MAKING UH-1N PERFORMANCE CHARTS PREDICT BETTER

摘要

This paper highlights the importance of updating aircraft performance charts periodically, especially after modifications are made that could affect power required or power available. With an initial tasking of simply validating some draft performance charts, the test team quickly learned that not only were the draft charts unsafely inaccurate, the published Flight Manual seemed to have significant errors. The Flight Manual under predicted torque required to hover frequently, especially at conditions involving high gross weight and/ or high density altitudes. The test program thus evolved into a four phase project. Phase 1 covered the work done to spot check the draft charts. Phase 2 was intended to check the Flight Manual accuracy with additional test aircraft from operational units, and Phase 3 compared the Flight Manual to the U.S. Navy's UH-1N Flight Manual (with good results). Phase 4 testing found the test team developing completely new hover torque required charts and proving their accuracy under high, hot, and heavy flight conditions.