Experimental assessment of low noise landing gear component design

Abstract

Landing gear related airframe noise is one of the dominant aircraft noise components at approach. It therefore is essential to particularly reduce landing gear noise. In the European SILENCER project, advanced low noise gears had been designed and tested at full scale. In the current European co-financed project TIMPAN (Technologies to IMProve Airframe Noise) still more advanced low noise design concepts were investigated and noise tested on a ¼ scaled main landing gear model in the German-Dutch Wind Tunnel. A variety of gear configurations were tested including a new side-stay design, different modifications of bogie inclination, wheel spacing, bogie fairings with different flow transparency, leg-door configu-rations and brake fairings. The acquired farfield noise data are compared against the results from a landing gear noise prediction model, transposed to full scale flight conditions and compared against the full scale test data obtained for the SILENCER advanced A340 style 4-wheel main landing gear. An optimal combination of tested gear modifications led to a noise reduction of up to 8 dB(A) in terms of overall A-weighted noise levels relative to the SILENCER reference gear configuration.