A mistake TWA 800

originally posted by: pteridine
a reply to: 1947boomer
If this is true, what missile was used and where was it launched from? Manpads have small warheads and Stingers would tend to home on engines although it is conceivable that the center tank was hot enough for an IR lock.

One clue to answering this might be from the visual report of the NY Air National Guard helicopter pilot who was only a few miles from the explosion when it happened and flew his helicopter near to where the debris was falling into the water within a minute or so. He was close enough that he saw groups of seats with headless bodies still strapped in, splashing into the water.

As I mentioned before, this guy was a high-time F-4 pilot during Vietnam and witnessed many surface-to-air missile encounters. He reported that the missile that he saw that night in NY had two propulsive burns. The first burn he described as bright white and going basically straight up until it was above the altitude of the 747. There was a brief period of coasting followed by another burn as the flame turned toward the 747. The second burn was not as bright and was redder than the first. As the flame came down from above and behind the 747, it terminated in what he described as a high order detonation followed by the fireball of the 747's fuel igniting. Two separate events.

In a radar guided missile intercept, the object is to put as much energy into the interceptor as possible as quickly as possible, once the optimal launch time has been computed. This is done by accelerating vertically at supersonic speed to an altitude above the target. At that point, the missile has an energy advantage in both potential energy (altitude) and kinetic energy (speed). Then the boost stage of the interceptor is dropped and the sustainer engine is ignited as the missile flies out to the intercept point. The sustainer engine is lower thrust than the boost engine but is designed to keep the speed of the interceptor sufficiently high that the target can't run away or out maneuver the interceptor--usually around Mach 3+. This intercept strategy has been SOP for Soviet era SAMs for a long time and is why modern SAMs are two stage missiles.

Here's the interesting part. The Soviet built SAMs that were common in that era (SA-2) used a solid fuel rocket motor for the boost phase and a storable liquid propellant for the fly out phase. The US navy does not allow storable liquid rocket propellants to be used on their vessels because they consider it too dangerous. US Navy SAMs use solid propellants for both stages. If this had been a Navy SAM, both burns of the missile would have been the same color and brightness. If this had been an SA-2, the propulsive burns would have been exactly as the NY ANG pilot described them.

How would you get an SA-2 and its associated Fan Song radar unit into position? Put them on a boat near the flight path and dump them overboard after the hit.

The fuel tank fuel sending unit wire theory is plausible however, I’ve seen military drop tanks with the same fuel sending units, sketchy as heck, thrown around and hooked up with enough JP-4 vapor to make you pass out, not explode. The electrical current going through the wires couldn’t even make a spark if you tried. Very low voltage.

Not including the fact that this was a transcontinental flight, I seriously doubt the main fuel tanks would not be full (topped off) nor have such low volume of fuel to have enough (air) oxygen ratio below the suspect sending unit to ignite. This plane was full. Again the sending units do not produce that much voltage.

a reply to: 38181

The standard fuel load for TWA going to Europe didn’t include the center wing tank. They didn’t need that much fuel going east, so they didn’t use it. In the -100, the AC packs were sitting around the center wing tank, and heated the tank on the ground. This flight was late, which let the tank be heated close to the combustion point before they ever left the ground.

originally posted by: 38181
The fuel tank fuel sending unit wire theory is plausible however, I’ve seen military drop tanks with the same fuel sending units, sketchy as heck, thrown around and hooked up with enough JP-4 vapor to make you pass out, not explode. The electrical current going through the wires couldn’t even make a spark if you tried. Very low voltage.

I think the official explanation was that the energy didn't actually come from those wires, but came from a short in another part of the electrical system and arced into those wires from outside the tank at some point where the wires were damaged.

This was purely speculative though and they admitted there was no evidence of it. Which is funny because they dismissed every other theory on the grounds of "there was no evidence of it."

I feel like the final report is really inconclusive, and they should've just said that. They said the tank explosion is the most likely cause. There was circumstantial evidence that I think Zaph noted on page 1 of this thread, that one of the gauges was malfunctioning, indicating some kind of electrical problem. But electrical problems and odd gauge readings don't always cause explosions. The exact method of ignition was never determined from what I've seen.

a reply to: Zaphod58

The Packs, Thanks. That makes a bit more sense.

a reply to: 38181

They used an Evergreen -100, built around the same time, and simulated the departure with it, including the delay (I think it was three hours). They had temperature sensors all around the center Wing tank, and by the time they got to the altitude that 800 blew, the tank was recording temperatures above the combustion point of Jet-A. And they didn’t have an inerting system, due to political BS.

originally posted by: 38181
The fuel tank fuel sending unit wire theory is plausible however, I’ve seen military drop tanks with the same fuel sending units, sketchy as heck, thrown around and hooked up with enough JP-4 vapor to make you pass out, not explode. The electrical current going through the wires couldn’t even make a spark if you tried. Very low voltage.

Not including the fact that this was a transcontinental flight, I seriously doubt the main fuel tanks would not be full (topped off) nor have such low volume of fuel to have enough (air) oxygen ratio below the suspect sending unit to ignite. This plane was full. Again the sending units do not produce that much voltage.

As I understand it, the flight recorder showed about 50 gal of fuel in the center tank.

a reply to: Zaphod58

I've heard about the -135"s. In my opinion it was explained correctly. The explanation for Flight 800 doesn't fit. I'm not denying that it could happen. My problem is more with their explanation.

I believe that the 135's had refueled some aircraft and had partial tanks full of fuel. Flight 800 had full tanks with almost no empty space.

The 135's were descending when they had their explosions. Descent would mean that as altitude decreased, atmospheric pressure would increase, pushing air into the tanks through the ventilation system. That could give a fuel air mixture with the right ratio to explode if there was a source of ignition.

Flight 800 was ascending. As the air pressure decreased the atmosphere (mostly jet fuel vapors) in the empty sections of the tanks would be exiting out through the vents. There would be a reduction in air (oxygen) in the tanks. The ratio wouldn't have enough oxygen to ignite.

a reply to: 1947boomer

The requirements for the Fan Song guidance radar are such that there would have to be a container/trailer aboard with at least 600kW radar output (probably 1MW input power requirement) along with the launch rail for a 35' long SA-2. I would expect that a radar of that output might be noticed on local radars just from interference. This unit also wouldn't be easy to deep six even with a LASH ship and would certainly be discoverable after disposal unless the vessel made a run for deeper water before disposal. Further, if Iranians planned a revenge for the Vincennes, why go to all the complexity of a big missile with a high altitude intercept? Sit a few Jihadis at the end of the runway with Stingers/Stingerski's and take out an engine or two during take off.

You said that "if this had been a Navy SAM, both burns of the missile would have been the same color and brightness." That assumes that both motors would have been made of the same propellant. I haven't worked with Navy missiles in decades so I do not know modern flight envelopes and capabilities.

originally posted by: pteridine
a reply to: 1947boomer

The requirements for the Fan Song guidance radar are such that there would have to be a container/trailer aboard with at least 600kW radar output (probably 1MW input power requirement) along with the launch rail for a 35' long SA-2. I would expect that a radar of that output might be noticed on local radars just from interference. This unit also wouldn't be easy to deep six even with a LASH ship and would certainly be discoverable after disposal unless the vessel made a run for deeper water before disposal. Further, if Iranians planned a revenge for the Vincennes, why go to all the complexity of a big missile with a high altitude intercept? Sit a few Jihadis at the end of the runway with Stingers/Stingerski's and take out an engine or two during take off.

A lot of conspiracy theories, like many 9/11 ones, make this mistake. They act like some elaborate, difficult-to-pull-off scheme was the obvious way to execute an operation, when in reality there were simpler methods available.

It's worth noting that there was a ton of dredging and diving done in the area looking for, among other things, missile parts, and they found nothing. Surely they would've found such a large apparatus.

And sure, you can argue the FBI covered it up. But the FBI wasn't down there in diving suits doing the searching.

originally posted by: face23785

originally posted by: 38181
The fuel tank fuel sending unit wire theory is plausible however, I’ve seen military drop tanks with the same fuel sending units, sketchy as heck, thrown around and hooked up with enough JP-4 vapor to make you pass out, not explode. The electrical current going through the wires couldn’t even make a spark if you tried. Very low voltage.

I think the official explanation was that the energy didn't actually come from those wires, but came from a short in another part of the electrical system and arced into those wires from outside the tank at some point where the wires were damaged.

This was purely speculative though and they admitted there was no evidence of it. Which is funny because they dismissed every other theory on the grounds of "there was no evidence of it."

I feel like the final report is really inconclusive, and they should've just said that. They said the tank explosion is the most likely cause. There was circumstantial evidence that I think Zaph noted on page 1 of this thread, that one of the gauges was malfunctioning, indicating some kind of electrical problem. But electrical problems and odd gauge readings don't always cause explosions. The exact method of ignition was never determined from what I've seen.

There is no question that the center tank exploded. The question is why? No internal ignition source was ever identified. An incendiary pellet from a SAM warhead would certainly do the job.

And regardless of the ignition source, once the tank exploded, and the nose section was blown off there is no way the remaining piece of the aircraft would continue flying, much less climb, as the CIA would like us to believe.

Here's why: All the lift to keep an airplane in the air is generated by air flowing over the wings, due to forward flight speed. It turns out to be a fundamental fact of aeronautical engineering that the aerodynamic lift of a wing can be treated as if it is all concentrated at a spot 1/4 of the way back from the leading edge of the wing. In order for an aircraft to be stable in forward flight, the center of gravity of the aircraft has to be slightly forward of the center of lift. If the center of gravity was behind the center of lift, then both the lift generated by the wing and the weight generated by the mass of the aircraft would be operating to pitch the nose of the aircraft up. Pitching the nose up would increase the aerodynamic lift on the wing even more, and so on.

That's what would happen if you suddenly blew 20 feet off the nose of a 747. The center of mass would instantaneously move about 10 feet back behind the center of lift. The remaining piece of the aircraft would instantaneously start pitching up and keep doing so until the fuselage was pointing vertically. That would probably occur in less than a second. At that point, the remaining piece of aircraft would still be flying belly first forward at 400 mph. The deceleration force due to drag would be immense--probably well over 100 gs. The first thing that would happen in that scenario is that any passengers still belted in their seats would suddenly see the floor tipped up 90 degrees toward their faces. Their bodies would be suddenly decelerated at 100 gs into the seat while their heads would want to keep flying forward. In other words, heads would be snapped off, just as the NY ANG pilot reported. The second thing that would happen is that the jet engine pods would snap off. Engine pods are attached to the wing with fasteners that are much stronger than the human neck, but are designed to fail before the wing breaks. The engine pods did come off early in the sequence. The next thing that would happen is that whichever wing was slightly weaker than the other one would snap. On TWA 800, that was the left wing, the outer panel of which was discovered early in the debris field. At that point, the aerodynamic forces on the aircraft would be asymmetric and it would start to tumble and break up into smaller pieces.

Within a second of the nose coming off the aircraft it was no longer flying.

a reply to: 1947boomer

Yeah I guess I should've been more clear there. I agree it's obvious the tank exploded, it's just not obvious to me what caused the explosion. They have a guess that is plausible. I could have happened. But no proof that's what happened.

Agree the climb makes no sense if things happened the way they said it did.

I really don't know what happened. I just know them acting like the official explanation is so obvious--with no evidence--is fuel for conspiracy theories and allegations of cover ups. Sometimes it's better for the experts to just say "You know what, we're stumped on this one."

25 years later and they still haven't learned. Look at how many times the experts put their foot in their mouth during the pandemic.

a reply to: 1947boomer

well at least the passengers died nearly instantly.....owwch.

a reply to: JIMC5499

The center wing on 800 had just enough fuel to cover the bottom of the tank. It wasn’t full. And it was overheated badly at the time of the explosion. If it had been full, or not overheated so badly, I’d probably agree with you, but add those factors in and I can see the tank going up.

Never bought into the fuel tank as being the cause. It's hard enough to get jet fuel vapors to explode under controlled conditions.

a reply to: JIMC5499

The center fuel tank rested over the A/C packs. The A/C packs are fed by air bled off the engines, the air is very hot do to compression . It is estimated that the A/C packs reached a temp of 425 F literally cooking the tank TWA 800 had sat on the runway for an extended period of time on a very hot day. The A/C would have been running continuously

The center fuel was " Empty" Empty is a relative term as tthe tank contains residual fuel, up to 2 % of the full amount

This leaves plenty of room for fuel vapors to collect

As said Jet fuel, basically kerosene, is rated "COMBUSTIBLE" which means that under normal conditions will not generate sufficient vapors to flash Jet A has a flash point over 100 F (38 C) with an auto ignition point of 410 F (210 C)

Testing in the Arizona desert with fuel tanks found that the critical temp was 124 F - sufficient to create explosive vapors

As for ignition source it is believed a short in a fuel probe provided the energy to ignite the fuel vapor

www.youtube.com...

It is suspected that a crack or break in the wiring allowed current to leak over from a high voltage wiring

There is precedent in this theory - SWISS AIR 111 which crashed off Nova Scotia in 1999 do to an in flight fire

en.wikipedia.org...

An electric arc do to cracked wiring in the in flight entertainment system where current from high voltage electrical system leaked into the entertainment system sparked the fire

Energy of only 75 milli joules was found to create the spark to ignite fuel vapors

TWA 800 was one the first 747 built and was over 25 years old at time of the accident - the conditions for dried out and cracked wire existed. Because of the age it is also believed that the insulation between the A/C packs and the fuel tank
had broken down and allowed heat from the A/C to heat up the fuel in the tank

MY 2 cents worth ........

well at least the passengers died nearly instantly.....owwch.

a reply to: yuppa

Actually NO ...

When the cockpit section separated would have exposed the passenger cabin to wind of around 350 mph

At that speed arms and legs would flailed around would have been broken Any thing in the cabin not nailed down become
a projectile - think luggage from the over head bins flying around to create blunt force trauma

Anybody still alive would have perished when fuselage struck the ocean surface

Actually talked to a few of the divers who performed the body/.debris recovery

Water in area was shallow only about 100-125 feet so could be dove using conventional scuba or surface supply gear

originally posted by: firerescue

well at least the passengers died nearly instantly.....owwch.

a reply to: yuppa

Actually NO ...

When the cockpit section separated would have exposed the passenger cabin to wind of around 350 mph

That would assume a flow regime. Where would the exit flow be? There would be a good bit of buffeting, initially, but the likely immediate pitch-up and stall should have prevented 350mph air flow through the cabin.
Impact with the water killed anyone still alive. Heads departed and left empty faces. Bodies were stripped of clothing on impact except for well tied running shoes.

a reply to: firerescue

There was little evidence of having survived the initial explosion. Any that did would most likely have died when the fuselage broke apart before impact.

originally posted by: Zaphod58
a reply to: firerescue

There was little evidence of having survived the initial explosion. Any that did would most likely have died when the fuselage broke apart before impact.

That's what I was thinking. The g forces generated should've killed everyone, right?

What about those in the nose section? I imagine that wasn't quite as violent as what happened to rear section of the plane. Any chance they survived until impact with the water?

a reply to: face23785

There was a fireball through the cabin at the time of the explosion. Most of the remains that they were able to autopsy showed major damage from fire, with the rest showing dismemberment damage. IIRC, none showed any damage from altitude or signs of having survived the initial explosion.