G incapacitation in aerobatic pilots : a flight hazard.

PDFTech ReportFAA-AM-82-13DOT/FAA/AM-82/13Air pilotsPhysiological aspectsAcceleration (Mechanics)AlertnessAircraft accidentsGravitational forceHistoryCase studiesTolerance (Physiology)United StatesCivil Aerospace Medical InstituteKirkham, William R.Wicks, S. MarleneLowrey, D. LeeCivil Aeromedical InstituteUnited States. Office of Aviation MedicineNTL-AVIATION-AVIATIONNTL-AVIATION-Aviation Safety/AirworthinessUS Transportation CollectionThis report presents some historical perspectives of aerobatics and the physiological effects of G acceleration, especially as pertain to in-flight loss of consciousness (LOC) by the pilot. Several accidents and incidents are reviewed to illustrate that LOC occurs in some pilots during aerobatic maneuvers. Accelerometer recordings made during aerobatic performances are analyzed in regard to the G's acting on the pilot during the entire performance and during some specific maneuvers. Human tolerance to G's and specifically to changes from positive to negative G's and vice versa is discussed in regard to some published animal and human studies.This report suggests that oscillating G's as encountered in aerobatics tax the body's mechanisms to maintain blood perfusion of the brain--and consciousness. Suggestions are given to help pilots reduce the physiological hazards of G's encountered in aerobatics