Orange runway lighting as a method for reducing bird strike damage to aircraft

Abstract

Insects and spiders which congregate at night around runway lights on airfields form an attractive food source, and thus draw a wide variety of birds and bats into the flight paths of aircraft. Aircraft can be severely damaged when they strike birds or bats. If the number of insects and spiders which are concentrated by runway lighting could be substantially reduced, presumably the frequency of this type of damage to aircraft would also be reduced. It was found that orange light which excluded wavelengths shorter than 530 mp attracted fewer insects and spiders by weight than white light of equal visibility to humans with normal vision. A reduction of 92% was achieved with a Pyrex orange runway light lens, formerly in general use in Australia but now replaced by a variety of white lenses to conform to specifications of the International Civil Aviation Organization. There are strong indications that these specifications should be amended in the interest of aviation safety to ensure that as many of the short wavelengths as possible are excluded from signal lights, and that orange should be the colour for the main runway lights.