June 1968 – vol. 61, issue 6–277 Birds and aircraft.--The current issue of B.T.O. News contains a discussion by Dr. W. R. P. Bourne of the problem of collisions between birds and aircraft. This hazard is not new, but is becoming more serious as aircraft speeds increase and jet engines replace piston ones. It has been stated in Parliament that damage caused by bird collisions now costs the Royal Air Force a million pounds a year; ... This article is only available to subscribed users.To read more, please log in or purchase a subscription.