FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-65/20

Title and Subtitle: Tolerances of the human face to crash impact.

Report Date: July 1965

Authors: Swearingen JJ.

Abstract: Evaluation of the injury potentials of commercial airline seat structures, light-aircraft instrument panels, and other deforming structures requires data on forces that produce fractures, lacerations, or unconsciousness when applied to different parts of the face. Unconscious commercial passengers, although not seriously burned, may asphyxiate or burn to death in a few minutes.

Data of facial tolerances of living human heads and forces required to render unconsciousness were gathered by an intensive study of injuries in automobile accidents. These data were checked by making a series of 45 cadaver head impacts against deforming structures. Results show that blows of as low as 30 to 40 g for 10 to 40 milliseconds will produce temporary unconsciousness.

Maximum forces that may be tolerated without fracture when the face is impacted gainst a surface that is designed to deform and conform to the contour of the facial bones are: Nose, 30 g; single zygomatic, 50 g; teeth (3.6 sq. in.), 100 g; mandible, 40 g; forehead (1 sq. in.), 80 g; and forehead (4 sq. in.), 150 g. One cadaver head was impacted against a full-face molded block to determine if these tolerances were additive. The impact, the maximum attainable on the equipment (over 300 g), produced no fractures or lacerations.

Key Words: aviation injuries, tolerances (physiology), face (anatomy), wounds and injuries, head (anatomy), impact shock, aircraft seats, commercial aircraft, bone fractures, passenger vehicles, accidents.

No. of Pages: 30