The FAA requires that passenger aircraft must demonstrate an adequate level of safety for passengers and crew during improbable failure conditions that result in a loss of pressure and cooling during flight. The FAA has identified human body core temperature increase as a heat stress indicator during failure conditions, and has specified core temperature limits that must be maintained in flight for an aircraft to comply with FAA requirements.
Because the direct testing of aircraft under specific extreme environments is difficult to achieve, ThermoAnalytics has pioneered a combined testing and simulation methodology that satisfies the FAA and reduces time to market of new aircraft. We provide engineering support to certify new aircraft to FAA requirement 14 CFR 25.831(g) using an approved Equivalent Level of Safety (ELOS).
We demonstrate compliance by instrumenting the aircraft, executing a flight test under the available ambient conditions while recording solar irradiance, mean radiant temperature of surfaces, thermal radiation flux, air temperature and air velocity at the skin of occupants.
These data are then corrected for extreme environmental conditions as required by the FAA. Using the corrected data as inputs, a simulation is performed using the ASHRAE two-node human thermal model or our standard Human Thermal Extension.