Reheat - Hole in the Ground, page 9

Originally posted by turbofan
[13] Largest peice of Flt 93 was half a ton
Normally happens in a shoot down, or mid-air break up. Wait...where
did I read that before?

This one just *screams* out for a correction.

"Normally happens in a shoot down"? "Normally"? You are versed (well or otherwise) in the aerodynamics of what "normally" happens in an air-to-air shootdown?

While I would enjoy hearing a demonstration of that expertise, I doubt it would be forthcoming

Any idea what an AIM-9 Sidewinder's 20 lb warhead would do to a 250,000 lb 757?

OR what a AIM-120 AMRAAM missile's 50 lb warhead would do to a 250,000 lb aircraft?

Those are the two missiles that could have conceivably been used since any aircraft flying that day were of an Air Force- flavor (i.e. ANG or Air Force).

Air to air missiles are designed to bring down a relatively compact tactical aircraft. Their blast-frag or blast-annular warheads throw out an annular ring of titanium or other dense material, knowing that any impact at that speed with a tactical military aircraft will usually result in some hydraulic or fuel line be severed or some other critical system damaged.

Examples: The DHL incident at Baghdad - a Strela SA-7 (heatseeker, as a matter of fact) didn't track on an engine, but rather impacted the port wingtip. That warhead was only 2.5 lbs, but it messed up hydraulic and fuel lines to the point the aircrew had to use differential thrust to control the aircraft.

KAL 007, shot down by the Soviets in the early 80's, was hit by 2 air to air misilles (proximity fused) and continued to fly for an additional 2+ minutes in a gradual descent before either crashing or making a water landing. The Anab missiles fired by the SU-15 had a big warhead, over 80 lb in each of the 2 missiles, and that STILL didn't get an airborne kill on the 757.

A 20 lb Sidewinder warhead or the 50 lb AMRAAM will screw up one of those big GE or RR turbofans to be sure. The AMRAAM would do some damage to the side of the fuselage or wherever it would impact (depending on what radar mode the missile is tracking in), but it is not going to render the aircraft into pieces such that the "largest piece is half a ton".

Even working the dynamics of the event, if UA93 was tooling along at 1000 or 2000 feet, 500-whatever knots, a Sidewinder blowing up an engine will cause problems, but those aircraft (as part of their design and certification for Extended Twin Engine Operations (ETOPS) and overwater operations) fly very well on one engine. Would a sidewinder warhead detonation cause severe hydraulic loss or some other control ability problem? Possibly, but nothing would cause the instantaneous destruction of the aircraft to the point that the single largest piece would be a half-ton.

And what happens if and when the aircraft breaks up - either from aerodynamic forces or that 20 or 50 lb warhead magically hits a "sweet spot" and disintegrates the aircraft? Each and every piece, lacking thrust, will immediately begin to achieve terminal velocity. At the altitude the 757 was, if that scenario happened wreckage would be vast and spread over a much, much, much larger area than what was found and multiple...let me repeat that....MULTIPLE large pieces would remain since impact with the ground at terminal velocity (and I know terminal velocity related to the density, size and weight of the object in question) is not at a speed sufficient to render aircraft wreckage into minute, small pieces.

No, the only sort of accident that could have caused that debris would have been a controlled, high-speed dive into the ground at something near or approaching a 90 degree angle. I know ruling out the alternatives (missile shoot, for example) causes you CIT and PfT boys heartburn, but so be it.

I think you need to go back and get just a *tad* smarter on what is "normal" in an air to air shootdown, especially when a 250,000 lb 757 and 20 or 50 lb warheads are involved