According to this from the Wilson Bulletin
On 29 November 1973, a Rüppell’s Griffon (Gyps rueppellii) collided with a commercial aircraft at 37,000 ft over Abijan, Ivory Coast, western Africa. The altitude is that recorded by the pilot shortly after the impact, which damaged one of the aircraft’s engines and caused it to be shut down. The plane landed safely at Abijan without further incident. The remains of the vulture consisted of five complete and 15 partial feathers from the wings (secondaries, lesser, and underwing coverts), tail, neck, and breast. Sufficient details are apparent in these feathers to allow their certain identification as G. rueppellii, using comparative material in the U.S. National Museum of Natural History.
Aside: See also.