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## The Jump
At approximately 8:00 p.m., a warning light in the cockpit indicated that the aft airstair—the folding set of stairs at the rear of the 727’s fuselage, which could be lowered and raised in flight—had been activated or opened. The crew noticed a change in cabin pressure.
At approximately 8:13 p.m., the tail section of the aircraft pitched upward sharply. The FBI later reproduced this tail movement by dropping a 200-pound weighted sled from the aft stair of another 727 in a controlled test, establishing that the upward pitch was consistent with a person exiting the aircraft.
Two military aircraft—an F-106 and a T-33—had been dispatched to shadow Flight 305 from a distance. Neither crew saw a parachute deploy. Neither saw a body leave the aircraft. The night was dark, the terrain below was heavily forested mountains and ridgelines, and the conditions were not ideal for aerial observation. There was also, depending on the source, weather in the area—possibly light rain.
Cooper jumped into whatever was below him: mountainous Pacific Northwest terrain, darkness, early winter temperatures, and an unknown altitude. He jumped wearing a business suit and a raincoat. He took the money bag with him. He took one of the four parachutes—the evidence suggests he took a main chute, not the non-functional reserve. He left behind the other three chutes, his black clip-on tie, his tie clip, and his briefcase.
The plane flew on to Reno, landing at approximately 11:02 p.m. The aft stair was still deployed when it touched down. Cooper was not on board.