Richard G. Hill, John J. Collins

Tests were conducted with three different size gallery carts having the same ventilation area. Internal compartment temperature and weight loss were monitored. The results showed that the volume had little effect on the fire when the fire was ventilation controlled.

A.W. Coaker

A set of new vinyl compounds was prepared anticipating the publication of new requirements for limited smoke cables, to provide formulation guidelines. Commercial cables were used as controls and bulletinzed compounds were made into TW and THHN tray cables. A new facility built by BF Goodrich to determine full-scale fire performance f cables in vertical tray tests (on CSA FT-4) and the cone RHR test apparatus were used on 16 cables. The CSA FT-4 test were used also for measuring continuously heat release, smoke release and mass loss. Some cables had previously been tested at UL. Results in the two facilities showed excellent agreement for clear passes and clear failures. However, a cable rated borderline pass at UL failed in the BF Goodrich facility. Data from the cone correlated so well with cable tray results that the latter could be predicted from the former with reasonable accuracy. The final conclusion was that cables made with bulletinized vinyl compounds or with other materials tested emitted higher levels of heat and smoke than cables made with the new experimental compounds.

Richard G. Hill, Constantine P. Sarkos

Full-scale fire tests, conducted in the United Kingdom (U.K.) under the auspices of the Civil Aviation Authority (CAA ), have demonstrated the feasibility of an onboard cabin water spray system for providing a marked improvement in survivability during a postcrash fuel fire. Developed and evaluated by SAVE, Ltd., the system produces a fine water spray or mist consisting of a “range of water droplet diameters.” A fine water spray system, such as developed by SAVE, Ltd., is capable of providing fire protection with relatively low flow rates of water. The spray system that has been tested is a “breadboard” design for the purpose of demonstrating concept feasibility.

An outline of a program to develop a cabin water spray system for safe and effective installation in a commercial transport airplane has been prepared and is shown in a flow diagram (figure 1) depicting major projects and order of accomplishment. Initially, controlled full-scale tests are being conducted to document the additional time available for escape as provided by the current SAVE system. Concurrently, a study is being undertaken to address the various problems associated with an inadvertent discharge of the water spray system while an airplane is in flight or on the ground. The results of these initial studies will be factored into a benefit analysis to determine the potential for lives saved (similar to analysis conducted by the Federal Aviation Administration (FAA) and CAA for passenger protective breathing equipment). Presuming that the benefits will outweigh the disbenefits, the next steps will be to optimize the spray system for installation in an airplane and to develop design requirements and specifications. Additional full-scale tests would follow to verify the additional time available for escape provided by the optimized system. Another benefit analysis would determine potential lives saved for the optimized system. Finally, a decision would be made as to whether to proceed with a regulation requiring an onboard spray system for the commercial airplane fleet.

G. Slusher, A. Abramowitz, and W. Neese

A test study was conducted using the Halon 1211 and Halon 1301 fire extinguishing agents and aerosol smoke to study their behavior in a pressurized Cessna C-421B

Halon fire extinguishers were discharged and monitored at various locations to determine the concentrations of neat halon gases present, their dissipation rates and any resultant toxic threat to the occupants. Artificial smoke was also generated at various locations and was measured at three fixed locations in the aircraft, thereby providing localized visibility information as well as ventilation data.

Peak halon concentrations were considered adequate to extinguish most fires. Halon dosages for the pilot and copilot were low or zero and those for the passengers were also low in relation to the toxic limits recommended.

The high ventilation rates in the cockpit area contributed to clearing smoke from the cockpit quickly. It also prevented the smoke from entering the cockpit when it was released in the passenger cabin.

Thomas C. Hillman

A review of past and state of the art aircraft fire/explosion detection and extinguishing components is presented. The lessons learned from previously fielded systems are briefly discussed so that they can be applied to the modern protection systems as they are implemented.

Also, the operational features and characteristics of both fire and explosion protection components and equipment are identified and discussed so that trade studies based on these components strengths and weaknesses can be conducted. By appreciating these components strengths and limitations, a system definition, which is optimized for the given application, can result. The application of detection and suppression technologies to select aircraft environments is also discussed. Environments considered included: fire protection for engine powerplant compartments, fire and explosion protection for vulnerable dry bay compartments, explosion protection for aircraft fuel tanks, and fire protection for aircraft cargo bay compartments.

Based on the parametric characteristics of the perceived hazard, the protection systems and components, and the specific environment of the aircraft, which requires protraction, the definition and configuration of an optimized approach for protection can better be defined.