Recommendations for correcting the flying qualities deficiencies of the Gazelle HT Mk-3 helicopter

In November of 1992, the author conducted an evaluation of the Gazelle HT Mk-3 helicopter as a final project for the United States Naval Test Pilot School, The purpose of that trial was to briefly, but comprehensively, evaluate the performance, flying qualities, and systems of the Gazelle to assess its suitability for the unarmed scout mission. The trial consisted of ground and flight tests that evaluated the cockpit, ground handling, flight control mechanical characteristics, low airspeed, and forward flight flying qualities of the Gazelle. Flight tests also evaluated the performance of the Gazelle in hover, vertical climb, level flight, and forward flight climb and descent profiles. Throughout the four hours of ground tests and six hours of flight tests, three serious deficiencies jack stall, fenestron stall, and This were uncovered: negative, forward flight maneuvering stability, thesis presents the test methods and research used to uncover these deficiencies, investigates their influencing factors, and analyzes and recommends engineering modifications to mitigate their effects. The overarching goal is to determine inexpensive and straight forward modifications to mitigate these three It is also hoped that the analysis and recommendations in this thesis might serve as lessons learned for the future acquisition of similarly configured aircraft. undesirable characteristics.