Performance and Directional Control Margin Flight Testing of the BLR Tail-Boom Strakes on the NRC Bell 412 ASRA

摘要

Tail-boom strakes, consisting of angled aluminium segments attached to the tail boom of a helicopter, have been proposed as a method of providing vehicle performance and handling improvements due to favourable effects on airflow over the tail boom, Flight tests were conducted on the Bell 412 helicopter at the National Research Council of Canada Institute for Aerospace Research to evaluate the effects of the Boundary Layer Research Inc. tail-boom strakes on aircraft performance and control margins. Performance was assessed by determining the power required for hover, level flight, and climbing flight at various referred weights for both the strakes-on and off (baseline) conditions. Control margins were examined by collecting trim control position data at various low airspeeds and relative wind azimuths. The results indicated that the strakes improved the pedal control margins at some azimuths resulting in the pilot requiring less left pedal when flying at low speed. However, the strakes did not have any measurable effect on the power required for hover, level forward flight, or climbs.