Twa 800

[TonyC]

I think there was an Iran Air 747 that also blew up due the center tank issue.

The above cited report mentions a "special investigation of the May 9, 1976, explosion and in-flight separation of the left wing of an Iranian Air Force Model 747-131, as it approached Madrid, Spain, following a flight from Iran. Witnesses reported seeing a lightning strike to the left wing, followed by fire, explosion, and separation of the wing." The wreckage revealed evidence of an explosion that originated near a fuel valve installation in the left outboard main fuel tank.

 

[CitationLover]

It's unorthadox in an airplane that's neither certified nor stressed for it.

just curious (yes i do not like caps)....

at 90deg bank, what would you do with the ailerons/rudder keeping in mind you have the benefit of hindsight and not .5sec to do something. the poor fo is a scapegoat. all i said was he did a "standard" recovery in terms of basic aerodynamics.

 

[Typhoon1244]

TonyC,

I read the accident summaries and the excerpt from 90-1 you posted with great interest. I'm almost convinced that the official explanation for this incident makes sense, except for one major issue...but I'll come back to that in a second.

One thing I noticed in 90-1 is that the main issue they seem to have been concerned about was heat, not arcing.

POTENTIAL EXISTS FOR HEAT BUILD-UP IN -135 AIR REFUELING/BODY PUMPS WHEN THE PUMPS ARE RUN DRY. THIS HEAT BUILD-UP MAY CAUSE CONDITIONS OF AN EXPLOSIVE NATURE IN THE BODY TANKS.

Does anyone know whether or not the center tank pumps on N93119 were running as it climbed out on July 17th?

In any case, it's my understanding that for a given quantity of Jet-A to ignite, it must be heated and misted. I didn't think "fumes" were enough to cause an explosion, regardless of what the ignition source is. But when you read about all those lost Stratotankers...perhaps I'm mistaken.

Now, back to the major problem I have with the official explanation: if TWA 800 was brought down by an accidental explosion in the center tank, then what exactly did all those witnesses see?

I don't buy the CIA's "zoom climb" story. The aerodynamics and radar data don't support that. And the Agency's story about people being misled by the differing speed of sound and light doesn't apply to those who were looking up at 800 before the explosion.

As I said, eyewitness accounts are notoriously misleading, particularly when it comes to aircraft accident investigation. But are we really supposed to believe that two hundred people--including a handful of military pilots--all got it wrong?

 

[fastandlow]

And if you don't wanna take my word for it, try browsing through this FAA Notice regarding Fuel Tank Ignition Prevention Measures.

Including the KC-135 I mentioned from October 1989, this document lists are 13 civilian and 13 military accounts of fuel tank explosions. All but 4 were Boeing products.

1982: Air Canada DC-9 center wing fuel tank exploded on the ground during maintenance - - Dry running of pumps is the suspected cause........

Lot more instances that I was aware of, but the point remains that there are an awful lot of 747 series AC that have and are still flying and this scenario is just too rare, making me suspect something else. But this is based on intuition and limited experience with this equipment.

Assuming it was a fuel tank explosion, where does the oxygen come from? I'd think, even though it's not very volitile, the jet fuel vapors would displace any oxygen in a partially or even empty fuel tank.

 

[Typhoon1244]

"...In congressional testimony and in statements repeatedly made in the media, the NTSB leadership cited the loss of an Air Force 707 and three KC-135 air to air tanker aircraft, to fuel tank explosions as examples of mishaps similar to TWA Flight 800. Col. Dougherty’s office of the Air Force’s safety center says, “there is no record of a 707 loss and all three KC135’s were fueled with JP4, a fuel as volatile as automobile gasoline”. “Since switching to the military equivalent of...Jet-A fuel the Air Force has not had a problem.”

This is from Commander William Donaldson's report to the Congressional Subcommittee on Aviation two years after TWA 800 went down.

 

[Dangerkitty]

Just a little info from someone there!

AA Airbus flight crashed b/c the "God Pilot" F/O was trained that use of rudder to help regain the proper attitude is the proper procedure.

Who is claiming that the F/O was a "God Pilot"? What the heck does that mean?

He would have been trained because at the time American was training this. I know because I was a former TWA pilot who saw the video with 2300 other TWA pilots.

Let me get this straight. All 2300 TWA pilots saw the AAMP together and at the same time? (Question asked in a sarcastic manner.)

Many of us were amazed that AA was teaching this "unorthadox" and dangerous procedure.

I have been through the program as well. None of what the AAMP taught is, was or will ever be dangerous or unothadox. If it was or had been then why did the FAA as well as other airlines use and still use all and parts of the program to train pilots? Can you answer that for me?

As far as 800, I was flying back from KBOS to KJFK that evening. It didn't just blow up. I too, like many others saw the "streak" heading skyward from the ocean.

It has been shown many times that that "streak" was most likely TWA 800 flying in a near vertical manner after exploding with the wings still attached. The streak you saw was probably the plane itself.

Being typed on the 747 and very familiar with the systems of the 747, I am sure that it didn't blow up on it's own. Go ahead and throw a match on a pool of jet a. The match will be extingushed. The fuel must be vaporized to attain the flashpoint for ignition.

That statement alone shows you have no clue what you are talking about. After TWA 800 Boeing came out with an AD for all operators of the B-747, B-767 and I think the B-757 to leave a certain amount of fuel in the center fuel tank to prevent such an explosion that happened on TWA 800.

 

[TonyC]

One thing I noticed in 90-1 is that the main issue they seem to have been concerned about was heat, not arcing.Does anyone know whether or not the center tank pumps on N93119 were running as it climbed out on July 17th?

In any case, it's my understanding that for a given quantity of Jet-A to ignite, it must be heated and misted. I didn't think "fumes" were enough to cause an explosion, regardless of what the ignition source is. But when you read about all those lost Stratotankers...perhaps I'm mistaken.

Assuming it was a fuel tank explosion, where does the oxygen come from? I'd think, even though it's not very volitile, the jet fuel vapors would displace any oxygen in a partially or even empty fuel tank.

From the FAA Notice:

"Evidence indicates that as the airplane was
climbing near 13,800 feet mean sea level (msl), an in-flight explosion occurred in the center wing fuel tank (CWT). (The flight engineer from the previous flight remembered having left about 300 pounds, or about
50 gallons, of fuel in the approximately 13,000 gallon capacity tank. The recovered fuel gauge indicated slightly more than 600 pounds (about 100 gallons) of fuel remaining in the CWT.) The CWT was nearly empty."

"Portions of the airplane have been reconstructed, including the CWT, the passenger cabin above the CWT, and the air conditioning packs and associated ducting beneath the CWT. The reconstruction thus far shows outward deformation of the CWT walls and deformation of the internal components of the tank that are consistent with an explosion originating within the tank. Airplane parts (includes portions of the fuselage structure from above, air conditioning packs and ducting from below, wing structure from both sides, all tires from behind, and numerous components that included the large fiberglass water and cargo fire extinguisher containers from forward of the CWT) from in and around the CWT recovered and identified to date contain no evidence of bomb or missile damage."

"Fuel tank explosions require an energy source sufficient for ignition and temperatures between the lower explosive (flammability) limit (LEL) * and upper explosive limit (UEL), which will result in a combustible mixture of fuel and air.

* (Marks' Standard Handbook for Mechanical Engineers, Eighth Edition, states, ``The lower and upper limits of flammability indicate the percentage of combustible gas in air below which and above which flame will not propagate. When a flame is initiated in mixtures having compositions within these limits, it will propagate and therefore the mixtures are flammable.'' Marks' states further, ``The autoignition temperature of an air-fuel mixture is the lowest temperature at which chemical reaction proceeds at a rate sufficient to result eventually (long time lag) in inflammation.'' In the TWA800 CWT, the LEL was about 115 deg.F, and the autoignition temperature was about 440 deg.F.)"

"However, a 1990, Society of Automotive Engineers technical paper comments, ``. . . if the ignition source is sufficiently strong (such as in combat threats), it can raise the fluid temperature locally and thus ignite a fuel that is below its flash point temperature. This is particularly true with a fuel mist where small droplets require little energy to heat up.''

"... on August 26, 1996, Boeing conducted flight tests with an instrumented Model 747 airplane that carried about the same small amount of fuel in the center wing tank as that carried aboard TWA800. All three air conditioning packs were operated on the ground for about 2 hours to generate heat beneath the CWT. The airplane was then climbed to an altitude of 18,000 feet msl. The temperature of the fuel in the center tank of the test airplane was measured at one location, and the air temperature within the tank was measured at four locations. In this test, the fuel-air mixture in the CWT ullage was stabilized at a temperature below the LEL on the ground. However, as the airplane climbed, the atmospheric pressure reducing the LEL temperature and allowing an explosive fuel-air mixture to exist in the tank ullage."


Now, fastandlow, you have touched on a very important concept, that of the existence of oxygen in the tank. No, fuel vapors do not displace oxygen. At the altitude the explosion occurred, there was more than sufficient oxygen to sustain an explosion. But there is a recommendation to equip airplanes with systems to replace oxygen with nitrogen.

"Without oxygen in the fuel-air mixture, the fuel tank ullage could not ignite, regardless of temperature or ignition considerations. The military has prevented fuel tank ignition in some aircraft through the creation of a nitrogen-enriched atmosphere (nitrogen-inerting) in fuel tank ullage, there by creating an oxygen-deficient fuel-air mixture that will not ignite. Although this technology could be applied to civil aircraft, there are no transport category airplanes of which the Board is aware that currently incorporate nitrogen-inerting systems to reduce the potential for fuel tank fires and explosions."


I could go on and on copying and pasting, but you really should take the time to read the whole thing yourself. It's quite educational.

Now, back to the major problem I have with the official explanation: if TWA 800 was brought down by an accidental explosion in the center tank, then what exactly did all those witnesses see?

...

As I said, eyewitness accounts are notoriously misleading, particularly when it comes to aircraft accident investigation. But are we really supposed to believe that two hundred people--including a handful of military pilots--all got it wrong?

I don't know what they all saw, or even what one of them saw. I do find eyewitness testimony to be, at best, suspect. Given that the airplane has been almost entirely reconstructed, and that the physical evidence is overwhelming, I believe the eyewitnesses, once again, got it wrong.

 

[atrdriver]

That statement alone shows you have no clue what you are talking about. After TWA 800 Boeing came out with an AD for all operators of the B-747, B-767 and I think the B-757 to leave a certain amount of fuel in the center fuel tank to prevent such an explosion that happened on TWA 800.

No, the FAA has NEVER issued AD's that were either unnecessary or suspect for some reason. There are a lot of inconsistancies in the TWA800 case. If you want to believe that it blew up by itself, fine. There are still a LOT of people,and will always be a lot of people, who believe otherwise.

 

[TonyC]

Ladies and Gentlemen:


I apologize for any misleading statements I may have made above. Please disregard all of my previous comments on this subject.

I have just been informed via PM that somebody knows somebody else at the CIA, in fact two somebodies at CIA that don't even know each other, that both know for a fact TWA 800 was shot down.


Sorry for the inconvenience!

 

[Typhoon1244]

Well, that settles it. I hope we can all put this behind us...

 

[350DRIVER]

no apology needed.

Jeez, after reading brightspark's well thought out responses I assumed the entire group here would for sure be convinced it was a problem with the fuel tank..

bummer- just when you had everyone certain this happens !.

3 5 0

 

[C601]

You put 50 people in a room, they give you 50 different answers as to why it blew up..., my belief is we will probably never know the true facts......too many liars and black mailers out there. They tell you what you want to hear to keep you quite.

There is more questions then factual answers, none of us where there, all we have is info passed on from one person to another ... kinda defeats the whole purpose and most likely a complete waste of time,kinda like this thread

 

[EagleRJ]

So the center wing tank is filled with a mix of air and kerosene fumes, which by the NTSB's own findings do not become flammable until after takeoff (and discounting the fact that the day the NTSB's test was conducted was 16 degrees warmer than July 17th). Somehow, a large amount of flammable vapors build up, even though the ullage was right at or below the critical temperature. Then a spark ignites the mixture- possibly from the CWT scavange pump, even though the pump was not running at the time, and was recovered and found not to have any problems. The resulting explosion is violent enough to blow the forward half of the fuselage off and eject debris out the right side which radar estimates is travelling at 2000 FPS.
The majority (98%) of the CWT is then recovered- all in the easternmost part of the debris field. Highly unlikely.

The NTSB's report details an experiment they performed with a scale model of the 747's CWT to investigate the nature of fuel vapors. When they heated the Jet-A to the vapor point and tried to ignite it, nothing happened. They eventually had to add propane and hydrogen to get a reaction, because the kerosene fumes would do nothing more than burn off and then self-extinguish.
You have to realize that when fuel vapors burn, it is a low velocity explosion. It's more of a "whump" that may deform or even rupture the tank, but can't do the kind of damage that was observed on the TWA 800 airframe. Much of the physical evidence, radar data, and eyewitness accounts, is indicitive of a high velocity explosion. That cannot be caused by fuel vapors of any kind- only high explosives.

Interesting side note:
Does anyone remember that Muslim wall calendar found in Europe that was in the news just after 9/11? It showed an airliner crashing in flames near New York City, and the media suggested it showed that the 9/11 plot was widely known enough to allow calendars to be printed even before the attack.
The calendar definitely depicts New York City- the Statue of Liberty is visible in the background. Two interesting things though: the airliner is a 747, and it is shown crashing into the water! Hmmm....

 

[EagleRJ]

There is more questions then factual answers, none of us where there, all we have is info passed on from one person to another ... kinda defeats the whole purpose and most likely a complete waste of time,kinda like this thread

True, but I think it's our duty as pilots to see the true cause for this crash determined, and the associated threat addressed. To date, the investigation has been the strangest and most unconvincing accident investigation in history.
The book First Strike makes a good point about the evidence. It mentions Occhams's Razor- the idea that the simplest explanation is usually the correct one. So much of the evidence in this crash points to a missile attack, but the government seems determined to pursue far-fetched elaborate theories to avoid acknowledging it.

If I had lost a loved one on the plane, you can bet I'd be determined to know the cause of the crash! I think the family members have a right to be upset at how the investigation has been conducted so far.

 

[atrdriver]

One of the biggest questions that was always left in my mind was why did the CIA produce the video of what supposedly happened. The NTSB obviously has the capability to do so, as does the FBI. Why, AFTER they supposedly determined that foul play was not involved, was the CIA commissioned for the video?

 

[dash8driver]

this sounds like a job for Mythbusters!

 

[Axel]

this sounds like a job for Mythbusters!

Or the Dallas police.

 

[Dangerkitty]

No, the FAA has NEVER issued AD's that were either unnecessary or suspect for some reason. There are a lot of inconsistancies in the TWA800 case. If you want to believe that it blew up by itself, fine. There are still a LOT of people,and will always be a lot of people, who believe otherwise.

ATRDRIVER,

I used a poor choice of words. Boeing issued information asking operators to not run the center tanks dry and to keep a certain amount of Jet-A in them. I never said anything about the FAA but since I stated AD I guess thats what was implied. Sorry for the confusion.

 

[KigAir]

Come on...The F-117A was in sqadron service for almost 10 years before anyone outside the program knew that it existed. Don't tell me that the government can't keep a secret if they want it kept.

I think there is a slight difference between working a classified project and being involved in a friendly fire incident.

 

[SiuDude]

See how quickly I'm adapting to living in Tennessee?

Sigh....
Everyone knows that "y'all" is singular, while "y'alls" is plural.