Jet aircraft noise and bird strikes: Why more birds are being hit

Abstract

The noise levels of departing and landing aircraft were examined as a function of type of aircraft at J.F. Kennedy International Airport in New York. In general, the wide-bodied aircraft (Boeing 747, L1011, DC10) were significantly quieter than the old-type, narrow-bodied aircraft (Boeing 707, 727). Noise levels varied when approaching planes were different distances from the test site. Noise levels did not rise significantly higher than pre-departure levels until the planes were between 600 and 800 m from the test site, and the planes traversed this distance in an average of 9–14 s. For landing planes, the narrow-bodied planes were significantly louder than the wide-bodied planes at touchdown, only 600 m from the test site. Wide-bodied planes had significantly more bird strikes than the narrow-bodied aircraft. These results indicate that birds have less warning of an approaching wide-bodied aircraft than they have for narrow-bodied aircraft. The bird's behaviour of facing and flying into the wind (in the same direction as the airplane is moving) increases the perception and decreases the flight speed of the bird, and increases the risk of a bird strike (particularly for the wide-bodied aircraft).