Eiken Ola, Kölegärd Roger, Bergsten Eddie, Grönkvist Mikael
Swedish Defence Research Agency, Karolinska Institutet, Stockholm, Sweden.
Aviat Space Environ Med. 2007 Apr;78(4):392-8.
G protection in the 39 Gripen aircraft is provided by a full coverage anti-G suit, a pressure-breathing system, and anti-G straining maneuvers (AGSM). The purpose was to study (1) the interaction of pressure breathing and AGSM while wearing an anti-G suit; and (2) the G-protective properties of the anti-G suit alone and in combination with the pressure-breathing system.
During rapid onset rate G-time profiles (< or =9 G), 10 subjects were investigated in 5 conditions: (I) sitting relaxed, without any G-protective garment; (II) sitting relaxed and wearing an anti-G suit; (III) sitting relaxed, wearing an anti-G suit, and pressure breathing; IV) wearing an anti-G suit and performing AGSM; and V) wearing an anti-G suit, pressure breathing, and performing AGSM. In supplementary experiments (n=9), the share of the anti-G suit protection afforded by the abdominal bladder was investigated.
G tolerance was 3.4 Gz (range: 2.8-4.3) in condition I, > or = 6.5 Gz (4.5-9.0) in II, > or = 8.0 Gz (6.5-9.0) in III, > or = 8.9 Gz (8.5-9.0) in IV and > or = 9.0 Gz (8.5-9.0) in V. In the supplementary experiments, the anti-G suit afforded a 2.8-G protection, a third of which was contributed by the abdominal bladder. In the relaxed state, pressure applied to the airways was transmitted undistorted to the intrathoracic space. During AGSM, intrathoracic pressure rose to 10-14 kPa, regardless of whether AGSM was performed with or without pressure breathing.
The anti-G suit and the pressure breathing system provide G protection of > or = 4.6 G, of which the anti-G suit contributes about 3.0 G. The C-protective properties of the anti-G suit and those of pressure breathing appears to be additive, whereas the G protection afforded by pressure breathing does not add to that provided by AGSM.
39架“鹰狮”战机的G值防护由全身覆盖的抗荷服、加压呼吸系统和抗荷动作（AGSM）提供。目的是研究（1）穿着抗荷服时加压呼吸与抗荷动作的相互作用；（2）抗荷服单独以及与加压呼吸系统联合使用时的G值防护特性。
在快速上升率G值时间曲线（≤9G）期间，对10名受试者在5种条件下进行了研究：（I）放松坐姿，未穿着任何G值防护装备；（II）放松坐姿并穿着抗荷服；（III）放松坐姿，穿着抗荷服并进行加压呼吸；（IV）穿着抗荷服并进行抗荷动作；（V）穿着抗荷服、进行加压呼吸并进行抗荷动作。在补充实验（n = 9）中，研究了腹部气囊提供的抗荷服防护所占比例。
I条件下的G值耐受能力为3.4Gz（范围：2.8 - 4.3），II条件下≥6.5Gz（4.5 - 9.0），III条件下≥8.0Gz（6.5 - 9.0），IV条件下≥8.9Gz（8.5 - 9.0），V条件下≥9.0Gz（8.5 - 9.0）。在补充实验中，抗荷服提供了2.8G的防护，其中三分之一由腹部气囊提供。在放松状态下，施加于气道的压力无畸变地传递至胸腔内。在进行抗荷动作期间，无论是否进行加压呼吸，胸腔压力都会升至10 - 14kPa。
抗荷服和加压呼吸系统提供的G值防护≥4.6G，其中抗荷服贡献约3.0G。抗荷服的G值防护特性与加压呼吸的特性似乎具有相加性，而加压呼吸提供的G值防护并未增加抗荷动作所提供的防护。
