Richard W. Schumacker

The work performed during thi program was directed toward determining the acoustic characteristics of simulated burn-through failures. To determine the feasibility of detecting this failure acoustically two types of jet engines (J-47 and J-57) were modified to simulate burn-through failures. Magnetic tape recordings of the modified engines were made to determiine the extent of the acoustic spectrum, the relationship of engine speed to ailure related sound pressure levels and acoustic spectrum, the effect of sensor location to detect the failure acoustically and characteristic acoustic specta at burn-through. The recorded data was analyzed by real time spectrum analysis and mean square techniques. Results indicated that the simulated burn-through failure acoustic spectra consists primarily of broadband random noise above 5 kHz. It was also determined that sensor location is an important factor in detecting burn-through failures. Basd on the results it is concluded that acoustic detection of a burn-through failure is feasible. Recommendations for a monitor and detector based on the results of this program have been included. Volme II contains engine tests raw data and is available on loan from the DOT Library Services Division, TAD-494, 800 Independence Avenue, Washington, D.C. 20591

Richard W. Schumacker

The work performed during this program was directed toward determining the acoustic characteristics of simulated burn-through failures. To determine the feasibility 0 detecting this failure acoustically two types of jet engines (J-47 and J-57) were modified to simulate burn-through failures. Magnetic tape recordings of the modified engines were made to determine the extent of the acoustic spectrum, the relationshi of engine speed to failure related sound pressure levels and acoustic spectrum, the effect of sensor location to detect the failure acoustically and characteristic acoustic spectra at burn-through. The recorded data was analyzed by real time spectrum analysis and mean square techniques. Results indicated that the simulated burn-through failure acoustic spectra consists primarily of broadband random noise above 5 kHz. It was also determined that sensor, location is an important factor in detecting burn-through failures. Based on the results it is concluded that acousti detection of a burn-through failure is feasible. Recommendations for a monitor and detector based on the results of this program have been included. Volume I contains the Sonic Analysis.

R.E. Reinke

The only uniform feature in the toxicology of burning plastics are those of the toxicology of fire: heat, carbon monoxide, deficiency of oxygen, other combustion gases, and smoke. The hazard from combustion or thermal decomposition of plastics should be compared under equivalent conditions with that of wood or other appropriate materials. This comparison provides a basis for present assessment of hazard pending a more standardized evaluation anticipated in the future.

R.E> Darling

The DC-9 commercial aircraft structure and systems are reviewed to determine the optomum location to place a discovered explosive device for the best chance of survial of the aircraft and minimization of casualties. The damage that would be caused by the explosion and the structural residual strength are determined.

The study revealed that the best place to put the bomb to do the least damage would be on the ventral stairs for those airplanes so equipped. On other DC-9 airplanes, the bomb should be put in the tail cone.

R.F. Salmon

The Federal Aviation Administration's (FAA) crash-safe fuels program is a segment of a primary mission to improve the overall crashworthiness of aircraft. The objectives of this program are to reduce the probability and severity of fire during aircraft ground-crash situations. The approach being taken by the agency is a direct attack on the source of the aircraft fire problem by fostering the development of turbine engine fuels that will provide a significant reduction in the ground crash fire hazard when fuel is inadvertently released from an aircraft's fuel system.