Engineers at a major aerospace company were instructed to test the effects of bird-strikes (notably geese) on the windshields of airliners and military jets. To simulate the effect of a goose colliding with an aircraft travelling at high speed, the test engineers built a powerful gun, with which they fired dead chickens at the windshields. The simulations using the gun and the dead chickens worked extremely effectively, happily proving the suitability of the windshields, and several articles about the project appeared in the testing industry press.
It so happened that another test laboratory in a different part of the world was involved in assessing bird-strikes - in this case on the windshields and drivers’ cabs of new very high speed trains. The train test engineers had read about the pioneering test developed by the aerospace team, and so they approached them to ask for specifications of the gun and the testing methods. The aerospace engineers duly gave them details, and the train engineers set about building their own simulation.
The simulated bird-strike tests on the train windshields and cabs produced shocking results. The supposed state-of-the-art shatter-proof high speed train windshields offered little resistance to the high-speed chickens; in fact every single windshield that was submitted for testing was smashed to pieces, along with a number of train cabs and much of the test booth itself.
The horrified train engineers were concerned that the new high speed trains required a safety technology that was beyond their experience, so they contacted the aerospace team for advice and suggestions, sending them an extensive report of the tests and failures.
The brief reply came back from the aero-engineers: “You need to defrost the chickens.”