Richard C. Dorshimer

A slip ringless propeller-mounted data system has been designed, fabricated and tested for the measurement of propeller blade stain during flight and ground operation of an instrumented aircraft. This data system is self-powered through the rotary motion of the test propeller, employs a 16 channel constant bandwidth Freejuency Modulated (FM) Multiplex and signals are capacitively coupled from the propeller to the aircraft. The FM Multiplex consists of 17 channels of information including propeller rpm and 16 strain gage channels containing information from dc to 1 kHz. An environmentally protected strain gage installation has also been a consideration of this program.

The FM Multiplex is split into four groups of signals with a frequency translation process in order to conserve bandwidth and/or recording time on an airborne tape recorder. Seven additional data channels are provided on board the aircraft for inclusion of parameters needed to define the aircraft operating conditions.

The data system was demonstrated for a period of 50 hours on an engine test stand during which the demodulated signals were observed and additional data was obtained relative to the system stability.

D. Gross

A previous report [1] described preliminary experiments on laboratory models of fire development in enclosed spaces. Using a 20 x 40 inch chamber it was found that within certain ventilation and physical property limits flaming ignition of a wall lining specimen by radiant heating would occur; and outside these limits flaming ignition would not occur.

This report summarizes additional tests performed in this chamber using small cubes of polyurethane cushioning foam, similar to that used in seat cushions. A larger chamber, 24 x 24 x 192 inch long, propagate down a long chamber. The polyurethane foam was exposed in a variety of ways, viz. open flame ignition, radiant heating and internal heating using an embedded electrical heater.

At this time only a summary of the experimental work is being presented. The analysis of the data and a projection of the findings will be presented in a later report.

Gus Brown, Richard Sulzer

The guidance value of the Arcata diamond rllnway centerline paint markings was tested by comparison with the U. S. standard centerline markings in the Dalto/P-3 visual simulation facility. Twenty experienced pilots participated in the testing. Results generally favored the U. S. standard centerline consisting of a 3-foot-wide interrupted stripe with l20-foot painted length and 80-foot gaps, as opposed to the lO-foot maximum width diamonds with 75-foot length and spacing. The only exception was that the diamonds were seen farther away prior to touchdown, a result that is attributed to the one-third larger total painted area.

J.P. Gillis

A study was made of flame propagation in a simulated aircraft vent system to provide design criteria for future vent system installation in aircraft. Determinations were made of flame and aircraft-on-ground. Temperature and altitude effect on flame speed were also investigated.

The geometric configuration of the simulated vent system caused momentary flame speeds in excess of 1000 feet per second and the associated pressures developed in some instances exceeded the structural limitations of typical aircraft vent ducts.

Conclusions indicate methods of reducing flame propagation speed in aircraft vent systems.

Department of Transportation

The Federal Aviation Administration is considering amending the emergency evacuation requirements and operating procedures for transport category airplanes.