G-Protection Afforded by the new "Libelle" hydrostatic Anti-G Suit in Comparison with a Modern Pneumatic Anti-G System
Ola Eiken, Swedish Defence Research Agency, Stockholm,
Sweden
Co authors, R Kolegård, B Lindborg, M Aldmann, K-E Karmer, J
Linder.
The G-protective properties of the new hydrostatic "Libelle" anti-G suit (L) were compared to those of the pneumatic anti-G ensemble used in the JAS 39 Gripen aircraft (AGE-39). Three pilots were studied in a centrifuge using:-
- The L suit in combination with muscular straining
- The AGE-39 suit in combination with full anti-G straining manoeuvres (AGSM) throughout each high G exposure (Full Manoeuvre = FM)
- The AGE-39 suit in combination with AGSM during the initial part of each high G exposure (Reduced Manoeuvre = RM)
-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-intensity tolerance was 6.3 G (= mean range: 6.0-7.0 G) in the L-condition and 9.0 G in all subjects in the FM and RM conditions. Thus, during the ROR exposures, only the 6.0 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. It can be concluded that 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, whereas, whilst wearing the L-suit, G-tolerance was 6.3 G. It thus appears that the G-protection afforded by the L-suit is not adequate for use in a 9-G aircraft.
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