Charles A. Hughes

Tests were conducted to study the effect of element-wall thickness on the operation of continuous fire-detector systems. Walker Kidde & Company, Inc., furnished the elements tested, and by Thomas A. Edison, Inc. They included the standard, thin-wall, and the heavy-wall types from both companies, and a double-wall Edison element with the same diameter as the thin-wall element. This double-wall element was claimed to be more rugged than the thin-wall element.

The elements first were placed in an electric furnace and subjected o a slow rate of temperature increase to check the similarity of the temperature resistance characteristics of the core materials between the heavy and thin wall elements, because differences would influence the test results. The elements then were tested by placing them over a standard burner at 1500 degrees and 2000 degrees F, to obtain response and clearing times.

A second series of tests was conducted on an installation of the heavy and thin walled elements placed side by side in an engine bay of a test cell mounted F-89 airplane, using controlled test fires during simulated operation of the airplane. The results of the tests indicated that response and clearing times were increased appreciably by use of the heavy wall elements and that these elements did not meet the requirements of SAE Specifications AS-401A, Section 7.1 (Response Time). For the Edison Double-wall element, response and clearing times at 1500 degrees F flame temperature were not appreciably different from those of the thin-wall elements. At 2000 degrees F, however, the response and clearing times of the double-wall element were somewhat longer than for the thin-wall elements. The double-wall element met the specification requirements for response times only when calibrated for ambient temperatures below 450 degrees F.

C. Hamalaninen, W. Reeves, J. Guthrie

A permanent type flame retardant based on a bromoform addict adduct polymer of allyl phosphonitrilate in combination with THPC resin has been developed for use with cotton fabrics. The combination flame retardant is applied to fabrics from aqueous emulsion using conventional textile finishing equipment. The flame retardant is very efficient, 8 oz twill and sateen are made highly flame resistant with as little as 13% resin add-on

L.A. Asadourian

Fire tests were conducted in the accessory section of a full-scale operable CV-340 nacelle in order to evaluate the extinguishing system used in this powerplant. A study was made of the recommended emergency procedure in which the exit air-vent at the top of Zone 2 is closed during extinguishment. Comparative studies were made of emergency procedures in which the vent door was left open and in which both the vent door and the air inlet duct to the zone were closed.

L. A. Asadourian

During the period that fire-detection and extinguishing tests of the CV-340 power plant were in progress, the installation was also studied with respect to its fire resistance. Air flow and leakage in the power and accessory sections were studied with the aid of a dye introduced into the air stream upwind of the nacelle under simulated flight conditions. The dye technique proved to be a practicable means of detecting loose fits between mating parts. Test fires in the nacelle revealed which materials and components are most likely to fail during a power-plant fire. In many respects, the nacelle was exceedingly well constructed from the standpoint of fire safety. This was due in part to the unique design and to the generous use of stainless steel. However, the sealing materials used between mating surfaces were found to be vulnerable with the result that the confinement of fires was not successful. The destruction of certain seals permitted some fires to extend to the outside of the nacelle, a fact which complicated the extinguishment problem. A change in fabricating materials of one or two items of equipment are recommended.

L.A. Asadourian

During the period that fire-detection and extinguishing tests of the CV-340 power plant were in progress, the installation was also studied with respect to its fire resistance. Air flow and leakage in the power and accessory sections were studied with the aid of a dye introduced into the air stream upwind of the nacelle under simulated flight conditions. The dye technique proved to be a practicable means of detecting loose fits between mating parts. Test fires in the nacelle revealed which materials and components are most likely to fail during a power-plant fire. In many respects, the nacelle was exceedingly well constructed from the standpoint of fire safety. This was due in part to the unique design and to the generous use of stainless steel. However, the sealing materials used between mating surfaces were found to be 'vulnerable with the result that the confinement of fires was not successful. The destruction of certain seals permitted some fires to extend to the outside of the nacelle, a fact which complicated the extinguishment problem. A change in fabricating materials of one or two items of equipment are recommended.