Hazard potential of ejection with canopy fragmentation

W. Y. Chiou, B. L. Ho, D. L. Kellogg

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


The hazard potential of ejection with canopy fragmentation was evaluated by horizontal sled tests. A series of 14 ejections of tandem seats with 1st or 95th percentile anthropometric dummies were performed at sled speeds of 0, 150, 350, and 600 knots. Canopy-mounted miniature detonating cords (MDC) were fired in nine and not fired in five ejections. Maximal impact loads on each dummy's neck, knees, and shoulders were measured, and noise levels inside and outside the helmet recorded. The acceleration waveform for each dummy was recorded and used to calculate a dynamic response index (DRI) to assess the risk of spinal injury. Impacts with canopy fragments during ejections resulted in minor visible damages to the dummies and their equipment regardless of MDC firing. It was noted that MDC firing significantly attenuated the mean neck load (231±63kg, unfired, to 108±20kg, fired, p<0.05). Noise levels with MDC firing averaged 162dB. The mean DRI of dummy Gz for the small dummies was significantly greater than for large dummies (20.8±0.44 and 18.05±0.98, respectively, p<0.05). We conclude that superficial injuries to ejecting pilots and their equipment is not a hazard with the canopy fragmentation system; however, spinal injury may occur at rates of 5 to 50% depending on the size of the pilot.

Original languageEnglish (US)
Pages (from-to)9-13
Number of pages5
JournalAviation Space and Environmental Medicine
Issue number1
StatePublished - 1993
Externally publishedYes

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health


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