W. Reeves, G. Dake, L. Chance, J. Guthrie

A new group of polymers made by reacting tris (1-azirdinyl) phosphine oxide, referred to as APO or tris (1-azirdinyl) phosphine sulfide, referred to as APS, with tetrakis (hydroxymethyl) phosphonium chloride, referred to as THPC, are good permanent type flame retardants for cotton. All three of theompounds are water soluble crystalline materials. This application of APO- or APS-THPC resins to textiles consists of padding fabric in aqueous solution of the compounds, drying the fabric, curing it about 140 degrees C. for about 5 min. to polymerize the compounds and then rinsing the fabric to remove any unpolymerized materials.

About 8% of the resins in 8-oz. Cotton twill or sateen is adequate to make the fabric pass the vertical flame test before or after 15 laundering. The flame resistance is also followed by an acid fluoride sour after each laundering. The flame resistance is also very durable to boiling alkaline soap solutions.

The properties of fabric treated with these new polymers are, in general, excellent. The hand and strength of the fabric is only slightly different from that of untreated fabric. The flame resistant fabrics are to rot and mildew.

L. Bryant

It is required by CAR 6.384 that in the event of fire in the engine compartment, a controlled landing of the rotorcraft can be made. This report has been prepared to show that, in the event of such a fire, the Vertol 42 Helicopter will maintain sufficient structural strength to make a controlled emergency landing.

R. R. Romanowich

The spontaneous ignition temperature of combustible fluids has been of great interest to the aircraft industry for a number of years now because of the fire hazard associated with operation of aircraft power plants.

P. Lynahan

The current military helicopter, Vertol Model H-21 is being certified to CAA requirements as the Vertol Model 42. In order to meet the fire protection requirements of the CAR Part 6, and Amendment 6.4, certain changes to the military configuration are considered necessary.

This report presents those proposed changes, the premise under which the changes were established, and a summary of the substantiating test results.

Lyle E. Tarbell

A continuous type of fire-detection system for the B-36 aircraft nacelle was designed jointly by qualified personnel of the Department of Air Force, Civil Aeronautics Administration, and detector manufacturers. Two manufacturers, using their own equipment, then made similar installation of the system in the B-36 test nacelle at the CAA Technical Development Center. This system was evaluated by fire tests under simulated flight conditions and was found to be effective. Only minor changes were recommended as a result of the tests. Shortly thereafter, the company which submitted the lowest bid was awarded a contract to supply fire-detection equipment for installation on all operational B-36 aircraft.

At the time the award was made the forward portion of the nacelle was, for all practical purposes, a portion of the wing. Subsequent modifications to the nacelle, however, crated was new zone in this region. Because the protection afforded by the original detection system was limited to the engine and lower accessory compartments, further tests were conducted to contrive an effective arrangement of the system in the new zone. The system described in this report is recommended for protection of the entire revised B-36 aircraft nacelle.