TWA 800 considered analysis(fwd post)
This is a forwarded post from a, unknown to me, web source. A fellow pilot posted it on an inhouse pilot site.
An intriguing, insightful, breakdown of flight TWA 800 accident analysis/report, and a seemingly knowledgeable "answer". TWA800 1996 An analysis by Timo Niroma Item: Aviation Accident: In-Flight Breakup Over the Atlantic Ocean, TWA Flight 800 Boeing 747-131, N93119 near East Moriches, New York, July 17, 1996. The official view The main conclusions of the National Transportation Safety Board (Public Meeting of August 22-23,2000). 5. The in-flight breakup of TWA flight 800 was not initiated by a bomb or a missile strike. 9. The TWA flight 800 in-flight breakup was initiated by a fuel/air explosion in the center wing tank. 11. It is very unlikely that the flammable fuel/air vapor in the center wing tank on TWA flight 800 was ignited by lightning or meteor strike; .... 16. A short circuit producing excess voltage that was transferred to the center wing tank fuel tank quantity indication systemwiring is the most likely source of ignition energy for the TWA flight 800 center wing tank explosion. Probable cause: "The source of ignition energy for the explosion could not be determined with certainty but, of the sources evaluated y the investigation, the most likely was a short circuit..." My personal view I agree that the breakup of the plane was initiated by a fuel/air explosion in the center wing tank. I disagree that the initial event for this explosion was a short circuit excess voltage. My scenario is as follows. One can calculate that on statistical basis a meteorite whose size exceeds 1 cm, will hit an airplane in air once in 30 years at today's density of flying and size of airplanes. Of course this is a figure with great error margin, because many of the parameters are somewhat a guesswork. But at least the figure gives direction. Of course the 30 years has a Poisson distribution. After having done my calculations I just read an article by three American scientists who had made the same kind of calculations concerning different targets: men, cars, houses etc., and airplanes. As to airplanes in flight I was surprised that they had the same figure as I: once in 30 years. This leads me to the case of TWA800. We know that the initiating event was the explosion of the CWT. It was not a bomb. It was not a missile. Mechanical failure? What kind of mechanical failure can cause this kind of total destruction? Whatever the initial event was, the rapidity of the chain of events was something never seen by caused by some short circuit. The whole initial event lasted less than a second, probably less than 100 milliseconds. So the only possibility left is that there happened something that has never before happened to an airplane. First some remarks from NTSB. 1. "At time 0.73 seconds before the end of the recording and again at 0.68 seconds before the end, the normal 400 Hz signal with its associated harmonics changed. This change consists primarily of a lack of the upper harmonics of the 400 Hz. During these two different areas the signal contains only the 400 Hz component, no added harmonics." Interpretation: The meteorite penetrated into the plane 730 ms before the black-out and exited 680 ms before it. This 50 milliseconds (0.05 seconds) thru 20 m (?) makes its average speed as 400 m/sec. However while penetrating the plane the meteorite hit several obstacles destroying them. The price for this was exponentially decelerated speed. One could estimate the penetration speed as about 1 km/sec and the exit speed as about 200 m/sec. 2. "The recording appeared to terminate very abruptly with a very loud sound." Interpretation: The hot supersonic shockwave left behind by the meteorite causes the central wing tank overpressurization and the crack just in front of the wings. This cuts all electronic communication. 3. "Fire damage was found on components in the center wing tank; floor beams and some of the seats above and just aft of the center wing tank; part of the fuselage over the right wing; parts of the right wing including the wing front spar; and parts of the left wing just outboard of the number 1 engine. There was heavy sooting on the aft (broken near the midspar) section of the keel beam." Interpretation: Here we have a list of parts that did NOT get the heavy hit, but were near the route of the meteorite and thus bursted into flames due to the tremendous heat caused by the pressure vawe. The fire began only after the affected parts had followed the path of the meteorite and departed from the rest of the plane during the first few seconds after the initiating event. 4. "The wreckage showed evidence of an over-pressurization (explosion) in the center wing tank. Evidence of a center wing tank explosion occurring early in the accident sequence is supported by the combination of fire/sooting/structural deformation patterns along with location of parts found in the first debris field. These parts included center wing tank pieces, parts mounted underneath the center wing tank, and fuselage parts just forward of the front spar, all found along the first part of the debris path." Interpretation: This shows the path of the meteorite. 5. "Side-of-body ribs that separate the main wing tanks from the center tank are more highly fragmented than the other parts. Pieces of the tank that were found in the first debris field below the flight path of TWA 800 show little if any fire or soot damage. These include the majority of the parts from the front spar and spanwise beam #3, and the manufacturing access panel from spanwise beam #2. No other pieces of spanwise beam #2 were found in the first debris field." Continues the above list. 6. "Most pieces of spanwise beam #2 were extensively fire damaged, with small areas of melted aluminum at various locations. However, the manufacturing access panel (CW703, Tag 490) in spanwise beam #2 was found in the first debris filed and is almost free of any fire damage or sooting. One piece of spanwise beam #2 located to the right of center exhibits extensive compression (accordion) damage from right to left. This compressed section of the spanwise beam is uniformly discolored (heated/sooted) in the folds, and showed no marks or scrapes from impact with another metal object. While this "accordion" piece has fractures in the folds, it is basically intact and is attached to a large piece of the upper skin. It was located in the last debris field." Interpretation: CW703 of beam #2 was hit on its left side. The right side of the beam #2 suffered fragmentation but did not get lose in the first place. 7. "Large pieces of the fuselage immediately forward of the front spar are also free of fire/sooting and were found in the first debris field. Main cabin floor beams and flooring material (composite fiberglass) were also found in the first debris field and are free of fire/soot damage. The two air cycle machines (ACM) located under the forward part of the center wing tank to the right and left of the keel beam were recovered from the first debris field. These ACM's did not show any heat damage, and the turbine sections were intact." Interpretation: Keel beam was hit. 8. "The two most forward large pieces of upper skin of the center wing tank are free of fire damage. The upper surface of these two pieces is clean of sooting. The lower surface is moderately sooted forward of spanwise beam #3 and outboard of RBL 75. These pieces are fractured at approximately spanwise beam #2. The large upper right skin piece is extensively bowed upward to the right of center. The left piece is also deformed. The upper skin pieces on the right side, immediately aft of the forward piece, are heavily sooted including the fracture surfaces. A large piece of the right fuselage with attached upper tank skin and upper surface of the right wing is heavily sooted. The fuselage section of this piece exhibits evidence of melting aluminum and "broomstrawing". (A phenomenon that describes the appearance of metal (aluminum) that is partially melted and then subjected to shock loading that results in a broom-like group of fibers.)" Interpretation: An excellent description of a small and hyperrapid vehicly penetrating the left part of the spanwise beam #2. The environmental damage is just what would be expected. 9. "Small areas of the upper and lower skins of the center wing tank are missing." Interpretation: Enter and exit wounds. 10. "The keel beam was broken between the midspar and spanwise beam number 1. The forward piece is relatively clean with some sooting just forward of the trim air tube that passes through the keel beam at approximately station 1125. The fracture surfaces on this section of the keel beam are free of soot. The aft section of the keel beam is heavily sooted including the fracture surfaces." Interpretation: This is a separation point between what the shock wave took with it and what was left. 11. Passenger cabin seats above the center wing tank include rows 21 through 27. Fire damage: row seats 21 8 9 10 22 8 9 23 8 9 24 4 5 6 25 1 2 3 26 4 5 6 7 27 4 5 6 7 28 4 5 6 7 29 8 9 10 30 2 8 No seats forward the center wing tank (forward of front spar) showed fire damage. No passengers showed inhalation fire damage or serious external burns. Interpretation: The meteorite penetrates into the cabin between rows 25 and 26, on the right side, just above the right wing, proceeds to the left reaching the center at row 23, where it penetrates the floor. 12. "There was no evidence observed of projectile penetration of the aircraft structure below the center wing tank. Evidence of a fuel vapor explosion (overpressurization) in the center wing tank was noted on the front spar, spanwise beam number 3, parts from spanwise beam 2, the bottom and top tank pieces. Based on the fire damage and soot deposits, a fire occurred after the explosion in this tank. An ignition source for this explosion, has not as yet been identified. No evidence of electrical arcing or other mechanical failure has been noted on the hardware." Interpretation: Surely not below, the bottom of the CWT was not on the route of the meteorite. The wounds are on the roof, inside and in the front on right side. 13. "Wreckage item CW504 is a flat irregularly shaped portion of the front spar on the far left side of the center tank. The breakup sequence indicates that CW504 may have left the airplane with significant angular momentum. The departure sequence would result in CW504 rotating counter clockwise when viewed from the top and left of the aircraft." Interpretation: CW504 got a bull eye's hit. 14. "Fracture surfaces of CW504 appear clean. At the upper outboard corner of the aft surface, there is an area of brownish, elastic material in a non-uniform splattered pattern. The area is roughly triangular with a hypotenuse from 30" down on the left edge to LBL83. There are small punctures with edges curled forward near the top at LBL 95 and near LBL 76, 3 feet from the bottom of the piece." Interpretation: Hardly needs any commenting. 15. "There is no sooting on the upper skin of the CWT forward from SWB2. Before that there is sooting mostly on the right side." Interpretation: The boundary between what the meteorite or rather its blast vawe tore apart and what it left. 16. "There is no sooting in spanwise beam #2, forward surface, left from LBL34. Much of the upper left is missing." Interpretation: The upper left was wound off. 17. "Skin puncture at 26, ends at 23." See above. 18. "Center Tank Left Override Jettison Pump. The end cap was broken off and the stator windings were exposed and crushed. The end of the rotor shaft was missing. The outer housing had two holes and the flange was missing. The inlet pipe check valve was in the up position and the inlet pipe was missing. The jettison transfer butterfly valve was partly open. When the case was removed, two pieces of a clear, soft, rubber-like, translucent foreign material was found. They were located on the OD of the motor/impeller housing circumferential groove at the inlet side of the prioming impeller. Infrared examination by NASA determined that the material was a silicone substance. No members of the team had ever seen this type of debris inside a pump." Interpretation: this may be the decisive piece of information. This is the most clear evidence of the damage caused by a meteorite. The debris in the pump seems to be part of the meteorite. Silicon is the most abundant element in a stony meteörite. 19. "Missing part from 55 to 80 RBL CWT just forward from midspar. Most cracks are around it." Interpretation: On route. 20. "The Front Spar web has punctures and small holes at various locations. Most of the FS stiffeners, which are attached to the aft side of the web, had impact damage on the aft flanges. The damage is approximately 11"-14" below the upper shear ties with the flanges generally crushed forward at these locations. The FS fractured at the connection to the upper skin panel and rotated forward into the forward cargo compartment." Interpretation: The route of the meteorite seems clearly described. This is latter part. 21. "Spanwise Beam #3. The area of SWB3 near RBL 95 was laterally crushed and badly mangled, and the stiffeners were bent slightly forward. Spike-toothed fractures were observed at seven locations on SWB3 between RSOB and RBL 83.24. The structure from inboard of RBL 57 to LBL 75.9 separated into three large sections and was found in the Red debris area." Considering the above notes nothing to be added. 22. "Spanwise Beam #2. The right outboard section from RBL 98.5 to the RSOB rib was heavily distorted and bent with multiple folds. The web was fractured just under the upper chord from RBL 57 to the right outboard end. This piece exhibits spanwise compression damage (accordion shape) to the web and attached stiffeners." As above. 23. "Transparent glass fibers at the ends of the fiber clusters could be clearly observed by polarized light microscopy. An EDS analysis of the clear glass fiber shows high concentrations of oxygen, aluminum, silicon and calcium, with trace amounts of sodium, chlorine, titanium and iron present." Perfect fingerprints of a stony meteorite. So as a summary: ================ The initial impact penetrates the outer fuselage, enters the main cabin around row 26, punctures the floor of the cabin at row 23, then the roof of the CWT. Inside the CWT, the meteorite first shatters part of Spanwise Beam #2, then the left part of the Spanwise Beam #3 (the direction is slightly donwards and sligtly to the left (both approximately 15 to 20 degrees)). After having fractured the front spar into cargo room the meteorite lefts the aircraft on left just ahead of the wings. The whole thing lasts about 50 milliseconds. The shockwave with a vacuum trail and overpressurization around smashes the sides of the CWT, which explodes due to the shockwave 680 milliseconds after the meteorite exited. Part of the spanwise beam #2, spanwise beam #3 and front spar were in the first debris area, so they must have been teared off very early, evidently instantaneously. AND BEFORE ANY EXPLOSION. This is the clue to the whole tragedy of TWA800. The initiating event was not fire. It was not "ordinary explosion" because nothing actually exloded. It was a shock wave. Overpressured air is very strong. Especially in a closed place where it first rushes out of the way of a flying object with a speed of kilometers in second and then comes back to fill the vacuum left behind by the flying vehicle. We have seen its power for example in Tunguska, where it knocked down over 2000 km2 of forest as if they were a bunch of matches. That's why it is so hard to understand, for NTSB as well as many others. There was first a wave of air, then there was a shock wave that caused the explosion and only after that fire. Not vice versa, as "common sense" would have it. Final Evidence: One photograph, one description and Earth penetrating a meteor stream The Linda Cabbott photograph, I think is the key evidence that solves at last the problem of what ignited the central wing tank. The photograph taken by this lady in a garden party on the other side of the LOng Island heading towards the TWA800 plane rising. What you see there is a white glowing thing with a trail. What it was, remains a mystery - Says FBI, NTSB says not even that much. I feel it's however no mystery. Being an amateur astronomer I know that this is just what a bolide (a burning meteor) looks like in daylight. We have only a few pictures of daylight bolides because they of course look much dimmer in daylight than in night-time. Besides in night a bolide may be the greatest source of light for a few seconds and thus difficult to escape an observation. There are, however, pictures of daylight bolides. The most famous of them is the Peekskill meteor. Look at the pictures, the similarity is obvious. According to the FBI the photograph was discarded, because it showed the flying object outside the northern part of the Long Island when at the same time TWA800 was at the southern end. I have estimated that the velocity of the bolide was 4 km/sec or about 250 km/min. If the distance of the bolide and the airplane was some 25 km at the moment the photograph was taken, it would take about 6 sec for them to meet each other. The plane did not much move during these 6 seconds but the bolide did almost all the remaining distance. The photograph shows a low inclination and short tail for the bolide. The very low inclination of the bolide is just what is expected from the damage. The short tail also tells that the photograph does not see the bolide sideways but partly approaching. According to my theory the meteorite/bolide hit the plane just above the right wing, penetrated the CWT and came out forward and downward compared with the left wing. I think that the meteor theory is so difficult to grasp because the speed of a relatively small piece of junk, that penetrated the plane had an unimaginable speed of 1 km/sec. Nobody has ever seen what happens in those circumstances, but simulations show that the heat is tremendous and the pressure wave equally unimaginable. The penetration thus causes damage never before seen. Remember the whole initiating event that crashed to thousand pieces especially the front left part of the CWT lasted - if my calculations hold - 50 msec (0.05 sec). There is nothing to compare this with. Last, let's remember what Mr. Meyer, the helicopter pilot said after the accident: 'First there were one or two several explosions near the plane that caused many projectiles to fly thru the sky with tremendous speed. The nearest living people to see this were two helicopter pilots. One of them, Frederick Meyer, has said that some of them headed towards the plane. He says that he can't tell what the objects were. "Right in front of me, slightly to the left of centerline, at a distance that I then estimated as 10 miles and an altitude that I estimated at approximately 10,000 feet, I saw a streak of light." The light, he said, was reddish-orange and "had a trajectory of a shooting star: virtually horizontal, with a gradual descending curve." The streak lasted three to five seconds and disappeared. "About a second, and then further to my left, along the same trajectory as the streak, I see a violent explosion, which resembles a flak explosion, and I've seen those. It's yellowish-orange and red in color and it generates a little black cloud of smoke, and the smoke generally congeals above the explosion and above the light. It is a high-velocity explosion." This indicates that the bolide exploded before one piece of it penetrated the plane. This explains also why the photograph shows a bolide of size of possible 5 to 10 meters, while the penetrating object was possible at most the size of a golf ball. By the way it seems that the Earth was penetrating an area of cosmic debris from 16th July to 21th July in 1996. (The tail of comet Hyakutake?) The brightest bolide seen in 1996 was July 17th at 00.49 UT over Atlantic. One of the brightest bolides was seen on July 21 over Atlantic and on July 19 over Netherlands. Comments about these pages can be sent to email address timo.niroma@k... [img]null[/img] [ 10 August 2001: Message edited by: LAZYB ] [ 10 August 2001: Message edited by: LAZYB ] |
The center section is preserved and available for additional detailed inspection for penetration of a meteorite from above! The reconstructed section will be used by NTSB trainees.
Meanwhile the CWT fuel/air explosion remains the most probable cause. A theory reinforced again earlier this year when the TG B737 empty CWT exploded at the jetway after 40 minutes with CWT fuel pump left running and packs on high with OAT at 93F... Ditto in 1991 with PAL 737. :p |
...and the "foreign" presence of the silicone material? Ditto, the streak of "light", perceived missile, etc,etc? Or do you see this as the second shooter, grassy knoll scenario?
http://www.stopstart.fsnet.co.uk/smi...ggrinshoot.gif [ 10 August 2001: Message edited by: LAZYB ] |
This was a theory put forth by ME on AVSIG in the immediate aftermath of the crash. At the time AVSIG was THE internet website, this place didn't even exist yet.
It was put forth as a joke, as I was fed up with the media coverage at the time! Shortly thereafter informed sources were running with it. PPRUNE TOWERS probably saw my post and might even remember it. We got a very good laugh when it made the NY POST about a week later... Cheers Wino |
I remember it indeed Wino - I was 20 minutes behind TWA and posted a pirep on the weather conditions on the same thread as yours.
I was glued to the side window watching the whole ghastly thing happening in the water but, working the upper frequencies, had no idea exactly what I was looking at until we landed at BGR. It was a Nordstress/ Alitalia 767 crew ahead of us who were closest to the explosion. On a lighter note PPRuNe was well underway at the time - just smaller and, as yet, imperfectly formed ;) [ 11 August 2001: Message edited by: PPRuNe Towers ] |
Hmmm, I don't remember coming into PPRUNE untill early 97. Maybe I got my timing wrong, but I remember it being discussed on AVSIG. It was especially discussed by that idiot that was banned for saying that all pilots were drunks etc...
I do remember that it seamed a lot "Clunkier" at the time probably due to the low bandwith of modems back then. Back to the thread, when the newswires (including one guy we knew was a reporter) started running with my bullshat theory, that was forever the end of me and intelligent journalism. I view most internet conspiracy sites several cuts BELOW that... Cheers Wino |
http://www.stopstart.fsnet.co.uk/smilie/badrazz.gif
Ahh, the wicked web. Does putz have 1 or 2 "u"s? I'll give you this Wino, it seemed so legit. http://www.stopstart.fsnet.co.uk/smilie/rolleyes.gif |
It was a Nordstress/ Alitalia 767 crew ahead of us who were closest to the explosion Rod |
All times are GMT. The time now is 13:38. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.