The Requirements for an Emergency Breathing System (EBS) in Over-Water Helicopter and Fixed Wing Aircraft Operations (RTO AGARDograph 341)

Abstract

When a helicopter ditches, it commonly inverts and sinks rapidly. Even if the accident is survivable, the astonishing fact is that fifteen percent of the crew and occupants will perish. The basic reasons why occupants have difficulty making underwater escape, have already been extensively discussed in AGARDograph No 305 by one of the authors titled “The Human Factors Relating to Escape and Survival from Helicopters Ditching in Water” published in 1989.

Since this was completed, the two authors have conducted further research on the principal causes of this regrettably high fatality rate. The conclusion to be drawn is that the occupants simply cannot hold their breath long enough to make an escape, and the cause of death is drowning. The fatality rate does not appear to be diminishing.