View Full Version : TWA 800 considered analysis(fwd post)

11th Aug 2001, 01:37
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

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

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

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

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

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 mete├Ârite.

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

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
[email protected]...


[ 10 August 2001: Message edited by: LAZYB ]

[ 10 August 2001: Message edited by: LAZYB ]

11th Aug 2001, 02:35
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.


11th Aug 2001, 03:32
...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?


[ 10 August 2001: Message edited by: LAZYB ]

11th Aug 2001, 05:00
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...


PPRuNe Towers
11th Aug 2001, 17:26
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 ]

11th Aug 2001, 20:01
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...


12th Aug 2001, 00:55
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

Fright Level
12th Aug 2001, 02:30
It was a Nordstress/ Alitalia 767 crew ahead of us who were closest to the explosion

The guys were in trail on departure from Kennedy and were subsequentally called up on HF by the FBI whilst over the Atlantic requesting their presence at the American Embassy, Rome, the following day. I'll chase up the pilots on that flight and get him to reply here if the subject is being raised again.