A test profile was developed to evaluate the reliability of an electronic countermeasures (ECM) pod. The profile combines air and liquid temperature cycling and various vibroacoustic levels to duplicate measured inflight thermal and vibratory response of the ALQ-184 ECM pod.
An ALQ-184 ECM pod was equipped with an environmental data collection system that included 25 thermal sensors, 18 vibration sensors, and a telemetry system to allow real-time monitoring of response levels during captive flight. The pod was flown on F-4, F-16, and A-10 aircraft at Eglin Air Force Base (AFB) under typical operation mission conditions.
Thermal and vibration response date were analyzed, and a reliability test profile was developed that simulates operational mission conditions for the F-4, F-16, and A-10 aircraft. The test profile is expressed in terms of pod response and is based on using temperature-conditioned air to provide the thermal response of printed wiring assemblies, temperature-conditioned liquid to provide the thermal response for coldplates, and 16 different vibroacoustic levels to provide the pod vibratory response. Each vibroacoustic level used the spectral data from five critical accelerometer locations on the pod structure to defin the required pod response.
The 6 hr reliability test profile simulates the thermal and vibratory response for 29 sequential flight conditions for the three aircraft. During the profile, the pod electrical status is cycled between standby, transmit, and off modes. The reliability test profile was used to perform reliability growth testing on early production pods and is being used for reliability qualification and production reliability acceptance testing during production.