So, now you’re thoroughly confusing me, Robert. Why did you mention gyroscopic instruments being “all they needed” if they don’t have anything to do with anything?

Also, Rataczak’s initial report stated: “oscillations in the cabin rate of climb” and his statement to the FBI simply said “oscillations”.

There’s no reference to “pressure oscillations” until May 30, 1973 (FBI 41, p. 30). In that instance, the author of the 302 is referring to the transcript I have attached below. Note that while the person doing the transcribing inserts something about “pressure”, Rataczak doesn’t actually mention it.

There is a reference for “pressure fluctuation” on January 9th, 1972 (FBI 18, p. 414) after the drop test, but “fluctuation” is singular not plural. This is obviously in reference to the bump, and not oscillations.

“Fluctuation” in regards to pressure isn’t mentioned again until February 12th, 1980 after the money was found on Tena Bar. (FBI 9, p. 195)

There are a few conclusions that could be drawn here, but to me it indicates that the oscillations were not considered to be pressure-related until much later on and likely incorrectly due to the insertion of “pressure” into Rataczak’s quotes when he doesn’t actually say that. Instead, it’s possible that the oscillations were not pressure related at all - at least not directly.

The prevailing theory is that the movement of the stairs caused by Cooper walking down them caused the pressure in the cabin to “oscillate” or “fluctuate”. What evidence to we have that the oscillations were directly related to pressure at all?

In aviation, the term “oscillations” are usually used to refer to changes in longitudinal stability such as phugoid oscillations, short mode oscillations, or pilot-induced oscillations (porpoising).

Again, considering the plane was unpressurized, it’s possible the oscillations were not at all related to pressure, but to altitude. Or to say it another way “the changes in pressure were a reflection in changes in altitude rather than changes in pressure by another means (the airstairs moving)”.

What I mean is that the lowering of the airstairs by Cooper slowly walking down them created drag causing a disruption to the pitch of the aircraft and inducing minor long mode oscillations that the crew detected on the rate of climb indicator for an unknown amount of time and ceased when Cooper jumped.

This is something good ole hominid theorized over a decade ago.

I’m no expert, but it’s food for thought. I’ll have to dig a little deeper into it. I want to talk to some more people who are a lot smarter than me and know a lot more about this crap than I do and who can tell me if I’m full of it or not.

Chaucer, slow down here.  We need to restart this conversation with a blank sheet of paper.

The reference to the gyroscopic instruments was that they were all of the references the flight crew needed to fly through clouds which was what you were asking about.

The cockpit altimeter is a pressure instrument that is calibrated according to a "standard atmosphere" to measure altitude above sea level.

The cabin altitude gauge is a pressure instrument to measure the "cabin altitude".  When the fuselage is sealed, the cabin altitude can be controlled by the cockpit crew and will typically never exceed about 8,000 feet even if the airliner is at 30 or 40 thousand feet.  When the airliner starts descending to land, the cockpit crew will start to lower the cabin altitude at a comfortable rate for the passenger's benefit and when the flight attendants open the door at the terminal the pressure inside the cabin will be the same as the pressure outside the cabin.  That is, there won't be any air blowing into or out of the cabin.

When the cabin is unpressurized, as was the case with the hijacked airliner, the cockpit altimeter and the cabin pressure gauge should indicate about the same altitude.  If the altimeter in the cockpit has a steady reading and the cabin altitude gauge is fluctuating or oscillating then it is not caused by the airliner pitching up or down.  In the case of the hijacked airliner, the fluctuations were caused by the changes in the aft stairs position due to Cooper being on them.

The use of the singular and plural doesn't mean much in this situation.  Only a small number of people involved in the Cooper case had any aeronautical qualifications.  The phugoid was not a factor in the oscillations and there is nothing to suggest that the airliner's altitude changed during those oscillations.

The above is not an insult.

   

But Rataczak reported the oscillations on the rate of climb indicator (VSI), not the cabin altitude. So they function in a similar manner?

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Persistent pesky questions about them stairs and the oscillations and bump...

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...going down a couple of steps past that hinge point is going to lower the stairs enough to create pressure changes in the cabin that would be noticeable in the cockpit cabin altitude instrument...     ...this time, he goes way down the steps as far as he can, perhaps to the very end of the stairs, and jumps.  Cooper's weight on the stairs will not lower them to the same degree as they are lowered on the ground.  But when Cooper steps off those stairs they slam up into their closed position but don't lock there...     

In that clip from the Treat Williams movie, when the stunt guy jumps off the stairs, they retract very slightly and slowly. They certainly don't 'slam' shut, even momentarily. I would imagine the pilot could feel a bit of change on the pitch influence, but I don't see it re-sealing the cabin momentarily and causing a pressure event. For the stairs to behave in the way described, I would guess that Cooper would have to have pulled the emergency release, which should disconnect them from the hydraulic system and allow them to free-float. But I'm told that did not happen, that he did not pull the emergency release. So would there be that much variable from plane to plane, how much the stair door would be able to move while still connected to (dampened by) the hydraulic system?  ...??

I don't have a good answer for that either. I have heard different things - the stairs hydraulics were not deployed and the stairs were freefloating and vice versa. Regardless, it seems that the pressure bump was simulated during the drop test in January 1972.

Here is what I do know:  the cabin rate of climb and descent gauge uses a sensor in the cabin to measure cabin pressure altitude. During an unpressurized flight - like the Cooper hijacking for example - it will read approximately the altitude that the aircraft is at. It will respond just like the flight altimeter - going up and down with the aircraft.

I propose that the 727 was experiencing what's known as a phugoid.

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If the plane was experiencing a phugoid, that would be reflected as oscillations in the cabin rate of climb indicator. I think the slow extension of the airstairs by Cooper caused phugoid oscillations in the aircraft that the crew noticed on the gauges. When Cooper jumped, the crew experienced a pressure bump - a rather well-known phenomenon in aviation when the pressure of the cabin increases dramatically - that usually causes your ears to "pop". When that happened, the airstairs were no longer descending and the aircraft stabilized from its phugoid.

Thus, while both phenomena - the phugoid oscillations and the pressure bump - were caused by Cooper's behavior on the airstairs, they were distinct things. Whether the crew, the airline flight ops, or the FBI understood the difference when it happened or immediately after is the question.

 and a longer mode called the phugoid.



But the phugoid simply cannot explain the cabin pressure altitude oscillations or the bump when the stairs hit the fuselage when Cooper jumped.  It is just not possible.

Chaucer, the above is not an insult.       

Regardless, isn't important thing here it gave us the time of his jump?  Obviously it does not give the position of the aircraft in relation to the Victor 23 path in the sky?  That is what needs to be solved.   It could give a better location, or more confident one to perform another land search with metal detectors?  They sure brought in some high tech devices at Skinwalker ranch.  I wonder if any of that could help?  I wonder what Brandon Fugal thinks of this case?

Why don't you ask Brandon Fugal? I'm watching the "Secret of Skinwalker Ranch" on Amazon Prime.

Some of you people are horrible to each other.

Chaucer, I'm going to try and give you a simple answer to what I believe is your question about the 'oscillations'. There is a gauge that tells whether and by how much the airplane is climbing, descending, or flying level and maintaining a constant altitude. I'm not sure exactly what it reads to determine this. I'm sure Robert could give you a concise answer to that, but it doesn't seem like he's inclined to do so. But it has nothing to do with cabin pressurization. It might be tied into the altimeter reading, but I don't think so because the differences it reads and the reactions of the pilot or autopilot could be so subtle as not to affect actual altitude by very much.

When Cooper ventures out on the stairs and his weight pushes them down, the bottom of the stair door is going to push down on the airflow, which results in an upwards push on the tail of the airplane, resulting in a bit of downwards pitch. It operates by the same principal as the flight control surfaces, the ailerons, rudder, and in this case specifically like the elevators. Yeah, there is drag involved, as everything on the outside of the airplane causes drag, and there is pressure involved but not 'cabin pressurization' pressure, but the pressure the bottom surface of the door exerts on the relative wind/airflow/slipstream.

So when Cooper goes down the stairs a few times for whatever reason, each time it's going to give a bit of pitch influence, which would be read by that gauge. Thus, 'oscillations'.

Hayden provided the two backpack parachutes that were given to Cooper and he said they were identical.  The surviving backpack is now on display at the WSHM in Tacoma, WA.  The pictures of that backpack indicate that it was put together from a collection of parts that came from different designs and did not itself have a formal designation.

I looked at the pictures of Hayden's rig on Bruce's site. I do not see a 'Frankenstein rig' pieced together from a collection of parts of different designs. This is what I do see:

The harness is a different color from the container. This in and of itself is not that unusual. What is interesting is that the Pioneer label is specific to the harness, and not the whole rig. That big label on the backpad seems to have instructions on it, but I do not see a manufacturer on that. The container does not look pieced together, it seems to be of similar design to the NB's in that both are three-pin rigs with four pack-opening bands and similar ripcord routings. The pack and data card says Pioneer, so it is possible/likely that they made the whole rig. The military NB rigs are made to be rugged, to withstand years of use by different people and in different aircraft. Hayden's rig looks to be made of lighter weight material, which might be typical of rigs built for civilian use, they would be lighter weight and more flexible, and be subject to less wear-and-tear. The military would come up with that NB design, and over the years there may be several manufacturing runs which may be done by different manufacturers. I think I've seen later models of NB's made by Switlick, but it would not be unusual if Pioneer made them at some point. If so, it would not be unusual for them to make the harnesses in batches, then use some of those same harnesses for their other rigs. In the finished form, the harness/container is a singular unit and does not come apart. Those bailout rigs are reserves, and as such they have to pass tests for an FAA TSO. If that rig was not a legitimately manufactured rig, it would not be legal for a rigger to pack it, put his seal on it, sign the card, and provide it for use by someone such as Hayden. I think the notion of a pieced-together rig came from a statement somewhere from Cossey, but those 'pieces' would refer to the other components inside, notably the links, canopy, bridle, and pilot chute. Unless otherwise dictated by the manufacturer, he is free to choose those components as he sees fit, as long as they fit and function suitably, and are TSO'd for such use.

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Hayden provided the two backpack parachutes that were given to Cooper and he said they were identical.  The surviving backpack is now on display at the WSHM in Tacoma, WA.  The pictures of that backpack indicate that it was put together from a collection of parts that came from different designs and did not itself have a formal designation.

I looked at the pictures of Hayden's rig on Bruce's site. I do not see a 'Frankenstein rig' pieced together from a collection of parts of different designs. This is what I do see:

The harness is a different color from the container. This in and of itself is not that unusual. What is interesting is that the Pioneer label is specific to the harness, and not the whole rig. That big label on the backpad seems to have instructions on it, but I do not see a manufacturer on that. The container does not look pieced together, it seems to be of similar design to the NB's in that both are three-pin rigs with four pack-opening bands and similar ripcord routings. The pack and data card says Pioneer, so it is possible/likely that they made the whole rig. The military NB rigs are made to be rugged, to withstand years of use by different people and in different aircraft. Hayden's rig looks to be made of lighter weight material, which might be typical of rigs built for civilian use, they would be lighter weight and more flexible, and be subject to less wear-and-tear. The military would come up with that NB design, and over the years there may be several manufacturing runs which may be done by different manufacturers. I think I've seen later models of NB's made by Switlick, but it would not be unusual if Pioneer made them at some point. If so, it would not be unusual for them to make the harnesses in batches, then use some of those same harnesses for their other rigs. In the finished form, the harness/container is a singular unit and does not come apart. Those bailout rigs are reserves, and as such they have to pass tests for an FAA TSO. If that rig was not a legitimately manufactured rig, it would not be legal for a rigger to pack it, put his seal on it, sign the card, and provide it for use by someone such as Hayden. I think the notion of a pieced-together rig came from a statement somewhere from Cossey, but those 'pieces' would refer to the other components inside, notably the links, canopy, bridle, and pilot chute. Unless otherwise dictated by the manufacturer, he is free to choose those components as he sees fit, as long as they fit and function suitably, and are TSO'd for such use.

Well geez, I might just stand corrected. Flyjack has that container documented as WW2 era and cotton. I thought it looked kind of old, but I wouldn't have thought THAT old, and at least two riggers signed it off as airworthy, as late as '86?? That thing should probably have been in a museum before either Cooper, Hayden, or whoever replaced the harness got any of their hands on it! Sheesh...

Bit of talk recently regarding the comms relating to the jump time of Cooper.

Larry Carr told me personally (on Eric Ulis's Facebook page) that a transcript of the NWA comms with Flight 305 exists. In his reading of this, he confirms that when the pressure bump happened, they were not on the phone with NWA, but called afterward to report the incident. This comports with what Anderson said in 2014.

Carr said that the person doing the recording did not write down the time that the report was received, but instead estimated the time that the crew thought they felt the pressure bump.

This would seemingly eliminate the 8:11 jump time based upon the "Rataczak losing his ear piece" comm.

This would put the pressure bump an unknown amount of time AFTER the 8:11 time of the report of "oscillations". How far after is still a guess.