AEROELASTIC STABILITY FLIGHT TESTING OF THE BA609 TILTROTOR

摘要

The Bell/Agusta 609 (BA609) is a nine passenger civil tiltrotor, being developed as a collaborative effort between Bell Helicopter Textron Inc. and AgustaWestland, a Finmeccanica company. The aircraft is currently undergoing development and envelope expansion flight testing, which will be followed by certification testing. The certification basis requires that the aircraft must demonstrate freedom from aeroelastic instability for all configurations and design conditions within the flutter clearance envelope through analysis and testing. This paper presents the test methods used to determine the aeroelastic stability of the fundamental wing-pylon modes and a comparison of test results with the analytical predictions. The results are presented as frequency and damping versus airspeed for different modes. In general the analytical damping predictions are conservative and no damping trends that indicate instability within the flutter clearance envelope are noted. The development and envelope expansion stability testing is progressing well, thus paving the way to certification testing.