2.1) TWA 800
Trans World Airlines, Boeing 747-131, N93119, July 17 1996
NTSB Official Factual Reports Regarding this Accident http://www.itsasafety.org/events/twa800/exhibits_web.htm
2.1.1) I think a missile did it. What questions can I expect to be asked to support my theory?
Contributed by Geoff Cashman
1) What launched the missile?
2) Why did nobody see the launch?
3) Why did less than ten people see the launch platform when hundreds saw streaks in the sky?
4) What type of missile attacked the plane?
5) Why is there no evidence of a missile strike on the airplane?
6) Why, when 98% of the plane was recovered, was no physical debris from missile itself recovered?
7) If this was a planned attack, what was the motive?
8) If it was unplanned, why were a multitude of precautions [...] violated?
2.1.1b) Some Frequently Supplied Answers to the above questions.
Contributed by Craig Shields
[The order of these FSA's does not match the above Q's]
1) For the missile to be seen, it would need to be an SM-2 or larger. Therefore, it wasn't a terrorist.
2) Standards require large launching platforms.
3) Of all the people who saw the streak, none saw the launch. This is strange, given that launch pyrotechnics are much brighter than the engine exhaust. Assuming an over-the-horizon shot means that the missile would be in coast and therefore not visible.
4) 98% of the plane was recovered. How could the NTSB, made up in large part of civilians (some of whom would *love* to prove that it was a missile) hide the shrapnel damage? Please do not use Goddard/Rivero's entry and exit wounds unless you want to discuss the splaying of sheet metal in a semi-monocoque structure with an ex-aerospace engineer. I'll win that debate. Hell, I have pictures of gunshot holes that bend toward* the shooter.
5) Speaking of people, thousands would be involved. This would include the ships crew that would know they fired a missile off Long Island right when a plane was downed. How do you keep them quiet? Add to this the civilians who are involved (contractors, etc.) and the incredible paper trail that follows every missile. A hefty number of sailors who were in the service in 1996 have left it. How do you silence them?
6) Why shoot missiles off of Long Island when proper airspace is available (and no, the warning zone was not hot until after the crash, regardless of what Jim "What, Me Add?" Sanders says)?
2.1.2) Isn't it possible there has been a cover-up?
Contributed by John Mazor
Let's admit that it is possible that the NTSB was bamboozled or subverted by higher feds. Okay, what does that get you? "It's a possibility." You have proven nothing. In that vein, it's possible that aliens have been living among us for millennia, shaping human history and destiny. However, I'm not going to invest much time or energy or emotional capital in possibilities such as "Hitler and Stalin were aliens inserted by Zygorthians to promote human advancement through the advancements in technology that the pressure cooker of war provides. And so were three lead scientists in the Manhattan Project."
It's possible, even plausible. But what are the chances? And the only possible proof of the correctness of one or the other side's arguments would be if the "not possible" event is proven to have occurred. But at that point, it is a matter of evidence, not possibilities and faith.
As in any investigative process, once you complete the compilation of concrete descriptions of evidence and scientific testing, you must proceed to analysis and then to conclusions. These processes are subject to human error; but we hire and enlist vast amounts of technical expertise to do the best job that is humanly possible. TWA 800 is no different in that respect.
And as in any investigative process, there are no absolutes [with respect to] getting it right. How many innocent men have gone to the gallows despite our best efforts to make the legal process fair and accurate? Any accident investigator can show you dozens of crashes where there were loose ends and debatable conclusions. Okay, so what does one do? Reject all the outcomes of these investigations?
No reasonable person familiar with these processes would argue that there is zero probability of a missile. Personally, if you put a Colt .38 in my mouth and said "Gimme a number", my probability call would be 99% mechanical problem, 1% missile or bomb.
At those odds, I'm not going to spend a whole lot of time worrying about a missile. At some point you have to conclude that it's never going to get any clearer than what you have now, and move on. (Unless, of course, you believe as a matter of faith that there was a missile and cover-up.)
If we ever find a smoking gun that proves it was a missile and cover-up, no one would be more angry and embittered and disillusioned than I and the others who have professional and personal interests in this accident. But again, that would elevate the issue to a matter of evidence, not possibilities and faith. In matters of consequence, I prefer to act on the former, not the latter.
2.1.3) What about the eyewitness accounts?
Contibuted by Eugene Griessel
Contributed by Paul J. Adam
Forty witnesses said it came from the sea, ten said it came from land.
146 gave a direction. 77 said it ascended, 11 said it descended, 47 said it both ascended and descended, 9 said it flew level.
Direction of travel... total shotgun approach.
If you average them out... which is akin to saying that immersing one hand in molten lead and the other in liquid nitrogen is, on average, comfortable...
The trouble comes when you try to fit a missile to the statements.
Contributed by Dr. George O. Bizzigotti
Here's an interesting example of why some of us with technical backgrounds are skeptical of some of the eyewitness reports. Lisa Perry was quoted in Dan's Papers, Long Island, 15 May 1998, as follows:
"The plane stopped for an instant, as something would when it had suffered an impact, not just an explosion. Then it began to fracture - as if you had slammed a frozen candy bar down onto a table. You could see the spaces in between the parts of the plane. Then a moment later there was another explosion and the plane broke jaggedly in the sky."
Paul Adam has made this point before, but I would like to go into detail here so that hopefully everyone can appreciate the arguments. I have seen estimates that put Ms. Perry's position 15.7 nautical miles (18 statute miles) from the crash site; that's 95,400 feet horizontally. Because she was on the ground, and TWA 800 was at 13,800 feet, she was 96,400 feet from TWA 800. A Boeing 747 is 232 feet long and 64 feet high, so TWA 800 would have appeared in Ms. Perry's field of view as 8.3 arc-minutes high by 2.3 arc-minutes wide.
Now let us digress into the world of bio optics. Our eyes work because photoreceptor cells on our retinas absorb light. we are only capable of telling whether or not a cell absorbs the light, so each cell corresponds to a pixel in an image. The maximum density of the photoreceptors in the human eye is 160,000 per square millimeter. This translates to a minimum distance between these receptor cells of 2.8 micrometers. One degree of visual angle is equal to 288 micrometers on the retina, so the minimum distance between receptor cells corresponds to 0.6 arc-minutes. Based on this, the image on Ms. Perry's retina likely covered something like 50 cells out of the 100 million receptor cells in her field of vision.
In addition, the angular resolution of one's eyesight is limited by Rayleigh scattering of light. With a 2 mm pupil diameter and 500 nm light (near the center of the visible spectrum and the wavelength that maximally excites the receptor cells), the minimum angular separation required to resolve two points is 1.1 arc minutes. Thus, the physical properties of light dictate that even someone with absolutely perfect eyesight cannot distinguish between objects less than 31 feet apart at 96,400 feet.
By either argument, being able to distinguish the fine detail implied in Ms. Perry's statement is unbelievable. Have someone slam a frozen six inch candy bar on a table 208 feet away from you, and see if you can "see the spaces in between the parts." How can fifty pixels in a 10,000 x 10,000 image be anything more than an indistinct blur, with little recognizable detail? Note that there's nothing ideological in this argument; Bill Clinton has nothing to do with how retinas work or how light is scattered by an aperture. This is simply what a century of science has shown us about how our eyes and the universe work. Although the overall height at the tail of a 747 may be 63 ft 8 in, the narrower portion of the cabin has a width of only 20 ft; even someone with perfect eyesight could barely distinguish the top of the fuselage from the bottom at the 15.7 nm horizontal distance.
As a result of this, assuming good faith on the part of Ms. Perry, we are left with only two possibilities:
(1) Ms. Perry has eyes that are literally superhuman, or
(2) Ms. Perry has a fallible memory.
Believing option (1) requires us that Rayleigh scattering of light be temporarily suspended for the first and only time in the history of scientific record keeping. Believing option (2) requires us to believe nothing more than that Ms. Perry is human; the tendency of humans to interpolate sincerely believed details that did not actually occur into our memories is fairly well established. Thus, I would cast my vote for option (2), that Ms. Perry has unconsciously embellished her story, perhaps adding some speculative details that she heard on the TV news to her accounts given days later. That being not unusual among eyewitnesses, scientists and engineers tend to place somewhat less credence in accounts that, e.g., saw aircraft windows from over 10 miles away, than in the physical data that is available. This is why we have stated that physical data trumps eyewitness accounts.
I also note that the above does not even begin to discuss the temporal dimension. How long will it take aerodynamic forces to rip apart an aircraft flying at 290 knots with fractures between parts big enough to see? My guess is that Ms. Perry's "moment" would have been incredibly short, likely too short for humans to perceive.
In addition, I believe that "The plane stopped for an instant, as something would when it had suffered an impact" is a misperception. In any collision, the total momentum of the involved bodies is conserved. TWA 800's dispatch release indicated that the takeoff mass was 590,441 pounds (http://www.ntsb.gov/events/twa800/exhibits/Ex_2A.pdf); it would have burned off some of that mass during its short flight; I'll estimate 15,000 pounds. The flight data recorder shows a velocity of 290 knots immediately prior to the accident; TWA 800 had a momentum of 575,000 pounds times 489 ft sec-1, or 282,000,000 ft lb sec-1. The Standard SM-2 Extended Range missile, probably the largest missile mentioned as a candidate for the TWA 800 accident, has a mass of 2,980 pounds. Finding unclassified values for missile velocities is difficult; the highest value I have ever seen reported, even for missiles considerably smaller than the Standard is Mach 4, or roughly 2,660 mph. The Standard has a momentum of 2,980 pounds times less than 3,900 ft sec-1, or less than 12,000,000 ft lb sec-1. Even if a Standard hit a 747 head on, it would reduce the 747's momentum by no more than 12,000,000 ft lb sec-1. The 747 with the Standard sticking out the front would have a momentum of 270,000,000 ft lb sec-1; divide that by the combined mass of 578,000 pounds, and one finds that the wounded 747 would be traveling at 277 knots. Note that if the missile struck from the side or the back, the velocity would actually have increased. Also, note that because the explosive warhead is included in the mass of the missile, an explosion, although doing considerable damage, would not significantly affect the momentum of the missile-aircraft combination. We can debate how fast a missile might have been traveling, or how heavy it might have been, but the fact is that no missile much smaller than a Saturn V would have a combination of mass and velocity large enough to significantly slow a 747 in flight, much less "stop it for an instant."
See http://psych-server.iastate.edu/faculty/gwells/encyclopediaapaentry.html as a leading reference to a _large_ body of scientific evidence independent of TWA 800 that indicates that eyewitness testimony is very often mistaken. This reference also indicates that "the overall correlation between confidence and accuracy in eyewitness identifications is a modest one." Plainly stated, that means that the science indicates a witness' sincerity does _not_ matter.
2.1.4) Who is Cmdr. Donaldson? Can his results be taken at face value?
Contributed by Dr. George O. Bizzigotti
Cmdr. William S. Donaldson, USN Retired, often appears as the public Voice of the Associated Retired Aviation Professionals (ARAP); their web site is found at http://www.twa800.com/index.htm. Unfortunately, Cmdr. Donaldson has made a number of gaffes that have left his technical credibility in tatters. Two examples spring to mind:
(1) His publicized stunt of dropping a lighted match into a bucket of kerosene as illustrating that "jet fuel can't explode." His stunt had nothing to do with the contents of the center fuel tank of a 747. Jet fuel has a fundamental property called "flammability limits." In the case of jet fuel, the flammability limits, which can expressed as the temperature at which the saturated vapor can support combustion, depend on the pressure, which is in turn a function of altitude. The NTSB's exhibit no. 20D, "Fire And Explosion Groups Factual Report, Appendix IV," gives a detailed explanation of how the flammability limits for jet fuel were measured. Exhibit 20D concludes that the lower flammability limit is between 90 and 100 degrees F at sea level, decreasing to between 75 and 84 degrees F at 15,000 ft.
If a bucket of jet fuel at sea level is cooler than 90-100 degrees F, it will not support combustion; Donaldson can be heard in his video reporting that the temperature is approximately 60 degrees, comfortably below the lower flammability limit. Thus, it is no surprise that Donaldson can extinguish matches in cool jet fuel. Donaldson did do some experiments where he used a modified pressure cooker on his backyard grill to heat jet fuel to 145 degrees, 170 degrees, 185 degrees, and 210 degrees F at sea level air pressure. It is important to note that there is both a lower flammability limit ("too lean" in the vernacular) and an upper flammability limit ("too rich"). I don't have the sea level upper limit, but I'd guess that Donaldson managed to do this set of experiments above the upper limit at sea level. In any event, flammability is a function of composition, pressure, and temperature. The composition and temperature for any of these mixtures are different from that which occurred in the TWA 800 center wing tank. Flammability limits are different at the pressures associated with sea level and with 13,700 feet altitude.
Maintain jet fuel at a temperature between the lower and upper flammability limits, and it will burn quite rapidly. Thus, had Donaldson heated his bucket of kerosene to the same temperature as the center tank on TWA 800 and done so at a higher altitude than sea level, he would quite likely have obtained a very different result, i.e., a rather spectacular whoosh of fire, quite possibly with himself at its center.
The temperature of the fuel in the TWA 800 CWT was at least 115 degrees F, well above the flammability limit for its altitude of 13,700 feet. Arguing that experiments on a pressure and temperature dependent phenomenon conducted at 60 degrees, 145 degrees, 170 degrees, 185 degrees, and 210 degrees F at sea level is relevant to an event that occurred at ca. 115 degrees F and an altitude of 13,700 feet is both disingenuous and a pretty basic scientific error; Donaldson has not made any statement to indicate he's even aware of the pressure/altitude variable, much less adjusted for it.
NB: To be precise, a jet fuel and air mixture does not detonate. However, it burns rapidly (NTSB data indicates no more than seconds between ignition and the generation of the peak pressure in the center wing tank), and in a confined space, it can generate sufficient pressure (Exhibit 20 D provides a range of estimated overpressures from to 13.5 to 73.5 pounds per square inch) to rupture the tank. This rupture releases sufficient energy quickly enough to be considered an "explosion." Those who insist that jet fuel vapor cannot detonate, while technically correct, miss the point that rapid combustion of a fuel-air mixture is capable of causing enormous damage.
(2) His proposal at one point that the Iranians had launched a Phoenix missile from a boat. The problem with that idea is that the Phoenix is an air to air missile, which has aerodynamics designed to be launched at an air speed of several hundred miles per hour. On a boat, with zero or minimal air speed, it will be unstable. Paul Adam has posted in considerable detail in years past on why this is an entirely incredible scenario, but I think I have the gist of his argument.
One would think that being a retired naval officer with "extensive experience as a Naval crash investigator," Cmdr. Donaldson would have known better than to make either of these elementary errors. Yet he persisted in repeating them even after they were shown to be in considerable error; there was still a video of the "match in jet fuel" experiment on ARAP's web site long after exhibit 20D was published. Donaldson seems to be roughly the equivalent of a retired astronomer coming out and saying that the sun revolves around the earth. He will find that there are a number of people who will agree with him based on their observation that the sun keeps coming up in the east and going down in the west. Some may even applaud him for "challenging the established wisdom." However, were he to attend a meeting of professional astronomers, he would be either ignored or ridiculed because several centuries of more precise observation as well as application of the relevant laws of physics say that he is wrong.
I would finish by noting that Cmdr. Donaldson has been invited to speak at a considerable number of meetings of advocates of the TWA800 missile theory and other conspiracies. I assume he gets paid to come speak to these folks; he therefore has a considerable financial incentive to ignore any scientific debunking of his hypotheses, keeping the conspiracy alive and his lecture fees coming. Why is that Donaldson and Sanders, who get paid to write and speak about TWA800 are accorded heroic status, while certain posters on alt.disasters.aviation, who analyze technical issues gratis in their spare time, are derided as shills?
2.1.5) What was that "red residue?" Should I believe the Sanders sample results?
Contributed by Dr. George O. Bizzigotti
Author James Sanders has made a significant argument based on a red residue found on certain seat cushions in the TWA wreckage. Sanders clandestinely obtained a sample of that residue, and submitted it for elemental analysis. The composition of the residue was reported as follows:
Sanders asserted that this analysis is consistent with solid rocket fuel; his assertion is supported primarily by quotes from an anonymous "retired Hughes Missiles engineer and propellants specialist." However, there is abundant technical literature that indicates that solid rocket fuels fall into two general categories: nitrocellulose-based fuels and composite fuels containing aluminum, ammonium perchlorate, and a polymeric binder, typically butadiene or polysulfide rubber. Sanders arguments concern composite fuels, so I'll concentrate on that. Kirk-Othmer's Encyclopedia of Chemical Technology (4th ed., Vol 10, p. 72) indicates that composite rocket fuel is typically 70 percent ammonium perchlorate, 18 percent aluminum, and 12 percent polymeric binder; if the binder is polybutadiene, one would expect the fuel to have a composition of 18.00% aluminum, 10.66% carbon, 3.74% hydrogen, 21.12% chlorine, 8.35% nitrogen, and 38.13% oxygen. Other compositions are possible, but none come any closer to matching Sanders' result. Sanders results account for 63% of the elemental composition, so any carbon, hydrogen, chlorine, nitrogen, and oxygen can account for no more than 37% of his material versus the 82% expected based on the technical literature's composition. The aluminum value is lower than expected by a factor of six. Clearly, the measured composition does not match (typical criteria are measured = expected plus or minus 0.4%) the expected composition.
I begin as a skeptic because Sanders source is a "retired Hughes Missiles engineer and propellants specialist." Hughes doesn't make rocket motors; they buy them from subcontractors (e.g., Aerojet, Alliant Techsystems, Morton Thiokol) that formulate the propellant. This is roughly equivalent to "a retired Delta Airlines aircraft designer" giving an opinion on the composition of materials in the 777; its not completely ridiculous, but one might be quicker to accept at face value if he or she had worked for Boeing. The anonymous source argues away most of the discrepancies, but on closer inspection, he or she is wrong on several counts. Magnesium (at 18 percent in the sample) has been used experimentally as an igniter or to increase combustion temperatures, but in much smaller proportions. The silicon (at 15 percent) is described as a "possible binder component."
However, no one has ever reported using a silicone rubber binder in a rocket propellant, probably because silicone does not provide sufficient energy when burned (much of the energy in solid rocket propellants come from the organic rubber binder). Sanders also asserts that calcium (at 12 percent) is used as a "heat or shock sensitive explosive." That's a curious assertion; calcium nitrate might be found in small amounts in some explosives, but it is not found in rocket propellant. Rocket propellants are designed specifically not to be sensitive explosives; they burn rather than detonate (implied by the term "sensitive"). The silicon and calcium are telling; they make up 27 percent of the sample by weight, but they are not used in anywhere near those proportions in any rocket propellant reported in the technical literature. Neither Sanders nor any of the proponents of the missile theory have been able to explain convincingly how these high levels of silicon and calcium could be found in rocket propellant.
So what could the residue be? I would note that seafloor sediments in general are high in elements such as magnesium, calcium, silicon, zinc, iron, and aluminum, with smaller amounts of many other metallic elements. The exact values found in a sample are variable, i.e., samples taken from within feet of one another will vary by + or - 25 percent (which is why analyzing a control sample from the crash site would not be terribly useful), but the general pattern has been observed in many different samples (I've personally seen this pattern in hundreds of samples over more than a decade). What I (and others) have pointed out is that the Sanders result matches that general pattern pretty well. The argument actually was never intended to "prove" that the residue is sediment, but it rationalizes how a piece of cloth that sat on the sea floor for several weeks could produce the observed analysis. Nonetheless, the key factor for Sanders' credibility is not whether or not he might have analyzed sediment, it is whether the result is consistent with any known rocket propellant. Sanders and others simply assert that the elements found in the sample are typical of rocket fuel.
Sanders credibility is also affected because he did the wrong test. There are other tests, most notably infrared spectroscopy, that allow the nondestructive, conclusive identification of materials. In contrast, Sanders elected to do a destructive test that can never conclusively prove the identity of the material, i.e., one could prepare a mixture of totally innocuous materials that would have the identical elemental composition. A demonstrably poor choice of analytical procedure and an unsupportable explanation for the amounts of the elements present are what discredit Sanders' lab analysis. That the sample, which sat on the sea floor, matches reasonably well with what one would expect for sediment is suggestive, but it is not necessary to discredit Sanders' argument.
2.1.6) What about the surface vessels on the RADAR tapes?
Contributed by Dr. George O. Bizzigotti
The Flight 800 Independent Researchers Organization (FIRO) argues that there were over 30 ships steaming at high speed in the area of the TWA 800 crash. I did a little bit of work this past weekend, and provide here a few questions concerning that assertion; it will be interesting to see if FIRO addresses these questions at today's news conference.
FIRO have posted a graphic: that shows the purported tracks of 35 surface vessels and aircraft; there's an inset showing another 4 tracks, for a total of 39, all identified as a result of radar data.
FIRO has simply assigned certain tracks as "surface vessels," without explaining some interesting aspects of radar. It appears to be well established (see, for example, "Communications Standard Dictionary, 2nd ed.," M. Weik, Van Nostrand Reinhold Co., New York, 1989) that one can readily calculate a "radio horizon," the distance beyond which radar cannot "see." In these calculations, one uses an effective earth radius, which is defined as the radius of a hypothetical earth for which the distance to the radio horizon, assuming rectilinear propagation, is the same as that for the actual Earth with an assumed uniform vertical gradient of atmospheric refractive index. For the standard atmosphere, the effective Earth radius is 1.33 times that of the actual Earth radius, or 5269.67 statute miles (4/3 x 3,952 miles). One can then calculate the distance to the radio horizon using the formula: (distance to radio horizon) squared = (effective earth radius) squared + (effective earth radius + antenna elevation) squared.
In the case of the ISP data, the antenna elevation is the altitude of Long Island Mac Arthur Airport (ISP), ca. 100 ft MSL, plus the height of the antenna, approximately 30 ft AGL. Setting the total antenna height of 130 feet gives the radar horizon of the antenna, 14.0 nautical miles (nm). Using a similar equation, one can calculate the radar horizon from the top of a ship's mast. adding the two radar horizon values together gives the maximum distance at which the ISP radar can possibly reach the ship.
Let's begin with the largest warships in the world; the US Navy's Nimitz class aircraft carriers have a published keel to mast height of 244 feet, approximately 210 feet of which is above the waterline. Thus, the radio horizon for a carrier is 17.8 nm, and it can be seen by a 110 foot high radar from no more than 31.8 nm away. Any further, and the radio waves cannot reach the ship. By my count, 21 of the objects identified as surface vessels (and one aircraft) on http://flight800.org/shp_ln.gif are further than 31.8 nm from ISP, the longest range at which ISP ought to be able to "see" even an aircraft carrier.
Using readily available photographs, one can estimate that the Navy's Aegis cruisers are approximately 160 feet tall above the waterline. Thus, they have a radio horizon of 15.6 nm, and can be seen by 130 foot high radar from no more than 29.6 nm away. Similarly, one can estimate that the Navy's Arleigh Burke class destroyers and Oliver Hazard Perry class frigates are approximately 140 feet tall above the waterline. These have a radio horizon of 15.6 nm, and can be seen by 130 foot high radar from no more than 28.6 nm away. Three of the ships identified on http://flight800.org/shp_ln.gif are between 29.6 and 31.8 nm from ISP; to be seen on radar, they could only be Nimitz class carriers. Two of the ships identified on http://flight800.org/shp_ln.gif are between 28.6 and 29.6 nm from ISP; to be seen on radar, they could only be Aegis cruisers or Nimitz Class carriers. This leaves 9 of the surface vessel radar tracks that could possibly be any Naval ship as big as or larger than a frigate.
One should also note that these are the theoretical maximum ranges for detection. Three major effects will decrease the "real" radio horizons:
- There are 20 foot sand dunes on Fire Island, which is between 9.5 and 11 nm from ISP in the direction covered by http://flight800.org/shp_ln.gif. The radar's radio horizon is 14 miles, meaning that in some directions the radar waves could be blocked by the dunes. This effectively reduces the antenna height by up to 20 feet, and could reduce the maximum detection distances to 30.7 nm, 28.5 nm, and 27.5 nm.
- Structures can block radar propagation. I've checked maps and seen the area from the air; there is a residential neighborhood along Lincoln, Coates, and Grundy Avenues to the southeast of ISP, so there are plenty of structures and large trees between the radar and the area covered by FIRO's analysis. Moreover, much of this area is slightly higher than the airport; topographical maps indicate that there is a rise east of Grundy Avenue (approximately 1.3 nm SE of the center of ISP) that is 10-15 feet higher than the airport elevation. A row of good-sized houses and large trees along that rise could limit the radio horizon even further. Also, note that structures do not necessarily have to be directly in between the radar and the target to interfere; radar beams often include significant energy in side lobes. All of this is responsible for "ground clutter," which is particularly severe when one is searching for objects at low elevation. I have insufficient data to quantitate how this will effect the range of the ISP radar for detecting ships, but these effects will work to decrease that range.
- The structures at the tops of the ships are comparatively small. On the Aegis class, it's approximately 160 feet above the waterline to the tip of the mast, but about 100 feet to the top of the solid structures; the radar horizon decreases from 28.6 nm to 26.3 nm if only the radar returns off the solid walls are detectable.
It is well-known that temperature inversions and strong humidity gradients can increase the range of radar (a phenomenon called "ducting"), and some correspondents have pointed out that such conditions could allow the detection of ships over the horizon. Another poster has pointed out that Picquenard says in "Radio Wave Propagation" (Wiley, 1974) that ducts are almost permanent over the tropical ocean, and another reference says that they are permanent in the trade wind belt. However, a good deal of the path from ISP to the crash area is over land. One can also calculate radar refractivities from the meteorological data in the NTSB docket; the data are insufficient to show whether or not ducting conditions were present in the immediate aftermath of the crash. Certainly, FIRO provided no argument supporting the ability of the ISP radar to detect ships at such ranges.
In sum, FIRO has not made any case to establish that it is possible for the ISP radar to detect surface vessels at the ranges of most of the FIRO tracks. Certainly, FIRO should have provided some explanation of why conventional radar horizon considerations would not apply in this case. In the absence of such an explanation, I would suggest that FIRO's designation of these 22 tracks as "ships" calls into question their assignment of radar tracks to most of the "other" ships as well.
I would propose an alternative explanation for many of the tracks. According to their figure, most of FIRO's "ship tracks" were moving at speeds between 12 and 22 knots. NTSB Exhibit 22A indicates that the winds aloft on 17 July 1996 ranged from 12 knots at 1,000 feet to 21 knots at 16,000 feet in directions ranging from 270 to 335 degrees (from out of the west to north-northwest). Over 20 of the identified tracks are moving in this general direction at speeds that match the observed wind speed. Sensitive radars can receive strong signals from refractive index inhomogeneities, insects, and large dust particles in an apparently clear atmosphere, as well as from clouds. If present on 17 July 1996, such features would appear to be moving between 12 and 21 knots out of the west to north-northwest at altitudes that could be seen by the ISP radar. Note also that many of FIRO's arrows are less than 1 nm long; if this reflects the length of the "track" this would be more consistent with natural phenomenon (which might persist for a few minutes only) than with a warship (which ought to keep reflecting radar signals as long as it's in view).
FIRO makes a rather bold statement as part of their web site:
"The RADAR data indicates that over 30 surface vessels and cooperating aircraft ignored a tragedy that took the lives of 230 individuals. The FBI has allegedly determined the identity of all but one nearby surface vessel. It is now imperative that an explanation for the inhumane behavior of so many fast, large, surface vessels is explained by the investigating agencies, which allegedly accounted for these vessels, recording appropriate interviews."
I would suggest that it is imperative for FIRO to explain the following:
- how they could use the radar data to identify _at least_ 21 ships beyond distances at which the radar should be capable of illuminating something as large as an aircraft carrier, at least using standard principles of radio wave propagation?
- how they can be certain that the many tracks moving between at the same speed and direction as the wind were not caused by natural atmospheric phenomena such as refractive index inhomogeneities, insects, large dust particles, or clouds.?
Moreover, they probably ought to have provided such explanations _before_ they made allegations of inhumane behavior.
No one disputes that _some_ ships and aircraft were in the vicinity when TWA 800 exploded; the FBI and NTSB have stated that from the very beginning. However, the number of ships actually observed would appear to be insufficient to support conclusions of massive Naval exercises, and FIRO's analysis is insufficient to support any increase in that number. Unfortunately, despite extraordinarily weak evidence, "massive Naval exercise on 17 July 1996" seems to have become an article of faith among certain TWA 800 posters.
Contributed by Phil Miller
I would like to add that the beam of a search RADAR is shaped like a paper fan held vertically. That is, it is narrow horizontally (in azimuth), but wide vertically (in elevation). This gives good resolution of bearing, but no height information. An echo from 10,000 feet and one at 100 feet on the same bearing are essentially identical. For civilian search RADAR, altitude information is gathered by Secondary Surveillance RADAR. This is the small horizontal bar like antenna sitting on top of the main RADAR dish. In simple terms, SSR transmits a signal to the transponder in an aircraft which replies with the code set and altitude (if enabled). In this case, if an object associated with a RADAR return has no transponder there is no altitude information for that blip.
The beam pattern is determined by the dish shape. A round dish will create a pencil beam. Good for tracking a known target, but not much good for searching. A peel shaped dish creates a fan shaped beam. The long sides of the dish focus the beam more than the short sides, so you get a fan shape. Sweep this fan through 360 degrees once every 10 seconds or so and you'll cover a lot of sky. Of course if you turn the dish, and it's mount, through 90 degrees, so that it scans vertically, you can get height information, but at the cost of bearing. Combining two or more dishes, one vertical and one horizontal is another way of getting altitude and bearing from a target.
The above does not apply to phased array antennas. Their beam shape is change electronically.
2.1.7) What about the Kabot photo?
Contributed by John Mazor
An improbable scenario:
1. The photographer points the camera 180 degrees from the TWA 800 event and snaps a picture.
2. The Canon SLR camera experiences a possible but extremely rare malfunction, where the mirror only retracts partly out of the optical axis of the lens.
3. Unlike virtually every SLR shot taken under normal circumstances, the photographer is not looking through the viewfinder but is holding the camera away from her face so that her head is not blocking the viewfinder window.
4. The viewfinder window happens to be pointed *right at* the TWA 800 event. (The field of view looking out through the prism viewfinder is fairly limited.)
5. The shutter is snapped during the event.
6. An image of the event goes through the viewfinder, down and around through the prism, strikes a portion of the stuck mirror mechanism that happens to be reflective and happens to be able to reflect a coherent image back exactly to the film plane.
And added to by Craig Shields
7. Do so 10 minutes *after* the explosion.
Contributed by Paul Gooding
The "mirror malfunction" scenario doesn't seem to fit here. As I said earlier, the thing has to happen during a shutter operation. If the camera is a typical SLR, it has a focal plane shutter which physically covers the film plane all the time, except during a shutter cycle. This means that in order for the immaculate image to get on the film, the user has to be taking a photograph. Now think this through: The TWA event is happening behind the photographer. The eyepiece is aimed at the event. Where is the lens of the camera pointed? Down. You are going to have a photograph of the floor, or ground, with the "immaculate image" superimposed upon it. Rather a stretch of the imagination to concoct a set of circumstances where You are going to get an identifiable image of the TWA event -- even if you aim the camera accordingly, you have to presume that the image formed through the eyepiece is in fact a focused image of the type represented by the immaculate cigar. What you'd most likely get is a blur, a streak, something not identifiable. This is true if for no other reason than the fact that your image is bouncing off the mirror in a way other than the way the mirror was designed to provide. You are not going to get a clear, sharp "picture" of an airplane miles away. You might get a fuzzy ball of light, if the explosion were happening at that instant, but that fuzzy ball of light is not going to be attached to a sharply focussed airplane-shaped object. But even this remote (extremely remote -- a meteor hit is probably more likely) possibility is moot when you consider this fact: The Kabot photo was reportedly taken after the TWA event. This means that the film frame with the immaculate image would have to have been double-exposed. In any modern SLR, you can't accidentally double- expose a frame. Further, the subject Kabot photo shows no evidence of double-exposure. Now we are talking about a miraculous possibility that is right up there with images of the Virgin Mary appearing in hot fudge sundaes.
I think an examination of the camera's operation, correlating this to the photo itself, and the locale and scene where the photo was taken, plus information supplied by the photographer, points to one and only one conclusion: The assertion that this photo shows the TWA event is just bunk, and has always been bunk.
2.1.8) Would you agree that CIA video is not credible and does not exclude a missile strike?
Contributed by Craig Shields
It is credible if you believe their assumptions. However, the CIA is not an agency which models airplane flights. This was a mis-guided attempt to gain some ground and pick up some funding.
The NTSB video, on the other hand, is highly credible.
Contributed by Geoff Cashman
[....] since the CIA video was never intended as evidentiary procedure, the inclusion of it as a means of arguement is flawed. Further discussion of the CIA video is not necessary. If you have questions regarding the CIA video, do a search of Dejanews.
This is a strawman. Knock it down for all your worth. Nobody who has any sense of agreement with the NTSB's findings will care. Its existence is tangential to the case, at best.
2.1.9) Wouldn't a formal hearing of the eyewitness evidence provide closure?
Contributed by Dr. George O. Bizzigotti
It's doubtful that "closure" could have been obtained in this fashion unless the NTSB were to agree that it was a missile that brought the aircraft down. If such a hearing reached any other conclusion, I strongly suspect that the same crowd who are now arguing loudly and at length that the NTSB is ignoring the eyewitnesses would be screaming that the NTSB inquisitors browbeat those poor eyewitnesses into submission.
2.1.10) It was an inert telemetry training IR Standard Missile that was mistakenly fitted with a live motor and fired during a CEC test.
Contributed by Paul J. Adam
The missile is being fired from a Mark 41 Vertical Launch System, correct? It's upright, in a sealed canister.
So, how does the seeker *inside* the closed sealed canister, pointing straight up as well, see anything?
Also, on the mockup of a Standard IIIB that Raytheon had on their stand at DSEi'99, the IR seeker is not in the nose, but halfway down the side in a retractable 'eyeball' that extends after launch. So, not only can the seeker not see out of the canister, not only is it not pointed at the target, but it's got its IR seeker retracted...
.....the CEC test would just be about datalinks. Can you get good enough data over the link for targeting? Do the test, bring it back, analyse the data and find out.
Remember, the missile's shut away in a dark cell so there's no way to "test if it's locking on or not" except to fire it... and apparently this beast wasn't meant to have a motor so it's never leaving its cell so why bother putting a very expensive IR seeker and autopilot into it since it can never use either?
2.1.11) What about a meteor hitting TWA 800?
Contributed by Laurence Doering
According to the American Meteor Society home page (www.amsmeteors.org), there is no major periodic meteor shower in mid-July.
[The previous poster was] probably thinking of the Perseid meteor shower, which peaks in mid-August, and which was associated with TWA 800 because of the several airline crews who saw bright Perseid meteors while in the air near Long Island a month after TWA 800 went down, and who reported them to air traffic control as possible missile sightings.
The "micrometeor" theory is even less plausible than any of the missile theories once you look up a little bit of information about meteors. The basic problem with it is that small meteors slow to a terminal velocity on the order of several hundred MPH high in the atmosphere, so by the time they descend to 13,000 feet or so they're no longer glowing, and have nowhere near enough kinetic energy to destroy a 747. Micrometeors burn up completely long before they reach the lower atmosphere.
Meteors large enough to retain a sizeable fraction of their velocity at low altitude would have turned TWA 800 into a cloud of vaporized aluminum, and their impact with the ground or sea would have been an extremely impressive event that the eyewitnesses (those who survived) would definitely have noticed.
2.1.12) I want to troll the group. What is the process?
Contributed by Paul Gooding
The Ten Phases of a TWA 800 Troll
1. Why do you believe that NTSB's position on the case is solid when (a) you personally haven't seen the evidence, or (b) not all of the wreckage was recovered? I am just trying to get an understanding of the issues ....
2. How can you trust the investigation when the FBI apparently took evidence away from the hangar, and never brought it back? Besides, wasn't the government mean to Sanders?
3. Why are you criticizing everything I say? I am a nice person and have a community service award here on the wall to prove it.
4. I thought this was a discussion group but you guys seem to have your minds made up that the government won't lie to you. Well, that's naive and everybody knows that the government is a bunch of liars.
5. You people are a bunch of government shills.
6. Why should I trust you? You can't answer me without using swear words. Obviously you do not know how to carry on a rational conversation.
7. Maybe a lot of people believe the government, but not me. Maybe the media and the politicians have everybody fooled, but not me. I know the truth and I feel sorry for you, you are so gullible. Being a good citizen means asking tough questions, ya know.
8. Oh yeah? Shut the fuck up, yourself. You ain't no stinking expert. There are at least three people in here who know more about (technical subject here) than you do. SO THERE! AND SO IS YOUR OLD MAN YOU MORON.
9. SO EVERYBODY WHO DISAGREES WITH YOU IS A TROLL? YEAH,RIGHT.
10. Thank you for pointing out that (technical fact here) to me. I am just trying to get an understanding of the issue ....
2.1.13) Why do newcomers raising issues about TWA 800 often get ridiculed?
Contributed by Dr. George O. Bizzigotti
My answer would be that newcomers to a.d.a who have read something on the ARAP or FIRO web sites and then raise the issues often do not realize that these issues have been raised and authoritatively rebutted in this forum, frequently more than once. Although most of us believe that technical issues should be discussed in a scientific way, it often tries the patience of the regulars to have to rebut junk science for the fourth time, etc., etc.