TWA 800 Cargo door area reconstruction showing rupture at aft midspan latch of forward cargo door inflight and destruction sequence description.
Outward opening skin indicates expansion from within, not outside pressure pushing inward. Red paint smears indicate metal below expanded upward and slammed into skin above transferring paint. (Witnessed on other aircraft who underwent similar event.)
Most of door missing indicates unable to claim it did not malfunction.
Right side of fuselage damage only and port side smooth indicates not center tank explosion which would give equal bilateral damage not the one sided damage shown above. 1 Nov 97
Projected description of destructive sequence when aft midspan latch ruptures in forward cargo door inflight on high time Boeing 747s, based upon NTSB AAR 92/02, NTSB wreckage reconstruction of TWA 800, CASB Aviation Occurrence VT-EFO, Indian Report of Court Investigation "Kanishka", UK AAIB Aviation Accident Report 2/90, FAA ADs, and UK Comet accident reports:
Sequence of Destruction for TWA Flight 800
Aft Midspan Latch Rupture in Forward Cargo Door
Wire bundle gets chafed by continuous door openings and closings on it. Sheath around bundle gets worn through to insulation. Insulation gets worn through to bare wire. Bare wire shorts against metal powering on door motor which turns cam sectors to unlocked position. On TWA 800, at 13700 feet MSL and 300 KCAS, the eight lower cam sectors were prevented from unlocking because of the strengthened locking sectors which now have steel doublers as per AD 88-12-04. However, the two midspan latches have no locking sectors at all. The slack in bellcranks, torque tubes, and high time worn cam latches allowed the aft midspan latch to rotate just past center allowing the 3.5 PSI internal pressure to rupture the forward cargo door at the aft midspan latch.
The nine foot by nine foot squarish door burst open at midspan latch sending the latch and door material spinning away in the setting sun which reflected upon the shiny metal and appeared as streak to ground observers. The aft door frame was clean of attachment to door and bulged outward. The door fractured at midline and shattered. The bottom eight latches held tight to the bottom eight latch pins on sill while bottom external skin of door blew away. The top piece of red door slammed out and up smashing into the white fuselage skin above leaving the red paint on the door on the white paint between passenger windows above. The top piece of the door took the hinge with it and fuselage skin as it is tore away. The hinge appears to be working normally while having overtravel impression marks on the opposite hinge when door overextended to slam on fuselage above.
The now uncompressed air molecules rushed out of the nine foot by thirty foot hole equalizing high pressure inside to low pressure outside. The sudden rushing air was recorded on the Cockpit Voice Recorder as a sudden loud sound. The explosive decompression of the forward cargo hold disrupted the nearby main equipment compartment and abruptly shut off power to the Flight Data Recorder.
The door hole was now at least nine feet by thirty feet large. At least nine passengers were blown out of the hole into the nearby number three engine which mulched them up into tiny bone fragments. The number three engine also ingested metal in baggage and started on fire from inefficient burning of fuel. Then the number three engine with pylon started to vibrate and soon detached from wing as designed.
The floor beams were bent, fractured and broken. The main structural members of door and frame were gone and compromised. The flight attitude of the aircraft was askew to the left from reaction of explosive decompression to the right. Air rushed into the hole and weakened other skin and frame peeling skin outward. The 300 knots of air pressed upon the weakened nose and crumpled it into the large hole. The nose tore off and fell and landed in a dense heap before the rest of the plane.
Pieces of baggage and fuselage skin flew backward and left more severe damage on starboard side, such as right wing fillet, of TWA 800 fuselage than port side.
The port side forward of the wing was smooth and unshattered while the starboard side forward of the wing is shattered, torn, and frayed at ruptured cargo door area.
The rest of the plane without the nose suddenly decelerated from 300 knots and caused whiplash injuries to passengers. Passengers inside fuselage had baro-trauma to eardrums which ruptured trying to equalize middle ear pressure. The plane maneuvered with huge gaping wound in front increasing drag. The wind force disintegrated the fuselage and wings. Fuel poured out of ruptured tanks. The broken fuselage, the ruptured wings, the fuel cloud, the center tank, and the spinning, on fire engine number three met at 7500 feet and exploded into a bright loud fireball putting singe marks on the fuselage skin while leaving the nose burn free. Center tank exploded/caught fire as well as other nearby fuel tanks. The debris falls and spreads out from 7500 feet to sea level.
Ground observers hear the fireball explosion of the center tank and other fuel and look up. Noise of fireball to observers is about 50 seconds for the ten mile distance. They see the still falling shiny pieces of the forward cargo door as it is still falling from 13700 feet to the sea in about 60 seconds.
The detached burnt engine number three and pylon fall apart from the other three engines which fall together.
Explosive decompression at the forward cargo hold led to suspicion of bomb in cargo compartment but bomb later ruled out.
Streak of shiny metal object spinning away reflecting evening sun to ground observers led to suspicion of missile but later ruled out.
Fire/explosion of center tank into fireball leads to suspicion of center tank explosion as initial event but difficulty arises in determining ignition source, fuel volatility, unheard of explosion sound, unilateral damage, and weakness of tank needed for such an initial explosion.
Fuselage rupture at aft midspan latch of forward cargo door inflight is initially rejected because most of latches are found latched around locking pins.
Further investigation reveals door rupture at aft midspan latch in forward cargo door possible with bottom latches latched and midspan latches missing.
Questions about center tank explosion as initial event which
1. Sudden loud sound on Cockpit Voice Recorder is described as start of aircraft breakup but not sound of explosion. How can an explosion in the center tank be powerful enough to start the aircraft breakup and blow off nose of Boeing 747 and not be heard on CVR?
2. Center tank explosion would be spherical, not directed, and would either give no damage forward of the wing or about equal damage on both sides of the fuselage of TWA 800. The wreckage reconstruction shows smooth skin with little damage forward of the wing on the port/left side yet severe, shattered, torn, and frayed damage on the starboard/right side of the fuselage in the cargo door area. How can a center tank explosion cause unilateral damage only on starboard side?
3. TWA 800 wreckage reconstruction shows outward peeled skin, outward rupture hole, and paint transfers. Water impact damage would be inward, not outward. How could water impact damage produce outward peeled skin, outward rupture hole, and paint transfers?
4. TWA 800 wreckage reconstruction shows red paints smears only above the forward cargo door area and nowhere else on both side of the Boeing 747 fuselage. This indicates that the red painted door below ruptured/opened outward, slammed upward, and smashed into the white painted area above and transferred red paint from door onto white paint between windows. How did red paint smears get where they are?
5. A center tank explosion would be far enough away from power cables to allow the Flight Data Recorder to record longer than the abrupt power cut it suffered. How can a center tank explosion which is not loud enough to be heard on the CVR and some distance away be strong enough to abruptly cease power to the FDR?
6. How could forward cargo door rupture/open when bottom eight latches are latched and locked in TWA reconstruction?
7. How could forward cargo door rupture cause center tank explosion?
Answers of forward cargo door rupture to questions which
1. Sudden loud sound is sound of explosive decompression which gives a sudden loud sound when forward cargo door ruptures/opens in flight. The TWA 800 sudden loud sound was linked to PA 103 sudden loud sound on CVR which was linked to AI 182 sudden loud sound on CVR which was linked to DC-10 cargo door explosive decompression on CVR. UAL 811 had a cargo door rupture/open in flight and recorded a sudden loud sound on the CVR. The sound is the sudden rushing of air molecules which were compressed now moving fast outward to equalize with the lower pressure outside air.
2. Explosive decompression and rupture of forward cargo door area when aft midspan latch ruptures would give shattered, torn and frayed, damage to cargo door area while leaving port/left/opposite side smooth and light damage. Cargo door rupture would give the unilateral damage on starboard side as shown by TWA 800 wreckage. UAL 811 also had unilateral cargo door area damage when its door opened in flight.
3. Explosive decompression in nose of TWA 800 would give outward peeled skin in nose, outward rupture hole, and paint transfers as internal high pressure rushes outward to equalize with the low outside pressure.
4. After the rupture at aft midspan latch the door fractured and upper piece of the red painted door was pushed outward, rotated on its hinge, slammed upward and smashed into the white painted fuselage skin above, transferring red paint to the white painted area between the passengers windows, as shown by the TWA 800 reconstruction. UAL 811 also had paint transfer from door to fuselage when its door opened in flight.
5. The explosive decompression in the cargo compartment would severely disrupt the cargo hold floor and the adjacent main equipment compartment in which the FDR and power cables are located. The severe disruption would abruptly cease power to the FDR. UAL 811 also had abrupt power cut when its cargo door opened in flight.
6. The forward cargo door of Boeing 747s is over nine feet by nine feet square. It has a hinge on the top and eight cam latches on the bottom. On each nine foot side is one midspan latch. The bottom eight cam latches go around eight latching pins. Over each cam latch is a locking sector. The two midspan latches have no locking sectors. The forward cargo door could rupture at the midspan latch and the hinge and bottom eight latches could still be attached to fuselage skin. The top of the door with hinge attached would tear off with the fuselage skin and spin away. The bottom eight latches could stay attached to bottom sill and continue down to the sea with the nose. The middle of the large door can still be ruptured/opened while the lower part stays attached to airframe. Doors can open/rupture with most or all latches latched. TWA 800 reconstruction shows aft mid span latch missing which implies it became unlatched. The aft door frame sill is smooth and not attached to door which implies door opened in that area.
7. When cargo door ruptures in flight a huge hole is created in nose which the 300 knot slipstream tears off. The falling, noseless, structurally compromised aircraft disintegrated into wings of rupturing fuel tanks, fuselage pieces including center tank, and spinning hot on fire jet engine. When falling debris reached about 7500 feet, the fodded on fire engine number three ignited the fuel cloud and center fuel tank into a fireball. Center tank fire/explosion occurred but later and lower than forward cargo door rupture initial event.
The New York Times
July 31, 1996, Wednesday, Late Edition - Final
SECTION: Section A; Page 1; Column 6; Metropolitan Desk
LENGTH: 1244 words
HEADLINE: FATE OF FLIGHT 800: THE OVERVIEW; JET'S LANDING GEAR IS SAID TO PROVIDE EVIDENCE OF BOMB
BYLINE: By MATTHEW L. WALD
DATELINE: SMITHTOWN, L.I., July 30
The front landing gear of the Boeing 747 that crashed off the coast here on July 17 shows such heavy damage that some investigators are convinced that it is the strongest evidence yet that the plane was destroyed by a bomb, Federal investigators said tonight.
The investigators believe that the landing gear was blown off the plane by a bomb blast. But several senior law enforcement officials said tonight that the finding still fell short of the definitive evidence that they said they needed before they could declare the crash the result of a criminal act. The landing gear would have been retracted into its housing inside the fuselage long before the plane exploded, and the hydraulic mechanism that retracts it was found to have "serious concussive damage," the result of a violent blow or impact, a Federal investigator said. "By the way it had been smashed, the bomb experts thought it had been very close to the source of the explosion."
The front cargo hold carrying passengers' baggage was just behind the landing gear. The first-class seating area was above. Investigators said this evening that they believe a bomb might have been in a passenger's bag -- or perhaps in a food cart or a bathroom in the cabin above.
For the last several days, law enforcement officials investigating the crash of Trans World Airlines Flight 800 have been saying privately that they believed the plane was destroyed by a bomb, but they have been waiting to find a piece of clear physical evidence to support their theory. The latest discovery caused a stir among the divers, Navy and Coast Guard technicians and Federal agents who recovered the landing gear on Saturday.
Samples of apparent residue found on the landing gear have been sent to the F.B.I. lab in Washington to find if they hold chemical traces of an explosive. Thus far, they have not found such conclusive chemical evidence.
One investigator who viewed the hydraulic unit described the damage as "more like a crack than a tear."
"The vast majority of the wreckage has been these torn, mangled pieces of thin metal, from the fuselage," he added. "This was a huge piece of thick steel, and it had been blasted is the only way to describe it.
"For more than a week," he said, "everyone had been sifting through this wreckage, desperately searching for some sign of the explosion, but not really knowing exactly what we were looking for. Then when you see it, the kind of visible damage that had been done, you just know."
Investigators also said today that a cargo door, presumably the front one, had been found significantly closer to Kennedy International Airport than almost all of the other parts located so far, tending to support the theory that a bomb blew up in the forward cargo hold, blowing off the door.
The plane, bound for Paris with 230 passengers and crew members, was, in essence, decapitated as it was climbing to about 13,700 feet, spreading wreckage over several miles. The main section of the plane, engines apparently still running, flew on and plummeted to about 8,500 feet. There, it exploded in a fireball that was visible for miles........................................
Report: TWA Wreckage Shows Evidence of Bomb July 31, 1996, 6:48 AM EDT
NEW YORK (Reuter) - The front landing gear of the TWA Boeing 747 that crashed July 17 shows damage from a powerful blast inside the plane, the first physical evidence that the plane was brought down by a bomb, The New York Times reported Wednesday.
The landing gear would have been retracted into its housing inside the fuselage long before the plane exploded and the hydraulic mechanism that retracts it was found to have ``serious concussive damage,'' the newspaper quoted a federal investigator as saying.
``By the way it had been smashed, the bomb experts thought it had been very close to the source of the explosion,'' said the investigator, who was not named.
The front cargo hold carrying passengers' baggage was just behind the landing gear. The first-class seating area was above.
Investigators said they believed a bomb might have been in one of the passengers' bags, or maybe in a food cart or a bathroom in the cabin above the landing gear.
However, ABC News said a National Transportation Safety Board official denied the newspaper's report. The plane crashed into the Atlantic Ocean off Long Island and 230 passengers and crew were killed.
For the last week, law enforcement officials investigating the crash of the New York-to-Paris flight have been saying they believed the plane was destroyed by a bomb, but they have been waiting to find a piece of clear physical evidence to support their theory. The landing gear was recovered by divers on Saturday.
Samples of apparent residue found on the landing gear have been sent to a Federal Bureau of Investigation laboratory in Washington to find if they hold chemical traces of an explosive. So far such conclusive physical evidence has not been found.
One investigator who viewed the hydraulic unit described the damage as ``more like a crack than a tear.''
``The vast majority of the wreckage has been these torn, mangled pieces of thin metal, from the fuselage,'' he said. ''This was a huge piece of thick steel and it had been blasted, that is the only way to describe it.''
Investigators also said that a cargo door, presumably the front one, had been found significantly closer to Kennedy International Airport, where the flight originated, than almost all of the other parts located so far.
That find tended to support the theory that a bomb exploded in the forward cargo hold, blowing off the door.
Both ABC and CBS, however, reported that the newspaper's report had been denied by an NTSB official. Assistant FBI Director James Kallstrom, who predicted two days ago that investigators would have more clues by now, said he felt more optimistic after a second heavy duty U.S. Navy salvage ship came on the scene on Tuesday afternoon.
``I suspect when we get more of the plane, we will know the answer,'' Kallstrom said.
Officials have said that giving priority to the recovery of victims' bodies over the recovery of evidence has slowed the investigation somewhat.
But, Robert Francis, vice chairman of the National Transportation Safety Board, said: ``We're going to know why this airplane came down in the water.''
Both Francis and Kallstrom insist they lack the critical evidence needed to decide on any one of their three leading theories -- a bomb, missile or mechanical failure -- or to rule any one out. The Paris-bound plane erupted in a fireball about 70 miles (113 km) east of New York City.
``There are unprecedented things that happen on these complex aircraft that are not foreseeable,'' Francis said. ``We really have got to get the rest of the airplane to answer the question.''
Francis acknowledged that investigators studying the cause of the crash could have weeks or months of work ahead of them.
Investigators were eagerly waiting for the salvage ship, the USS Grapple, to retrieve a large piece of wreckage from the front section of the plane. ``I think we'll find out soon how critical it is,'' Kallstrom said.
Officials believe the front of the Boeing 747 broke off first, and the rest of the plane apparently remained airborne for several seconds before falling into the water.
The location of debris in two distinct areas lends weight to the theory that a bomb exploded in a forward cargo hold.
The Grapple is equipped to lift many thousands of pounds (kg) of material, but Rear Admiral Edward Kristensen cautioned that many other pieces of debris entangled with the plane's front section could complicate the process.
On Tuesday, searchers retrieved part of the plane's galley, a cargo door and a piece of its outer skin. Several seats from its first class and business section were visible on a barge filled with debris that pulled up to shore not far from the site of the crash off East Moriches, New York.
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