I'm going to withhold my reservations about the specific wording of your OP and recognize it for what it is. IMO, this is a very effective way to go about the discussion. I sense sincerity in your tone, and whereas I might not agree with your conclusions, at least you are making a very professional, reasoned effort to focus on specifics.
Any problems with my wording are unintentional. I hope at least the intent is clear. This is a tricky subject.
That said, what is the explanation for the lack of Flight 93 debris in the ditch in Shanksville? Was the ground so soft that the plane drove itself deep into the soil? Or was the ground so hard that the impact disintegrated most of the plane, sending pieces hundreds of yards away? CNN reported that 95% of the plane was recovered, certainly the few Mossaui trial photos of 93 cannot possibly account for all of the material.
This to me is pretty straightforward. The aircraft, intact, is a hollow and rather light structure in terms of effective density and/or ballistic coefficient. It also impacted the ground at about 250 meters per second; as others here have remarked, comparable to the muzzle velocity of a .45 caliber pistol.
On contact with the ground, swampy or soft or not makes very little difference. The contact is so fast that impact is dominated by momentum and inertia, and the physical strength of materials -- both the soil and the airplane -- contributes little. The ground is approximately three times as dense as a wing section that is totally filled with fuel, and about
twenty times as dense as the passenger cabin, on average. Most of the airplane is empty space. As a result, with such a violent impact, directed at a sharp angle to the ground, the aircraft will be almost totally destroyed in a matter of milliseconds.
Once the aircraft ceases to be a single object, the chunks that remain are different ballistically. The average piece of aluminum and plastics is now only about two or three times less dense than the soil, and its frontal area decreases dramatically. This means some penetration of the pieces is expected, to a depth of a few feet. Denser pieces such as engine cores and flight recorders that were initially comparable to the soil density may travel farther, perhaps 20 feet. This is exactly what we saw.
Regarding the amount of material recovered, 95% is pretty darn good. The impact mass of the aircraft is probably not known to better than 2-3% accuracy to begin with. At rupture points, there will be some release of material as very small pieces, perhaps too small to be screened without an extremely careful archeological effort. There are also going to be some minor mass losses due to fire and random ricochets into the distance. In general, the NTSB only gathers pieces big enough for there to be a hope of identification. As a result, this is exactly the kind of impact performance and recovery we anticipate.
There's similarly no reason for the Moussaoui trial to include every single fragment as an exhibit. The mere catalogue of pieces of UA 93 debris probably runs hundreds of pages. Only a few are needed for the trial, as exemplars of the incident.
I hope that answer helps you determine whether or not UA 93 indicates a conspiracy, although I don't imagine these questions are quite enough to settle the larger question of whether any conspiracy is real or even possible. But it's a step in the right direction.
Mr. Mackey:
Is there air traffic control confirmation of where and when the four planes crashed?
If I were a Truther, this would put to rest any doubts about theories like no-plane, flyovers, etc. And it would prove that it was indeed Flight 77 (as opposed to some other aircraft) that hit the Pentagon.
There is radar tracking data corresponding to all four aircraft. However, Flight 93 in specific did pass briefly through a radar "dead zone" (I think it's the only one, but I'd have to hunt to be sure; I haven't looked into this in depth), and theoretically it might have been possible to pull a "switch." However, the depth of coordination, planning, and dumb luck required for this to have a chance of success would be extraordinary, and I don't see how this would fit into any conspiracy's plans in the first place.