Not to be outdone by the private sector, the Air Force fires frozen chickens from a 60-foot battleship cannon refitted for use on a special "bird-impact range," where the "bird-impact resistance" of airplane windshields and other components is tested. Not surprisingly, the Air Force boasts the world's largest chicken cannon. It is powered by a massive compressed air device rather than gunpowder, but the chickens nevertheless attain lethal velocity. In fact, Air Force researchers were amazed to discover that windshields already proved bulletproof were embarrassingly far from chicken-proof, several bird-impact researchers said.
"It gets a little messy," says Randall Watt, head of the bird-impact range at Arnold Air Force Base in Tennessee. "After all, our standard bird package is traveling at up to 600 miles per hour when it hits. There's not much left."
A "standard bird package" is a 4-pound, thawed, unplucked fryer wrapped in plastic and loaded into a special shell casing that remains in the cannon while the chicken is catapulted headfirst into the target, Watt explains.
The chickens are bought live from poultry dealers ("We buy from the same source as Kentucky Fried Chicken" ), then the birds are gassed to death and popped into a regular, homestyle freezer, where they are kept 50 or so at a time until a new windshield prototype has to be tested. "We can shoot this launcher up to 1,200 feet per second, slightly supersonic," Watt says.
A supersonic chicken hitting a stationary windshield simulates the effect of a fast-moving jet hitting a slow-moving bird. The idea is to make sure windshields can withstand 500-knot collisions with standard bird packages--a goal as yet unrealized on many planes.