A flock of geese caused a US military helicopter to crash in Norfolk earlier this year, according to investigators.
The aircraft was on a routine training mission from RAF Lakenheath when it went down on January 7 at Cley-next-the-Sea.
The birds rendered the pilot and co-pilot unconscious.
Captains Christopher Stover and Sean Ruane and Technical Sergeant Dale Mathews were killed, along with their female colleague Staff Sergeant Afton Ponce.
"A flock of geese took flight from Cley Marshes, likely startled by the noise of the approaching helicopters, and struck the MA (helicopter).
At least three geese penetrated the windscreen, rendering the mishap pilot and mishap co-pilot unconscious, and at least one goose struck the mishap aerial gunner in the performance of special mission aviator duties, rendering the mishap aerial gunner unconscious."
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