Aircraft Jet Engine Exhaust Blast Effects on Par-56 Runway Threshold Lamp Fixtures

The effects of jet engine exhaust blast on PAR-56 on lamps located at the runway threshold were measured in this project. Sensors were placed on and near the lamp assemblies which measured blast velocity and temperature, bulb face temperature, lamp fixture acceleration and sound pressure level. These sensors were coupled to a computer-controlled instrumentation system housed in a van located near the threshold of runway 13 at La Guardia Airport. Data were acquired during the engine runup and takeoff roll of some 162 aircraft during the measurement phase. The data were recorded on digital magnetic tape and video tape to form a permanent record of the raw data. The data were later plotted and analyzed, both manually and using a computer in order to extract the worst case environmental parameters encountered during the measurement phase. A prediction algorithm was developed to allow prediction of key environmental effects on the PAR-56 lamps caused by new aircraft or aircraft not measured. The algorithm was developed by correlating the acquired data against the manufacturers published jet exhaust blast velocity and temperature contours. A protective shroud was devised and installed on one of the instrumented lamp assemblies during the last portion of data collection. The data suggest a beneficial reduction of the hostile jet blast effects measured on the shrouded lamp versus the unshrouded lamp.