Preliminary Airworthiness Evaluation of the UH-1H with Hot Metal Plus Plume Infrared Suppressor and Infrared Jammer
Final rept. 16 Jan-18 May 1981 on Phase 1 and 2
ARMY AVIATION ENGINEERING FLIGHT ACTIVITY EDWARDS AFB CA
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The Preliminary Airworthiness Evaluation PAE of the UH-1H, with the Infrared IR Suppressor and ANALQ-144 IR Jammer installed, was conducted using a JUH-1H helicopter. A total of 20.7 hours were flown during this test program. This PAE was an evaluation of a redesigned IR suppressor and IR jammer installation for the UH-1H helicopter. The initial design was reported to have caused a degradation in directional stability. The installation was redesigned to reduce the airflow disturbance over the tail rotor and vertical stabilizer. This evaluation was conducted in two phases. Phase I 9.5 flight hours was a comparative evaluation of handling qualities of the UH-1H in both the standard and IR suppressor configurations. Phase II 11.2 flight hours was primarily a pressure and temperature survey of the IR suppressor configuration. The handling qualities of the UH-1H helicopter were essentially unchanged by the IR suppressor and IR jammer installation tested. The previously reported degradation in directional stability was not observed during this test. The tail boom surface temperatures were generally higher for the initial design and the structural implications of these higher temperatures should be investigated. One deficiency, the metal to metal contact between the engine exhaust ejector and the IR suppressor inner core support struts, was identified. Three shortcomings were also identified.
- Optical Countermeasures