐力、心率(HR)等指标的变化。结果A组6名志愿者均完成了连续PPM离心机训练,对PPM曲线提出了改进建议。B组9名志愿者采用改进的连续PPM曲线完成离心机训练。两组在相对-Gz时的HR均显著高于安静状态(P<0.05),连续PPM暴露时的HR变化趋势说明心血管调节有持续效应,其适应负荷有滞后。结论建立了高性能战斗机飞行员连续PPM离心机训练方法,模拟连续PPM曲线中不同水平-Gz与+Gz交替作用的模式更能体现实战化训练中长时间反复空战的特点,将应用于后续飞行员离心机训练。     

新的抗荷动作:HP与PHP动作抗荷效果的评价

目的：检验新的抗荷动作－－HP与PHP动作的抗荷效果。方法：HP动作由两部分构成,第1部分为全身肌肉根据＋Gz大小进行用力收缩;第2部分为2．5s 1个周期的呼吸部分,即在0．5s内以口快吸气,同时发出汉语拼音“H”,再通过半闭的双唇用力进行慢呼气2．0s,同时发出汉语拼音“P”。PHP是在抗荷正压呼吸条件下做的HP动作。测试对象为20名飞行员和10名志愿者。在离心机上测定10名飞行员采用KH－7抗荷服与HP动作的抗荷耐力,另外10名飞行员采用KH－7抗荷服与L－1动作时的抗荷耐力作对照。在离心机上测定10名志愿者采用KH－5抗荷服、抗荷正压呼吸装备和做PHP动作时的＋Gz耐力。结果：分别采用HP动作、L－1动作的两组飞行员的抗荷耐力均可达到8G10s,但采用HP动作时心率、呼吸率显著低于L－1动作（P＜0．05）。志愿者采用装备做PHP动作的抗荷耐力均达到了9G10s,且完成得比较轻松。结论：HP、PHP动作具有良好的抗荷效果,心脏负荷较小,而且飞行员易于理解、掌握,易于抗荷正压呼吸结合。     

The characteristics and theoretical basis of the Qigong maneuver.

We have made a systematic experimental study since we proposed the Qigong (Q-G) maneuver in 1986. The purpose of this article is to summarize our 5-year research project. It describes the theoretical problems of the Q-G maneuver, including the mechanism of blood pressure elevation induced by the Q-G maneuver, analysis of the maneuver elements and their respective contribution, the theory and method of muscular contraction in the Q-G maneuver, and the theory and practice of seated posture in the anti-G maneuver. We also describe the characteristics of the Q-G maneuver in five aspects.     

在高+Gz应激下人体血清睾酮和皮质醇水平的变化

目的　探讨加速度 (+Gz)应激对人体血清睾酮 (testosterone,T)和皮质醇 (cortisol,C)水平的影响 ,为飞行员高 +Gz 应激防护方法提供依据。　方法　 6名健康男性受试者分别进行抗荷代偿两用裤配抗荷调压器的抗荷效果试验、抗荷正压呼吸的抗荷效果试验、抗 9G持续 10s试验 ,测出所达到的G耐力 ,并采用放射免疫法检测 +Gz 暴露前、暴露后即刻及次日晨的血清T和C水平。　结果　①受试者 3次 +Gz 暴露所达到的 +Gz 耐力分别为 6 .2 1± 0 .4 9G、8.17± 0 .2 6G、9.0 3± 0 .10G ;② +Gz 暴露后血清T较 +Gz 暴露前有明显降低 ,C相对 +Gz 暴露前有明显升高 ;③ +Gz 暴露后次日晨血清T与C都有所恢复 ,但T高于 +Gz 暴露前水平 ,而C低于暴露前水平。　结论　 +Gz 应激对血清T和C影响显著 ,引起暂时性低T、高C ;促进T和C恢复的方法有待进一步研究。     

离心机训练矫治+Gz耐力不良的高性能战斗机飞行员

目的 矫治两名＋Ｇｚ耐力不良的高性能战斗机飞行员。方法在离心机上高＋ＧＺ负荷下训练抗荷动作（ＡＧＳＭ）和加压呼吸（ＰＢＧ）动作。结果 ＡＧＳＭ的抗荷效果提高３．０－３．２５Ｇ,加压呼吸了系统的抗荷效果提高２．７５－３．０Ｇ,综合耐力比基础耐力高４．２５－４．５Ｇ,两人均顺利通过８Ｇ１０Ｓ的ＳＡＣＭ＋ＧＺ曲线,达到训练标准。