Aircraft Cargo Compartment Fire Detector Certification 3 rd

Aircraft Cargo Compartment Fire Detector Certification. 3 rd Triennial International Fire and Cabin Safety Research Conference October 22 -25, 2001 Atlantic City, NJ. USA David Blake FAA Technical Center Atlantic City, NJ

Purpose Standardization of Detection Requirements. Reduce False Alarms

Standardization Federal Aviation Regulation/Joint Aviation Regulations Part 25. 858 Cargo compartment fire detection systems. If certification with cargo compartment fire detection provisions is requested, the following must be met for each cargo compartment with those provisions: (a) The detection system must provide a visual indication to the flight crew within one minute after the start of a fire. (b) The system must be capable of detecting a fire at a temperature significantly below that at which the structural integrity of the airplane is substantially decreased. (c) There must be means to allow the crew to check in flight, the functioning of each fire detector circuit. (d) The effectiveness of the detection system must be shown for all approved operating configurations and conditions. • Flight tests are required to show compliance with the above regulation. FAA Advisory Circular 25 -9 A. Smoke Detection, Penetration, and Evacuation Tests and Related Flight Manual Emergency Procedures. “The smoke detection test is designed to demonstrate that the smoke detector installation will detect a smoldering fire producing a small amount of smoke. ” • The airline/aircraft manufacturer requesting certification have used a wide variety of methods to generate “smoke” for the required tests. Particle size distribution, buoyancy, agglomeration characteristics, etc. vary considerably.

Project Partners

False Alarm Issue In 1998, the FAA mandated that all cargo compartments on passenger carrying aircraft be retrofitted with fire detection and suppression systems. The deadline to accomplish the retrofit was March 19, 2001. The rule change affected approximately 3000 airplanes.

False Alarm Consequences Direct Costs of Diversion • Estimated at $30, 000 - $50, 000 Indirect Consequences of False Alarms • Increased risk due to landing at unfamiliar or less adequate airports • Loss of confidence in detection systems. • Risk of passenger or crewmember injuries during evacuation.

Standard Fire Source Nylon Polyethylene Acrylic Polystyrene PVC PBT

Smoldering Fire (Pyrolysis) Spark Ignitors, 2 ml heptane Flaming Fire

Cone Calorimeter with FTIR gas analysis

Summary q. The flaming resin block shows good repeatability and produces multiple fire signatures that could be detected by multi sensor fire detectors. q. The smoldering (pyrolyzing) resin block has good repeatability but does not produce measurable quantities of combustion products other than smoke (aerosols). q. Current regulations and policy would not permit the flaming resin block to be the standard for detection in any size cargo compartment. A decision point has been reached on whether the regulations should be changed or different standards of detection need to be developed for different sized compartments.