Boeing 747 Reasoning behind cargo door hypothesis

The big picture: From identifying the forest, individual trees make sense. A single tree examined alone does not reveal much. Here are the Boeing 747 trees and the forest they belong to:

TWA 800 was a solo ruptured pressurized hull event.

PA 103 was a solo ruptured pressurized hull event.

AI 182 was a solo ruptured pressurized hull event.

UAL 811 was a solo ruptured pressurized hull event.

There are other high time Boeing 747 ruptured hull crashes but they were not solo and they involved getting hit by lightning or flying into the water, the ground, or another airplane.

The only three that match TWA 800 are the above alone, sudden, and fatal hull ruptures.

My cargo door explanation is based on the central intelligence of the similarities in solo pressurized hull ruptures. They all have common consequences and leave similar evidence. I included for background reference in my research the three DC-10 cargo door events. Also included in research was PA 125, a Boeing 747 leaking pressurized hull event.

The DC-10 hull ruptures occurred in the aft fuselage as shown by the evidence after the crashes.

The four Boeing 747 hull ruptures and the one leaking hull have all been located to a small area on the large 747: Forward of the wing on the right side, exactly where a huge square hole has been cut into the pressurized hull; the outward opening cargo door.

Let's get specific:

UAL 811, NTSB report states location of rupture was forward of the wing on right side.

AI 182, Indian report states location of rupture was forward of the wing on the right side.

PA 103, AAIB report states location of rupture was forward of the wing on left side followed immediately by right side rupture.

TWA 800, early New York Times article stated computer simulation located rupture forward of the wing on the right side.

(Documentation of sources is on web site

Now to the causes of the solo pressurized hull ruptures of the four planes above:

The causes have been stated in reports as:

AI 182 as bomb in forward cargo hold or door.

PA 103 as bomb in forward cargo hold.

UAL 811 as bomb or door.

TWA 800 as bomb in forward cargo hold, missile striking forward of the wing on right side, fuel tank explosion severing nose forward of wing, or door.

If TWA 800 had been shown to be bomb then all would be right in the aircraft investigation world. Four catastrophic solo ruptures of 747s; three bombs and one door.

But TWA 800 has been shown not to be a bomb and all is not right in the aircraft investigation world. It doesn't make sense. Something's wrong. If 800 not a bomb, then maybe 103 and 183 not bombs? If not bomb, what?

Let's back up to big picture. The large forest of wide body solo hull ruptures includes three DC-10s and four Boeing 747s. The three DC-10s are definitely in the forest, but are the four Boeing 747s? What else is there to link them to include them as hull ruptures?

If the four Boeing 747 hull ruptures over eleven years can be shown to be extremely similar then they can be assumed to have one common cause. What is it?

I contend they are so similar that they have one common cause. The common cause is a hull rupture forward of the wing on the right side. Were there hull ruptures on the four planes and did they cause the accident? I say yes.

What caused the hull rupture at that location?

Well, every inch of that area must be examined closely. It is already a dangerous area. Section 41 retrofit was done to correct cracks near the rupture area. Several ADs were issued to correct faults in a door which may lead or did lead to a rupture in that area. The pear design at rupture location is not as strong as a circle or oval found aft, near identical door which has not failed in flight. Historically, hull ruptures have been near squarish corners of holes cut in the pressurized hull; there are squarish corners of a big hole in the rupture area.

Regarding TWA 800, I am assuming the fireball and center tank explosion occurred after hull rupture, not before, based on eyewitness accounts of streak and altitude of fireball lower than that at rupture event. Radar data also supports hull rupture first, then, later and lower, center tank explosion. There was a hull rupture forward of the wing, severing the nose, the time and cause is unknown as this time. If the cause of the hull rupture for TWA 800, the streak, and the radar blip anomaly could all be explained by center tank explosion, and if the ignition source were known, then center tank explosion would be conclusive. But the center tank explosion does not explain most of the main evidence for the initial event.

NTSB has been right all along to say mechanical and center tank explosion. NTSB is still right and will be right, it was mechanical and there was a center tank explosion. There is no incompatibility.

Let's assume fireball occurred later and lower than initial hull rupture. Does the hull rupture by a door opening fit the evidence?

A hull rupture would cause an explosive decompression which means a sudden loud sound.

1. There was a sudden loud sound on the four 747s CVRs.

A hull rupture would cause a large hole to open up forward of the wing on the right side.

2. There was a large hole on the right side, forward of the wing on the four 747s caused by the door hole and torn away associated fuselage skin.

At that rupture spot, a weakened nose could be torn off by the tremendous 300 knot slipstream and start a sequence after sudden loud decompression sound:

3. Power abruptly cut at main equipment compartment. All four had abrupt power cut.

4. Passengers sucked out of large hole and ingested into number three engine. All four had at least nine missing, never recovered bodies.

5. Nose falls in dense area on surface. Nose fell in dense area on three planes, on other plane the nose stayed on.

6. Rest of plane disintegrates as it falls leaving wider spread debris pattern. Three had wide debris pattern for noseless planes, other plane kept nose on.

7. Engine number three FODs, catches fire and falls away to land alone. Three number three engines fell away to land separately, two were on fire. Number three engine FODDED on other plane but engine stayed on wing.

8. Inflight damage by debris more severe on right side. Three planes had more severe right side damage and maybe the fourth too.

9. All four planes had ground radar information at time of rupture. Three had nearby lone primary radar blip, the other might have had but was out of primary radar range.

Discussion: The abrupt power cut would prevent most information about the cause of the rupture from reaching alert lights, the FDR, ground control, or the crew. The streak of 800 was only because the light was such to reflect off the fuselage to ground observers. The other hull ruptures all occurred out of sight of land or at pitch dark.

(There are other similarities of the four not immediately connected to hull rupture: all were high time and took off at night, running behind schedule and with EPR gripes.)

I believe that that is enough significant similarities to state that the four high time Boeing 747 accidents were caused by hull rupture forward of the wing on right side.

What causes pressurized hulls to rupture? Lots of reasons. Overpressure caused by bomb or malfunctioning airconditioning, structural defects, design errors, pressure miscalculations, missile penetration, midair collision, faulty windows or doors, and metal fatigue. The evidence must match the exact explanation to be satisfactory.

Submarines and planes are similar in that pressure is a huge consideration and often underestimated. Subs sink when valves are installed backwards. Planes crash when windows pop.

Ruptured hulls have been around as long as they have been pressurized. The Comet lesson was not learned by the 747. The DC-10 lesson was not learned by the 747. Do not cut outward opening large square holes in pressurized hulls. If they are cut then the incredible pressure will eventually force it open or the continued use will weaken the structure to failure.

To say a solo hull rupture is caused by large door opening inadvertently or metal fatigue is just to refer to precedent. It's happened before. It's a normal working hypothesis.

To say hull rupture was caused by center tank explosion by unknown ignition source is to be speculative.

A 747 has never had a center tank explosion of unknown origin in good weather. A 747 has had a hull rupture forward of the wing on the right side by an inadvertently opened cargo door. There have been three other very similar accidents and none was a center tank explosion. They all could be structural failure at the rupture zone.

If a worthy line of investigation into the hull rupture of TWA 800 is a center tank explosion, or a bomb, or a missile, then it is certainly a worthy line of investigation to rule in or rule out inadvertent door opening, or metal fatigue, or structural failure at rupture location, forward of wing on right side.

To rule in or rule out rupture cause requires close examination of fuselage metal at corners of door to see if it matches the metal failure pattern of the corners of the squarish windows of the Comet. It requires close examination of the door latching mechanism to confirm the cam latches were latched around the locking pins. It requires examination of stringers, bulkheads, floor beams, skin, and panels for any preexisting failures. It requires close examination around lone mid span latch of door for failure. It requires examination of door seals for leaking and door frame for previous damage or out of rig condition.

Regarding the complex latching system of the forward cargo door: The problem is subtle. It is possible to say that the locking sectors of the door were in the locked position and yet, the door to be unlatched. The cam sectors around pins is the key item. Was the bottom of the 800 door sill attached to the door latches? Was the door found broken in pieces but unattached to any fuselage? Did the door break at the mid span point? Did the hinge at top of door tear away at corners? Were the locking sectors steel or aluminum?

The rupture evidence of the other crashes now becomes a help. The evidence at the rupture location of 800 can be compared with the evidence of 182, 103, and 811. For instance, the tearing pattern of the rupture location on right side of fuselage for 811 and 103 match almost perfectly, it may match 800 too.

The latch status of FCD of 182 and 103 were unreported, it needs to be determined.

Regarding TWA 800 specifically before fireball: All revealed evidence is consistent with hull rupture forward of wing caused by door failure:

1. Streak is shiny door departing in evening sun.

2. Radar blip is metal door reflecting primary radar energy.

3. Sudden loud sound is sudden loud decompression after door goes.

4. Engine number three would ignite disintegrating wing and fuselage into fireball.

After fireball, evidence is consistent with center tank explosion.

Soon to be revealed public docket should be very interesting to contemplate:

1. Engine breakdown report. (FOD on three?)

2. Item wreckage plot. (Door found where?)

3. CVR data. (Frequency match 103?)

4. FDR data. (Any EPR problems?)

5. Radar plots. (Blip close enough to be door?)

6. Photographs of reconstructed fuselage. (Pattern match 103?)

7. Crew conversation. (The last words of the 800 pilot were to initiate a pressure changing event just before his pressurized hull ruptured, "Climb.")

To summarize: A worthy line of investigation into the crash of TWA 800 is the examination of the rupture area forward of the wing on the right side; specifically the forward cargo door area, to rule out failure of door latching mechanism, or door frame at corners, or blow out at mid span, or other structural failure in fuselage. This recommendation is based upon striking similarities to three other solo ruptured fuselage accidents, none of which was a center tank explosion.

Sudden catastrophic airplane crash: New boss same as the old boss: pressurized hull rupture.

The first anniversary of the crash of TWA 800 is less than two months away. Many will be looking at the spot in the sky in which the 747 destructed. I suggest a recreation to test a hypothesis that a piece of the plane came off and reflected evening sunlight as it spun away appearing as a streak to ground observers and to also confirm the metal piece could be picked up on primary ATC radar.

The security agents are very good at recreating what they believe happened, bombs and missiles. Planes are being blown up and missiles fired at other planes. Let the mechanical proponents have an exercise in recreation.

Based upon the TWA 800 streak and mysterious blip at the same time, both could be related. What hypothesis could explain both? Cargo door could. It would be cheap, safe, and easy to test that idea. In the evenings before the anniversary, observations could be made of regular 747s taking off from Kennedy and passing the event spot at 13700 feet at 300 IAS. The large, short duration, sun reflective flash can be observed off the 747's forward fuselage, moving to engines, aft fuselage, vertical stabilizer, and winglets if 747-400. I have observed this flash many time from my vantage point living under a heavily traveled airway from SF to LA.

On the anniversary evening a C-130 carrying spare old 747 cargo doors or metal object of same size and shapes could fly at 13700 feet as fast as it could go, about 220 IAS, and at 8:31 PM on 17 July, lower the C-130 inward opening aft door and the crew could push out the eight foot by nine foot pieces of shiny radar and sun reflective metal. ATC radar and ground observers could watch to see the track of the object as it slows down horizontally land speeds up vertically in a parabolic curve to the ocean surface. Radar tapes could then be analyzed to see if the object matches the blips before TWA 800 disappearance off scope. Ground observers can be queried to see if observed streak matches the TWA 800 streak. Several passes could be made in the sun reflective window between 8:20 to 8:50 PM.

A mechanical hypothesis would have been tested in a non destructive, safe, cheap, repeatable manner, inadvertent fuselage rupture forward of the wing on the right side. When the streak and radar blip are recreated at the same time and place as TWA 800, a strong case can be made that some part of the airframe flew off just before destruction and two mysteries solved.

Comment: Big picture shows pressurized fuselage rupture near cargo door; small picture shows bomb or missile or center tank explosion near cargo door. Hypothesis has always been fuselage ruptured when cargo door opened; the reason cargo door opened is unknown: could be unlatching, or frame break, or fuselage crack or many other reasons.

Boeing 747-131
Trans World Airlines Flight 800
Boeing 747-237B
Air India Flight 182
Boeing 747-121A
Pan Am Flight 103
Boeing 747-122
United Airlines Flight 811
The Type Airplane
The Damage Starts
The Radar Blips
The Sudden Loud Sounds
The Abrupt Power Cuts
The Fodded Engines
The Inflight Damage
The Missing Bodies
The Torn Off Noses
The Wreckage Plots
More Similarities
The Red Herring: Bomb!
Inadvertent Opening of the Forward Cargo Door in Flight
Forward Cargo Door Section
Introduction Photograph
Introduction Page
Big picture
More pictures.
(larger picture with DC-10 door also)
Boeing 747.html
747cargo door and nose
Airworthiness Directive 79-17-02.html
Airworthiness Directive 88-12-04
Airworthiness Directive 90-09-06
Boeing 747 nose picts right side cargo door
More pictures of UAL 811 cargo door hole
811page68uncommdoranly2.html 800streakexplained.html



800publicappeal.html .