Leaderboard

Basically, there is not sufficient information available to make a meaningful detailed calculation of this. So what follows here is the analytical equivalent of "hammer and tong engineering". During the FBI test flights, it is reported that one of the USAF parachutists did in fact walk to the bottom of the stairs. As he walked down the stairs he would also be moving toward the rear of the aircraft. This movement would cause a slight NOSE UP moment for the aircraft. The amount of this increase in moment depends on his distance from the center of gravity of the aircraft. As the aft stairs move downward, the aerodynamic force on the stairs can be resolved into two components. The component parallel to the fuselage reference line is the increase in drag. This force will be quite small compared to the overall drag of the aircraft which is probably already well in excess of 10,000 pounds. This drag force component will probably be below the center of gravity of the aircraft and will cause a slight NOSE DOWN moment for the aircraft. The vertical component of the aerodynamic force on the stairs will be up and will also cause a slight NOSE DOWN moment for the aircraft. Even with someone standing on the bottom of the stairs, where the wind chill factor is about 30 to 40 degrees below zero, the effect on the overall performance of a 727 is going to be slight and may not even be noticeable if the aircraft is on autopilot or being hand flown in even mild turbulence. We need to address a remark made by Rataczak that when Cooper jumped and the aft stairs slammed close it caused enough of a disturbance that his headset almost came off. It should be noted that the flight crew had been told by the FAA Chief Psychologist that Cooper would probably blow up the aircraft when he jumped. With this cheering news, when the stairs slammed into the fuselage and created a pressure disturbance in the cockpit as well as a lot of noise, I suggest that all four people in that cockpit did a lot of jumping thinking that the bomb had gone off.

Reserves and bailout rigs are considered emergency parachutes and require a licensed rigger and card.. Mains do not require a card,,, can be packed by owner.. However, it is not clear that mains don't ever get a card... if packed by a licensed rigger.. I just don't know the answer to this.. Do mains never get a card or is it optional??

My experience is civilian, but there is a lot of crossover, a lot of military jumpers also sport jump and I have known many of them over the years. When I learned in '79, many of my instructors were from the military. Military courses can be exceedingly detailed, a lot of their First Jump Courses in that day lasted a week (before the first jump), and the students would definitely know 'mains' and 'reserves', and probably the make and model of the gear they were jumping, and maybe the serial numbers of their particular rig. Yeah, that last part was kind of an exaggerated joke, but the point is valid. I don't think experienced jumpers from either genre would commonly use 'front and back' over 'main and reserve' amongst each other. They might use 'front mount reserve' to differentiate from piggyback gear when those were coming out. And bailout rigs might be front, chest, seat, or back to differentiate between the types of those, none of which are mains. Bailout rigs do not have secondary reserves. Bailout rigs are reserves for the original intent of landing with the plane. I could go into more detail, but who gives a fuck, none of it sticks anyways. I don't think a conclusion can be made what Cooper's experience was based on the terminology he used. I think it's possible he was using generic terms based on who he was talking to, rather than where he came from. He was describing what he wanted to people who wouldn't know much about them. Indeed, if Cooper was an experienced sport jumper, he may have used generic terms in order to hide that fact, so as not to narrow down the suspect pool. Getting bailout rigs would not necessarily be a deal-killing death sentence. Those things are designed to save lives, and they do. Andrade's research into WW2 bailouts confirms this. And some of them are steerable. ----------------- I don't make posts with the intent of backing up some people or slamming others. I just try to clarify parachuting logistics based on decades of experience, as current as yesterday. Some time ago I wrote a post about camaraderie based on shared interest. The way some of you can bitch and snipe at each other, I'm starting to think that we owe Blevins an apology.