Any idea where you got the understanding that the door was shut during the cooper flight? One person has said that a crew member said they didn't feel any pressure pulse, so I've wondered why that would be.
This is from the FBI website on McCoy
Richard Floyd McCoy, Jr. - Aircraft Hijacking
Certain names in the following description are fictitious names to protect peoples' identities.
Richard Floyd McCoy, Jr.
Fourteen year-old Peter Fanning (fictitious name) of Provo, Utah, made a surprising discovery. Lying in front of him, beside a steel culvert, was what he thought might be a parachute pack. He brought the strange object to his father who was replacing a flat tire on the family car a short distance away. The father notified the local sheriff of their find after returning home that afternoon.
It was soon learned that the Fannings had stumbled upon one of the four parachutes furnished to a lone gunman who had commandeered a passenger plane on April 7, 1972, in the Colorado skies.
United Airlines Flight 855, a Boeing 727 en route from Newark, New Jersey, to Los Angeles, California, with 85 passengers and a crew of six, had resumed flight after a Denver, Colorado, stopover.
Approximately 20 minutes after takeoff, at 5:18 p.m., a male passenger was observed in his seat holding a hand grenade.
For more information:
- Related Story
A stewardess, notified of the situation, immediately advised the captain. An off-duty pilot known to be on board as a passenger was requested to discreetly walk around and assess the situation only to have the person in question draw a pistol as he approached. The gunman handed over a sealed envelope, labeled "hijack instructions," and stated, "give this envelope to the girl and have her take it to the captain." A stewardess complied, and the off-duty pilot returned to his seat.
The stream of events had transpired so quickly that most passengers were unaware of the threat. Captain William Olinsky (fictitious name) discussed the matter with some crew members and decided to land at nearby Grand Junction, Colorado, where he would radio for law enforcement assistance on the ground. Olinsky then announced over the public address system that the aircraft was experiencing a "minor mechanical problem" and would land shortly.
The envelope with the hijack instructions was then opened by the captain. Inside were two typed pages of highly detailed directions, a hand grenade pin, and a bullet. The "instructions" required Olinsky to land at San Francisco International Airport, and park at "Runway 19 left." There, he was to follow certain procedures which designated the number of persons allowed near the plane at one time, and the distance from the aircraft that all vehicles other than those containing fuel were to be kept. In addition, the hijacker demanded $500,000 in cash, four parachutes, and the return of all written or typed directions given during the course of the flight.
The crew decided to comply and notified San Francisco of the hijacking and intended landing. A flight crew member announced to the passengers that the Grand Junction airport could not handle the "necessary repairs" after all, and it would be necessary to divert to San Francisco. From this point on, normal operations continued on-board.
In consideration of the safety of all aboard Flight 855, United Air Lines officials decided to meet the demands upon the plane's landing at San Francisco. Two flight bags loaded with cash and four parachutes were delivered to the plane. The hijacker, who had assumed command on touchdown, gave up his baggage check and had his luggage brought aboard. Fuel trucks hurriedly filled the plane's tanks with thousands of gallons of jet fuel. After seeing the completion of his written directions, some three hours after the plane had parked, the gunman released the passengers and one of the stewardesses. He then ordered the rest of the crew into the cockpit and took a position in the rear of the aircraft.
The hijacker then used the intercom to summon a stewardess. He gave her another set of flight instructions, telling the pilot to take off towards the east, climb to 16,000 feet, and fly precisely at 200 mph on a course that would overpass several specific Utah communities. The messages, now hand-printed, between hijacker and pilot were sent with increasing frequency, always using the stewardess as a courier. The cabin was ordered depressurized, and the gunman warned that if any pursuit planes were spotted he would detonate a hidden explosive device after he had jumped, before the plane could be landed.
The hijacker opened his luggage and covered the peephole between the cockpit and cabin. Observed by Second Officer Floyd Smith (fictitious name) through a slight space under the cockpit door, the hijacker quickly put on a jumpsuit, helmet, and parachute. Once he had shut off the cabin lights to better view the ground, the gunman demanded to be kept abreast of wind, ground, and air speeds; altimeter settings; and sky conditions.
http://www.fbi.gov/about-us/history/famous-cases/richard-floyd-mccoy