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In-Flight Suppressant Deployment Temperatures



Donald Bein


This report describes review of DoD military fixed-wing and rotary aircraft fire mishap/incident data applicable to assess temperatures at which aircraft fire suppressants have been deployed in engine nacelle and APU compartment fires. Another model is also described, which was constructed to assess predicted nacelle compartment air temperatures at altitude, also taking into consideration aircraft airspeed, average nacelle airflow velocity, average engine case surface temperature, and average nacelle physical characteristics. An assessment is made of the model output versus some aircraft measurement data, fire suppressant boiling point criterion, as well as the history of altitude/temperature at which fire suppressants have been deployed. Additional analysis is also described that assessed aircraft operation in cold conditions, where the limiting temperature for fire suppressant release during take-off may be close to the (low) ground temperature. Risk assessments are also presented to quantify rate of occurrence of nacelle/APU fires and rates in which suppressants have been deployed taking into consideration altitude thresholds.
Special Publication (NIST SP) - 984-4
Report Number


Bein, D. (2006), In-Flight Suppressant Deployment Temperatures, Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed May 18, 2024)


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Created February 28, 2006, Updated February 19, 2017