This story has been going around the world for 50 years, and in different variations. According to some sources, the first time it appeared in a publication in USA in 1958, in the professional magazine "Meat and Game" of the California Associations of Game Producers (proven fact). The authenticity of the story, however, is questionable.
The FAA has at its disposal a unique device for measuring the strength of aircraft windshields, in case of a collision with birds at high speed (which happens not so rarely). This device is a powerful pneumatic cannon that shoots a chicken carcass into the windshield of an airplane at a speed approaching the cruising speed of a civilian aircraft (for jet aircraft, this is approx. 800 km/h, for piston engines in the 1950s this figure was probably smaller, maybe 400-500 km/h). According to the theory, if the glass can withstand a collision with a chicken at such a speed, then it should all the more withstand a real collision with a bird in flight.
A certain British engineering company developing high-speed trains borrowed this gun from the FAA to test the strength of the windshield of its
a new high-speed train. The cannon was brought to England, installed at the landfill, loaded with a chicken carcass and fired at the prototype train.
The result exceeded all expectations: the chicken broke through the glass, broke the back of the driver's seat and got stuck in the back wall of the car. The British sent test results to FAA and asked them if they had done everything correctly and if the gun was hitting too hard. After studying the description and consequences of the test, the answer was sent by telegram immediately: "Next time, defrost the chicken."