(5) Military Specification 58095(AV), General Specification for Crashworthy, Non-Ejection, Aircrew Seat System (MIL-S-58095(AV)), contains specifications for limiting spinal injury created by whole body vertical acceleration.
f. Suggested Numerical Values for Aircraft Use. The following subparagraphs summarize the impact injury data that are suggested herein for use in assessing the performance of impact injury protection systems in civil aircratt, and these data are not to be considered as regulatory criteria. It is not intended that all of the suggested performance criteria should be used in every case to assess each impact injury protection system. when regulatory requirements are established, specific performance criteria will be defined within the rule. In such cases, the regulatory criteria take precedenc- over anything presented in this advisory circular. In the absence of a definitive regulatory requirement though, a manufacturer should select appropriate performance criteria, develop appropriate test procedures for the particular application, and demonstrate that the selected performance criteria have been met.
(1) Whole body impact tolerance -
(1) - Gx (2-point restraint) Figure 1
(ii) + Gz (2-point restraint) Figure 2
(iii) - Gy (2-point restraint) Figure 3
(iv) - G (3-point restraint) Figure 4
(2) Head injury - HIC ‹ 1000 (t2-t1 < 0.05 seconds)
(3) Chest injury - Diagonal shoulder belt load - 7.8 kN (1750 1bs.)
(4) Abdominal injury - No quantitative data suggested.
(5) Leg injury -
(i) In line with femur - 10 kN (2250 1bs.)
(ii) Patella (concentrated load) - 2.5 kN (560 lbs.)
(iii) Transverse (lower leg) - 4.45 kN (1000 1bs.)
(6) Spinal injury - Pelvic compression load - 6.7 kN (1500 lbs.)
A. Pontecosio oseph A. Pontecorvo Deputy Director of Airworthiness Par 6 13