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TWA800 Fuel Tank Question  
User currently offlineAAden From United States of America, joined Jan 2006, 835 posts, RR: 0
Posted (5 years 2 months 3 weeks 15 hours ago) and read 6735 times:

I was reading a report on TWA800; am I correct that the fuel tank exploded because of a live wire? The explosion was caused by the lack of fuel in the tanks.

I don't understand why there wouldn't be any fuel in the tanks if it was crossing the atlantic.

Can anybody sum up what happened?

I'm not looking for a conspiracy, I just want the technical stuff.

123 replies: All unread, showing first 25:
 
User currently offlinePropilot83 From United States of America, joined Jan 2001, 596 posts, RR: 0
Reply 1, posted (5 years 2 months 3 weeks 15 hours ago) and read 6735 times:

TWA-800 was a Boeing 747-200. After watching a documentary on the accident, I learned that fuel vapors were in the center fuel tank and that an air conditioning unit pack was located directly underneath the center fuel tank. Investigators had concluded that after the plane sat on the tarmac at JFK before departure, the weather was very hot that July day, and the air conditioning packs were running full blast to cool the interior of the plane, and so in doing this, the air conditioning unit underneath the center fuel tank became very hot, and after take-off, some kind of electrical wire running through the empty center fuel tank caused a spark and the fuel vapors ignited causing a massive explosion from the center fuel tank and causing the plane to break apart. The Air conditioning unit might have had something to do with the explosion and the wiring of the center fuel tank. As far as fuel not being loaded in the center fuel tank on that TWA-800 flying across the Atlantic, well perhaps the flight was only about 3,500 miles or so, and the Boeing 747-200 can fly quite a distance without the need of having fuel in the center fuel tank, I believe that the center fuel tank is used for long haul flights that are near 5,000 miles + or for emergency reserve fuel. I am not sure yet if the NTSB did eventually find the "electrical wire" that caused the spark in the center fuel tank.

User currently offlineSEPilot From United States of America, joined Dec 2006, 6875 posts, RR: 46
Reply 2, posted (5 years 2 months 3 weeks 12 hours ago) and read 6702 times:

I knew an ex-PA 747 pilot when this happened (he was our local flight instructor); he said that the standard procedure would be to have a small amount of fuel in the center tank and you would use that on takeoff; at just about the time the plane exploded you would switch tanks. He was convinced there was something in the tank switching mechanism that sparked and caused the explosion. The NTSB was unable to identify the precise wire or function that caused the explosion, and I remain unconvinced by the official explanation. I am also dubious of the various conspiracy theories as well. But what the eyewitness saw does not square with the official explanation.


The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineFr8Mech From United States of America, joined Sep 2005, 5388 posts, RR: 14
Reply 3, posted (5 years 2 months 3 weeks 10 hours ago) and read 6677 times:



Quoting SEPilot (Reply 2):
he said that the standard procedure would be to have a small amount of fuel in the center tank and you would use that on takeoff;

Not too sure about that. Standard procedure, on just about any aircraft, is tank-to-engine on take-off and landing. You would switch to the center tank after take-off and start burning the center tank to all the engines (as I recall). When the center is empty, you burn the inboards to all the engines. When the inboard quantities matched the outboard quantities, including the reserve tank(s), you burn tank-to-engine. As I recall, the override/jett pumps in the center tank will only take the tank down to 2 or 3 thousand pounds. It's up to the scavenge pump to deal with the rest. And all it does is pump the fuel into the #2 main.

Quoting SEPilot (Reply 2):
He was convinced there was something in the tank switching mechanism that sparked and caused the explosion.

Tank switching or selection is performed by pump manipulation and use of the crossfeed valves. As I recall, on the B747-classic, none of these wires run internal to the tank. The only wires I recall seeing in the center tank, or any tank, for that matter, were FQIS (fuel quantity indication system) wiring.



When seconds count...the police are minutes away.
User currently offlineDispatchguy From United States of America, joined Jan 2006, 1249 posts, RR: 2
Reply 4, posted (5 years 2 months 3 weeks 10 hours ago) and read 6678 times:



Quoting AAden (Thread starter):
I don't understand why there wouldn't be any fuel in the tanks if it was crossing the atlantic.

The B747-100, for the relatively short flight to CDG from JFK, wouldnt need enough fuel onboard to require the center fuel tank to be loaded.

Every airliner has specific fuel loading and distributions. So if the fuel is X, we already know how that X will be divided up into the various fuel tanks on the aircraft. And, for the fuel load required on TWA800, the dispatch fuel didnt require loading of fuel in the center tank.

The fuel load was 176.6, and the distribution for this would be:

Mains 1 & 4 - Full (24.6 each)
Mains 2 & 3 - 60.1 each
Reserve 1 & 4 - Full
CWT - Empty



Nobody screws you better than an airline job!
User currently offlineEuclid From South Africa, joined Apr 2005, 372 posts, RR: 0
Reply 5, posted (5 years 2 months 3 weeks 6 hours ago) and read 6641 times:



Quoting Fr8Mech (Reply 3):
The only wires I recall seeing in the center tank, or any tank, for that matter, were FQIS (fuel quantity indication system) wiring.

From what I remember from the programs I have seen about this crash, the only wires in the tank were for the fuel indicators, as quoted above. These were all low current wires that would not be able to spark due to the low current carried by them. No high current wires were routed through the tank due to the danger of sparking.

However, the wiring in this plane was found to be in a very bad state, and it is assumed that a spike through one of the high current wires elsewhere found its way to the wiring in the fuel tank, causing it to spark.

The evidence for this comes from what I believe was the last words spoken on the CVR: "Look at that crazy fuel flow indicator", suggesting that something in the wiring had gone haywire.


User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2546 posts, RR: 24
Reply 6, posted (5 years 2 months 3 weeks 6 hours ago) and read 6636 times:

As well as FQIS wiring, which is low voltage, the boost pumps, situated inside each tank, require electrical power, which is a much higher voltage. However these pumps have flame suppression systems and so were discounted as a probable cause by the NTSB. A short circuit in the FQIS wiring, leading to a high voltage, was deemed to be the most likely source of ignition.

The main point about TWA800 is that the centre wing tank was empty, apart from fumes. One recommendation made after the accident was to always refill the centre wing tank with cold fuel before each departure. This avoids the problem of highly combustible fuel vapours which only need a spark to ignite. Much harder to ignite a tank of liquid jet fuel.

[Edited 2009-06-02 09:39:23]


The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineJetlagged From United Kingdom, joined Jan 2005, 2546 posts, RR: 24
Reply 7, posted (5 years 2 months 3 weeks 6 hours ago) and read 6623 times:



Quoting Euclid (Reply 5):
The evidence for this comes from what I believe was the last words spoken on the CVR: "Look at that crazy fuel flow indicator", suggesting that something in the wiring had gone haywire.

Fuel flow indication is entirely seperate from tank quantity indication. The fuel flow transducer is in the engine itself, nowhere near the centre tank. As well as the engine fuel flow indicator it is also connected to the engine fuel used indicator (on the F/E panel), but this is not connected to the fuel quantity indication system either.



The glass isn't half empty, or half full, it's twice as big as it needs to be.
User currently offlineFr8Mech From United States of America, joined Sep 2005, 5388 posts, RR: 14
Reply 8, posted (5 years 2 months 3 weeks 5 hours ago) and read 6603 times:



Quoting Euclid (Reply 5):
The evidence for this comes from what I believe was the last words spoken on the CVR: "Look at that crazy fuel flow indicator", suggesting that something in the wiring had gone haywire.

The fuel flow indication system is seperate from the FQIS, and on the Classic was notoriously erroneous, though most of those issues were on the ground.

Quoting Jetlagged (Reply 6):
As well as FQIS wiring, which is low voltage, the boost pumps, situated inside each tank, require electrical power, which is a much higher voltage.

The boostpumps are in the tank, but the wiring is external. Is it possible that a boost pump can produce a spark? Yes, but unlikely due to design, so I've been led to believe.



When seconds count...the police are minutes away.
User currently offlineSoon7x7 From , joined Dec 1969, posts, RR:
Reply 9, posted (5 years 2 months 3 weeks 1 hour ago) and read 6540 times:

The current theory on the TWA800 is speculative at best, no one knows for sure the absolutes that brought down the plane. The center wing tank is about the size of a living room, 20'x20'x7'high. The inside of the tank has many baffles or walls which by design are also the wing spars. All fuel sensors and scavange pumps are of the low voltage type. The fuel itself being a highly oil base medium, helped to preserve the integrity of the wire, sealants and the condition of the aluminum inside the tanks...(virtually no corrosion, even after thirty years).The center keel beam runs throught it as well. In the tank that night were about 50 US gallons of JetA. Even with the ambient heat resulting from the three ac packs,...the fuel must be atomized or misted before it can become explosive. 50 gallons of JetA in a 20x20x7 foot room is not volitile enough to totally desomate a 850,000lb ship. Boeing has built in all precautions for heat build up and appropriate venting as the plane was designed for all environments, including desert environments. KC-135's carry 75,000 lbs of fuel and during desert storm operations while being based in hot environments that far exceeded Long Islands that day. Someday the case will be unclassified and it will be interesting to follow up on that event. Pieces of that plane are still washing up on New York beaches as about 4 tons of airframe still remain underwater...

User currently offline474218 From United States of America, joined Oct 2005, 6340 posts, RR: 9
Reply 10, posted (5 years 2 months 3 weeks ago) and read 6530 times:



Quoting Fr8Mech (Reply 8):
The boostpumps are in the tank, but the wiring is external.

Many boost pumps have the wiring inside the tank. Examples in the following:

http://www.parker.com/literature/Nic...for%20Literature/Brochure_Fuel.pdf

Quoting Fr8Mech (Reply 8):
Is it possible that a boost pump can produce a spark? Yes, but unlikely due to design, so I've been led to believe.

I have seen boost pumps with holes burned in the housing which suggests alot more than sparks.


User currently offline113312 From United States of America, joined Apr 2005, 571 posts, RR: 1
Reply 11, posted (5 years 2 months 2 weeks 6 days 23 hours ago) and read 6524 times:

I taught systems on the B747 for years and have never accepted the official conclusion. B747s have operated for decades in hot conditions around the world with little or no fuel in the center tank without exploding. The high pressure boost pumps in all of the fuel tanks use three phase alternating current so that they can impart rotary motion without the use of commutator brushes. Thus, these type of motors are hard wired and produce no sparks. In addition, the electrical portion of these pumps are in a dry cavity and not exposed to fuel or fuel vapors.

The only electrical components actually in the fuel tank are the fuel quantity sensors. These are capacitance type transduces and are powered by low voltage and very low current. THey also should not be able to produce sparks.

Contrary to what was stated by one of the other posters, the normal fuel management for a -100 series is tank-to-engine for start, taxi, and takeoff. If fuel were in the center aux tank, it would only be used once the aircraft was established in climb. Fuel is not normally carried there unless needed by the flight plan. If a little residual was there and not required, it would most likely have just been left alone. It certainly would not have been used in that part of the climb.

No matter, opening or closing of valves should not have produced an explosion. The NTSB finding, in my opinion, was in the absence of a better explanation and expedient to close the case. They never proved the case beyond a reasonable doubt.


User currently offlineFr8Mech From United States of America, joined Sep 2005, 5388 posts, RR: 14
Reply 12, posted (5 years 2 months 2 weeks 6 days 22 hours ago) and read 6498 times:



Quoting 474218 (Reply 10):
Many boost pumps have the wiring inside the tank. Examples in the following:

Right, but the B747-Classic does not and this is what we are discussing. I've worked on aircraft with boost pump wiring in the tank.

Quoting 113312 (Reply 11):
No matter, opening or closing of valves should not have produced an explosion. The NTSB finding, in my opinion, was in the absence of a better explanation and expedient to close the case. They never proved the case beyond a reasonable doubt.

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When seconds count...the police are minutes away.
User currently offlineViscount724 From Switzerland, joined Oct 2006, 25117 posts, RR: 22
Reply 13, posted (5 years 2 months 2 weeks 6 days 21 hours ago) and read 6475 times:



Quoting Propilot83 (Reply 1):
TWA-800 was a Boeing 747-200.

It was a 747-100 (the aircraft below), not a -200.


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User currently offlineTUNisia From United States of America, joined Aug 2004, 1844 posts, RR: 5
Reply 14, posted (5 years 2 months 2 weeks 6 days 20 hours ago) and read 6468 times:

I still have many doubts about the governments claims regarding TWA 800.

Stuff like this...

http://whatreallyhappened.com/RANCHO/CRASH/TWA/BASS/bassett.html

still makes me wonder...



Someday the sun will shine down on me in some faraway place - Mahalia Jackson
User currently offlinePropilot83 From United States of America, joined Jan 2001, 596 posts, RR: 0
Reply 15, posted (5 years 2 months 2 weeks 6 days 15 hours ago) and read 6414 times:

A missile did not bring down TWA-800. If a missile had actually shot the plane down, then the NTSB would not have had the capability to re-build 90 feet of the center of the plane again. You know there are always going to be rumors, theories, and a bunch of bullsh*t when events like this occur. If a missile had actually shot the plane down, the explosion would have been so big that the debris would have been no larger than the size of a car. And you know what else, the government wouldnt have kept this a secret either, because some time back in the 1970's to 1980+'s, the U.S. Navy accidently shot down an Iranian Airbus airliner in the middle east with an F-14 Tomcat. The Navy thought that it was an Iranian enemy fighter plane it was intercepting, instead later on when it was already too late.....figured out it was a bunch of innocent Iranian's flying on an Airbus jetliner. Why didnt the government keep that a secret? People will say that TWA-800 was shot down by a missile, just for the purpose of making money. Its all about money, they will print magazines, newspapers, books, a bunch of other crap just to get their pockets full of cash on some rumor out of nowhere. It is a fact, that TWA-800 was not shot down by a missile, it was a center fuel tank explosion due to some faulty electrical wiring in or near the center fuel tank with fuel vapors, or fumes in the empty tank....PERIOD!

User currently offlinePhilSquares From , joined Dec 1969, posts, RR:
Reply 16, posted (5 years 2 months 2 weeks 6 days 15 hours ago) and read 6413 times:



Quoting Propilot83 (Reply 15):
It is a fact, that TWA-800 was not shot down by a missile, it was a center fuel tank explosion due to some faulty electrical wiring in or near the center fuel tank with fuel vapors, or fumes in the empty tank....PERIOD!

Could you provide the data that allows you to be the authority on this matter? I have over 7000 hours in the classic and the entire sequence of events just does not make sense. While I don't subscribe to the missile theory, I certainly don't subscribe to the center fuel tank theory either.

Aircraft don't just blow up in the sky. The theories about the residual heat from ground operations and the shorting of the electrics just makes no sense.


User currently offlineDH106 From United Kingdom, joined Jun 2005, 626 posts, RR: 1
Reply 17, posted (5 years 2 months 2 weeks 6 days 14 hours ago) and read 6405 times:



Quoting Propilot83 (Reply 15):
A missile did not bring down TWA-800. If a missile had actually shot the plane down, then the NTSB would not have had the capability to re-build 90 feet of the center of the plane again....... ..... If a missile had actually shot the plane down, the explosion would have been so big that the debris would have been no larger than the size of a car.

This is undoubtably true, and though I don't necessarily subscribe to the missile theory I agree with PhilSquires and others that the facts as stated just don't add up, and like to play devil's advocate and explore all the possibilities:-

What about a missile that didn't explode - either through failure or through a dummy warhead..This could leave the 'residue' alluded to in TUNisia's link (reply14) unburnt and if it struck the 747 in a critical area around the center fuel tank it could quite possibly set off the explosion in that tank that set in train the structural break up.



...I watched c-beams glitter in the dark near the Tanhauser Gate....
User currently offlineJwenting From Netherlands, joined Apr 2001, 10213 posts, RR: 18
Reply 18, posted (5 years 2 months 2 weeks 6 days 11 hours ago) and read 6383 times:



Quoting PhilSquares (Reply 16):
Aircraft don't just blow up in the sky.

Tell that to the next of kin of the A330 that crashed monday...
Accidents happen.

TWA800 like all of them was a complex combination of unlikely events and failures that when combined in the right order and under the right environmental conditions led to catastrophe.
Had there been a bit more fuel in that tank, had the short happened at a somewhat different altitude, had the aircraft not been delayed (causing the airco unit to be hotter than normal at that stage during the flight), etc. etc.etc., it would likely not have crashed.



I wish I were flying
User currently offlinePhilSquares From , joined Dec 1969, posts, RR:
Reply 19, posted (5 years 2 months 2 weeks 6 days 10 hours ago) and read 6375 times:



Quoting Jwenting (Reply 18):
Tell that to the next of kin of the A330 that crashed monday...
Accidents happen.

So, you have the AF crash all figured out! Amazing!!! Perhaps you need to re-read my post. I never did say accidents don't happen, what I did say was aircraft just don't explode in flight because of the vapor it the CW Tank and a spark.


User currently offlineSoon7x7 From , joined Dec 1969, posts, RR:
Reply 20, posted (5 years 2 months 2 weeks 6 days 10 hours ago) and read 6367 times:



Quoting Propilot83 (Reply 15):

Just for the record...several types of missiles exist that have the potential of destroying a 747 with out even contacting the airfame...proximety missiles,etc. They don't have to be large at all, in fact very small as the airframe just has to be compromised and the breakup sequence will do the rest. Thats what can cause 50 gallons of JET A to mist, then result in a massive explosion. Travelling at 350MPH with exposed 1/16 th aluminum skin doesn't leave much to the imagination. The plane will peal apart like a banana. On the other hand, most of us, if not all of us...if anyone here believed the CIA climb video that a 747, despite cg. change and all the other crap...climbed another 3200 feet after the front 1/3 of the fuselage departed the airframe, and would have most definetely resulted in the shut down of engines #2 and #3 due to FOD ingestion, then you don't know as much about planes as you think. I can't imagine any aviatior on this site believes the CIA cartoon.
If a center wing tank JUST blew up then design flaws exist...the fleet should have been GROUNDED!...not only were they never grounded but had it been a design flaw, the same scenario would have played out many other times on many other 747's in many parts of the world. The fuel tank obviously blew, in fact ALL the fuel tanks blew....the wings opened up from explosive forces, not from aerodynamic forces although that didn't help either. The notion that other theories exist for the sake of making a buck is silly...Americans will try and make a buck on anything...thats what is great about America...right or wrong.


User currently offlineDH106 From United Kingdom, joined Jun 2005, 626 posts, RR: 1
Reply 21, posted (5 years 2 months 2 weeks 6 days 9 hours ago) and read 6361 times:



Quoting Soon7x7 (Reply 20):
..........climbed another 3200 feet after the front 1/3 of the fuselage departed the airframe, and would have most definetely resulted in the shut down of engines #2 and #3 due to FOD ingestion,

Power isn't the issue, a 747 travelling at 350mph has a LOT of inertia. After the nose was blown off, the resulting gross rearwards shift in the CG would most definitely cause a pitch up. If you calculate the aircraft's kinetic energy at 350mph and then hypothosise a scenario where the aircraft then pitches up and climbs while the speed decays on the effects of gravity alone (converting it's kinetic energy into extra height or 'potential' energy) then the height gain would be of the order of 4000ft (neglecting the effects of drag etc - but then all 4 engines wouldn't instantly cease developing thrust either). I think 3200ft is entirely reasonable.



...I watched c-beams glitter in the dark near the Tanhauser Gate....
User currently offlineSoon7x7 From , joined Dec 1969, posts, RR:
Reply 22, posted (5 years 2 months 2 weeks 6 days 7 hours ago) and read 6341 times:



Quoting DH106 (Reply 21):

On the basis of aerodynamic drag alone, all other forces will rapidly be cancelled out, drag and gravity will immediately overpower all other forces...an open cylinder, 20 feet wide by 26 feet high, minus 50% power, would create enourmous negative g's while rapid deceleration would negate any possibilty of a 3200 foot climb. Two friends of mine that were airborne in the area, one facing the event head on stated to me that upon the explosion the aircraft as much as stopped in the air and DROPPED...no climb existed...I've got over 5,000 hours flying non powered aircraft...aerdynamics are fairly important to me...a possible climb of 320 feet by inertia, figuring in all the other perameters, I'd accept that, but not 3,200 feet. Given the condition of the aircaft post nose separation...Virtually imossible.


User currently offlineFaro From Egypt, joined Aug 2007, 1540 posts, RR: 0
Reply 23, posted (5 years 2 months 2 weeks 6 days 4 hours ago) and read 6301 times:



Quoting Soon7x7 (Reply 9):
Someday the case will be unclassified and it will be interesting to follow up on that event. Pieces of that plane are still washing up on New York beaches as about 4 tons of airframe still remain underwater...

Interesting, I wasn't aware that there remained a "case" and that it was being kept away from the public eye. Is there any official notification of such retention, and by which public authority? How much more time remaining to declassification?

Faro



The chalice not my son
User currently offlineMoose135 From United States of America, joined Oct 2004, 2312 posts, RR: 10
Reply 24, posted (5 years 2 months 2 weeks 6 days 4 hours ago) and read 6295 times:



Quoting Faro (Reply 23):
I wasn't aware that there remained a "case" and that it was being kept away from the public eye.

Officially, the FBI ended its investigation years ago, stating "No evidence has been found which would indicate that a criminal act was the cause of the tragedy of TWA flight 800." However, during the early stages of the NTSB investigation, the FBI collected large amounts of recovered materials, which they examined for evidence of a crime. For the most part, they did not release reports about those materials, nor have they turned over the materials to the NTSB or any other party, despite repeated lawsuits and Freedom of Information act requests.



KC-135 - Passing gas and taking names!
25 DH106 : Yeah...... fair point about the drag. So where does CIA state the data for the reconstruction come from - was the FDR functional after the nose seper
26 Moose135 : No, the CVR and FDR both stopped working at the time of the initial blast. The CIA made up the video in order to attempt to show that the eyewitnesse
27 Post contains images Soon7x7 : The CIA data was constructed from Key Eyewitnesses. Some data from local ATC,(but not all). Statements from other pilots that were airborne. No data
28 Propilot83 : I dont think there was a dummy missile, there was actual reports indicating that the USS Normandie cruiser was in the area off the coast of New York,
29 Moose135 : What was your question about that shootdown? BTW, it wasn't an F-14 that shot it down, as you stated in Reply 15, it was shot down by missiles from t
30 Soon7x7 : Your 100% correct, anything is possible. N93119 made its way around and was maintained by many, I believe Iran actually had two TWA 747's for a while
31 Soon7x7 : Moose...I never got a chance to reply to that segment, you stole my thunder...I remember that event clearly and I also remember that the were pissed,
32 KE7JFF : I think the FBI and the NTSB did the best job with the limited information provided by witnesses, the wreckage, and the CVR/FDR. I don't think it was
33 Soon7x7 : Me thinks the NTSB should have been left alone to spearhead the investigation rather than the FBI and CIA. To me they seem to be sort of out of juras
34 Jwenting : CIA was almost certainly only called in to provide some technical expertise other agencies didn't posess. They're barred by law from operating on the
35 Faro : One question: in the below thread post, does the NTSB have a *right* to any supplemental reports or materials as have been requested from the FBI? We
36 Soon7x7 : The way it worked before TWA800 was the NTSB would obviously be called in to kick off any and all plane incidents and accidents. If they suspected fo
37 PhilSquares : Let me play devil's advocate. What did the past CEOs know about auto manufacturing? Doesn't seem to me like it could make things worse!
38 SEPilot : I do not know 747 procedures, but this pilot had thousands of hours in the 741. I may have misremembered some of what he said, but the gist of it I r
39 Soon7x7 : Yeh, it's nothing new here in the states,...what ever happened to job qualifications? Gone are the days where you worked your way up the ladder as a
40 SEPilot : And let the Peter Principle run amok.
41 Jetlagged : So you think a spark in a tank full of highly combustible fuel vapour couldn't cause it to explode? Temperature is also important because it affects
42 SEPilot : The point is that jet fuel vapor in normal circumstances is not highly combustible. It must be within a fairly narrow band of concentration, and this
43 PhilSquares : No I don't. The temp in the CW tank doesn't get that hot and there was no reason to think it would have been hot on this flight. In fact, the sister
44 Rwessel : At 13,000ft, the air pressure is a hair under 9psi. And didn't someone blow up a 737 center tank (on the ground) with a very low voltage spark with i
45 PhilSquares : My mistake. At 18,000 the PSI is half of the sea level pressure. I provided you all the fuel tank explosions. Again, there have been NO fuel tank exp
46 Post contains links and images SXDFC : From what I remember hearing on the news, and reading in books the Boeing 747-131 N93119 came in from Athens,Greece which is a 10+ hour flight from AT
47 Lowrider : APU fuel on the classic comes from the #2 (L Inboard) Main.
48 Soon7x7 : A full tank has less of a chance of exploding than one that is partially full. In the case of N93119, the night of July 17,1996, about 50 US gallons
49 Post contains images Soon7x7 : As an aviator...can you or anyone here actually think that this has the ability to climb 3,200feet with a 50% power reduction?...forget the drag and
50 Viscount724 : To the best of my memory, that is not correct. I can recall various individual carrier groundings of MD-80s for various inspections where they had no
51 Soon7x7 : Your correct, I remember that immediate mandatory inspections were to be performed but a blanket grounding was not imposed...my mistake...j
52 Post contains links Faro : The pic you include also serves to illustrate the fact that airliners are quite low-density contraptions. Refer to the discussions in this thread: ht
53 Soon7x7 : You got me on the physics however, when a wing weighs in at 50,000lbls each, each JT-9 about 8,000lbs, two probably not generating the required 48,00
54 Oldsmoduck : I feel compelled to comment on this. While facts are the greatest recourse for solving any type of problem, a lot of folks fail to interject a little
55 Jetlagged : I don't have to be a high time Boeing pilot to express an opinion on physics. So the amount of "time I have on Boeings" is irrelevant. Your earlier p
56 Jetlagged : Unlikely combination yes, but it remains a possibility. You are taking the usual conspiracy theory line that because something is unlikely it can't h
57 Soon7x7 : In past threads on this issue I have stood my ground based on facts as I know them. Typically I got lambasted as a conspirator regardless of the fact
58 Oldsmoduck : It's also a fact that eyewitnesses to air accidents frequently "see" things which actually didn't happen. But of course!
59 PhilSquares : Agreed, but you have to have some knowledge of the fuel system. It just doesn't add up.
60 Soon7x7 : 735 of them?...Don't know if your familiar with Long Island. The south shore where this accident occurred is a densely populated area. It is populate
61 SEPilot : I have not said that the official explanation is wrong, I have said I am not convinced (and I gather that PhilSquares is not either, and he is far mo
62 Lowrider : No, but if I pulled the inboard throttles to idle while in a climb and pulled the yoke all the way to the stops, I don't think a 747-100 would coast
63 Oldsmoduck : Amen brotha... i felt horrible after asking this person her opinion... i had previously heard in passing from a co-worker of her previous employment,
64 Soon7x7 : Sheeple...Thnx for the support...it's a jungle out there!
65 Moose135 : They created the cartoon in order to discredit the hundreds of witnesses who saw a streak of light rise up from the ocean prior to the explosion of t
66 Jetlagged : I do have, and ignition of fuel vapour must be considered a possibility, much more likely than an accidental shoot-down.
67 Jetlagged : Never thought I'd see these terms used on A.net Tech Ops. Mostly seen on internet forums as a perjorative description of people who "can't see the tr
68 Jetlagged : But it's energy would take it up a considerable distance. It wouldn't stop dead and not climb at all, which is the conspiracy theory view. Yanking th
69 Jetlagged : I don't see how a 3,200 ft zoom climb (in flames) can possibly be confused with an alleged streak of light coming from sea level. So how can it be us
70 Jetlagged : I have more than a passing knowledge of physics and aerodynamics myself, and I know enough not to talk about impossibility without doing some calcula
71 Lowrider : The stalled condition resulting from a high angle of attack is also a high drag attitude. That drag would tend to dissipate the inertia. It may have
72 Jetlagged : On pure energy transfer terms, ignoring any residual thrust, I calculate a zoom to about 5,800 feet is possible. Any engines still running at climb po
73 Lowrider : Is that vertical feet or linear feet? Also how did you account for the increased drag and any reduction in lift? No, but it gives me an idea of how t
74 Jetlagged : Vertical, calculating a trade from KE to PE. As I said this ignores changes in drag, and lift too, so it's only a calculation to find a rouugh idea o
75 Lowrider : Actually the condtion we practice 2 engine approaches in is not to far from this.
76 SEPilot : In order to have a zoom climb, you must have a vertical force. The force from the explosion COULD NOT have done this, as it would have acted AGAINST
77 PhilSquares : As long as it was beyond the 3NM limit, they can exceed 250 below 10,000. In addition, a normal technique on the classic was to select VS on the auto
78 Joecanuck : Since there is no data on what the configuration of the plane was immediately after the explosion, why is it assumed that the nose immediately departe
79 Jetlagged : Well, I suggest you write to the NTSB and tell them they got their sums wrong. They modelled a number of scenarios according to the report, presumabl
80 Tdscanuck : Why would it be at a high angle of attack? Don't confuse angle of attack with flight path angle. A lightly loaded airplane like TWA800 can pull a fer
81 7673mech : r Thank you and well put.
82 Lowrider : I am making the assumption that the sudden shift in CG may have altered the pitch of the aircraft but not substantially altered the flight path.
83 Tdscanuck : It's not really possible to do that. The second you start to change pitch, the flight path angle is also going to start changing. The rotational iner
84 Lowrider : Would the change in flight path angle keep up with the pitch change? I am not sure that it would. The aircraft would also have considerable inertia a
85 Tdscanuck : It definitely wouldn't. It actually can't...the difference between pitch angle and flight path angle is angle of attack, and it's the angle of attack
86 Rwessel : At high speed, the horizontal stabilizer has drastically more authority than needed, and it's plausible that it would have retained enough authority
87 Post contains links MD-90 : That would be a bit of a budget buster for the show, don't you think? Maybe a two hour special but geez, buying a 741 and then blowing it up midair?
88 Lowrider : This is sort of what I was getting at earlier. If the pitch angle and flightpath angle diverged enough in the moment following the separation of the
89 Faro : I am getting confused with all this theorising. I believe the only way to settle the matter is by taking an old 741 frame and replicating the accident
90 Soon7x7 : They did that and had to add propane to the fuel mix for the test as the fuel refused to explode...
91 Jetlagged : The climb, post explosion, happened after the FDR stopped. It's an estimated trajectory. The figure of 3,200 ft comes from the shoot down theorists.
92 Soon7x7 : No, the 3200 foot climb eminated from the CIA cartoon...then they retracted the altutude findings and modified it 200 feet, I love you guys...It's fa
93 Post contains links Rwessel : Some of the first quarter scale tests were done with a simulated "fuel," consisting of a mixture of hydrogen and propane. The point was to have a con
94 ThirtyEcho : That would violate every fuel management dicta in the book. You might use that tank for engine start and taxi but you would not use it for the critic
95 Tdscanuck : No, it was shown to have zero fuel. That's very different. All airliner tanks, and especially the center, have dead volume. Unless you sump the tank,
96 Soon7x7 : Was told by group of TWA mechanics that N93119 had roughly 50 gallons in the center tank at the time...j
97 Jetlagged : Thanks for that. Journalists and conspiracy theorists latch on to small things like that and use it to discredit the whole process.
98 Jetlagged : Like I said in an earlier post, read the NTSB report and forget about "CIA cartoons" (200 ft would be far too small a figure BTW). It doesn't matter
99 Post contains links JoeCanuck : The NTSB report suggests that from the explosion altitude of 13,800, the plane, (which was in a climb at the time), climbed another 1200 - 2200 ft, no
100 Post contains images Soon7x7 : I related the 3200ft climb to the CIA cartoon. I did not say the NTSB reported this. Before TWA800, the NTSB were Gods of investigations. These guys
101 Tdscanuck : That's normal for accidents with suspected criminal involvement. Same thing happens with any bombing, which is what TWA800 looked like until well int
102 Faro : In other cases of suspected criminal involvement, have the FBI retained recovered materials from the accident site? It would be interesting to know w
103 Soon7x7 : Your half right...The NTSB would 100% of the time kick off their investigations and when foul play was suspected, the NTSB would bring in the FBI. In
104 Jetlagged : Like I said, forget the 3,200 ft. However remember that theoretically a much greater climb was physically possible, so a climb of that magnitude is q
105 Tdscanuck : Yes, but the most obvious example (9/11) just flames up even more conspiracy theory, so I'm not sure we want to go there. When was the last example o
106 Soon7x7 : To be unemotional about such an event having been close to it is unrealistic...To accuse the very TWA employees that worked on the plane and dispatch
107 Jetlagged : You're entitled to yours too. However I didn't accuse ex-TWA employees of anything, I just said the NTSB are likely to know more than they do and hav
108 Soon7x7 : Jetlagged "However I didn't accuse ex-TWA employees of anything" Yes you did, you dispell the words of "ex-TWA empoyees" as rumours, when in fact TWA
109 Jetlagged : They know what they need to know, which is a great deal. People who fix planes can't design them, might not know much about fuel vapour combustibilit
110 Soon7x7 : I had seen video footage of the explosive test and the investigators, scientists, whoever they were were having touble with the experiment as I recal
111 Jetlagged : So the spare engine information is really a red herring. So why mention it? If that's the crucial information from the despatcher that the NTSB missed
112 Soon7x7 : With out a doubt the fuel tanks went, just don't think a simple spark can ignite JetA without atomization of the fuel first. I wouldn't speculate on
113 Tdscanuck : Yep. I think you mean vapourization, not atomization. Atomization is just a way to speed up vapourization. And an A/C pack will get the tank plenty h
114 Faro : If they claim, or a majority or significant proportion of them claim the streak originated from the ground up, it might indeed not be a missile. The
115 Soon7x7 : Quite possibly a meteor with dyslexia?...
116 Tdscanuck : I can't think of any way to explosively break up a fully fueled aircraft apart in midair without causing a streak of light...that's a *lot* of burnin
117 Soon7x7 : I'm probably one of the few surfers thats sits on his board and will let a good wave pass by as I'd prefer to watch the Euro bound 747 pass over head
118 Faro : Very interesting possibility; if someone someday crunches the numbers on such a scenario, it may indeed provide an explanation. However I do recall a
119 Soon7x7 : Your scenario was already exercised by the CIA and FBI upon completing interviews with key eyewitnesses. This had been part of the argument of the wi
120 Jetlagged : Sorry to labour the point, but the NTSB report goes into some depth about how they (the NTSB) attempted to reconcile the streak of light eyewitness r
121 Soon7x7 : If I were a betting man, my $$$ is on the NTSB!...always will be.
122 Jetlagged : I'm glad we're agreed on that. The CIA's and FBI's views on accident investigation can safely be ignored.
123 Soon7x7 : I'll share a pint to that!...j
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