Aug 27 2012

Looking Back at TWA Flight 800

On July 17, 1996 TWA flight 800 took off from JFK airport on its way to Paris. Fifteen minutes into its flight, shortly after climbing to about 13,000 feet, the jet exploded in mid air. The nose of the jet fell off into the Atlantic while the rest continued to fly, erratically while on fire and spewing smoke, until 42 seconds later when there was a second explosion. The right wing and the rest of the fuselage separated and descended as two separate streams of burning debris until they hit the surface of the water 7 seconds later. All 230 people aboard lost their lives.

Sixteen years later there are still those who believe that TWA flight 800 was shot down by a missile. This is despite the fact that the largest and most expensive investigation in history into the crash of a commercial airliner came to a very different conclusion. I had the opportunity this past week to speak to six different eyewitnesses of this tragedy, some of whom firmly believe a missile took down the jet, while others are unsure. The incident remains a classic historical case demonstrating the fallibility of perception and eyewitness accounts.

The Official Version of Events

The NTSB, FBI, FAA, CIA, and even NASA were involved in the investigation of the explosion of flight 800. At first everyone assumed it was a bomb. Jets don’t just spontaneously explode in mid-air. Then eyewitness accounts of a missile strike starting coming in and that became a viable theory (and that is also when the CIA became involved). The FBI interviewed 270 different eyewitnesses, mostly people on Long Island, who had an excellent view of the entire episode from the beach or further inland. There were also eyewitnesses on boats, surfing, and even aboard other airplanes.

The CIA did an extensive analysis of this eyewitness evidence, together with the physical evidence (such as the location of the debris field) and radar evidence and put together a reconstruction of what happened. The scenario I described above is what they concluded – the jet exploded, flew erratically for 42 seconds, then exploded again losing the right wing, with the two sections falling for 7 more seconds until they hit the water. The total time of the incident from first explosion was therefore 49 seconds. In the graphic above, taken from the CIA report, the white dots represent the location of the eyewitnesses.

The NTSB managed to recover over 95% of the plane (and all of the bodies) – a herculean task. From the physical evidence it was clear that no missile struck flight 800. There was no impact zone, no pitting in the metal, no petaling like would be caused in a high-energy explosion. The NTSB ultimately concluded that the center wing tank (CWT) exploded due to mechanical failure. The tank was only 5% full at the time, which means the rest of the tank was full of fuel vapor. The plane had been sitting at JFK during the day with the air conditioners running – they sit right behind the CWT and would have heated up the tank. The climb to 13,000 feet would have caused more fuel vapor due to the lower pressure.

The NTSB concluded that the most likely scenario was that a spark in the fuel gauge of the CWT ignited the heated vapor in the tank. It was the perfect storm of conditions leading to the initial explosion. The jet, a Boeing 747 model 131, was 27 years old.

What the Eyewitnesses Saw

With the official reconstruction of events in mind, it is very interesting to read or hear eyewitness accounts of what they saw. The CIA commented on the fact that eyewitness accounts were remarkably consistent in certain details, and I found this also in the few witnesses I spoke to. Many witnesses had their attention drawn to the event by the sound of the initial explosion. Others were looking south over the water (a common event near sunset on the shore) and noticed the stream of smoke and fire.

Most witnesses at first assumed they were looking at a firework or a flare. This culminated in an explosion, with two streams of burning debris falling to the horizon. Thirty-eight of the eyewitnesses specifically reported that they saw this flare rise up vertically from the ocean, while many others report that it was traveling horizontally (they are divided as to which direction it was traveling).

In addition some (but not all – depending on their location) of the witnesses also heard one or both explosions. One witness I spoke to also heard a “zipping” sound right before the explosion, while another described it as a “pffft” sound. The timing of the audible explosions turns out to be a critical bit of evidence (often dismissed by conspiracy theorists). Flight 800 was 9 miles south of Long Island and almost 3 miles up when it exploded. The CIA calculated how long it would have taken for the sound of the explosion to reach the nearest witnesses on land – and that time is 42 seconds. Most witnesses were farther away and would have heard the explosion 50 seconds or longer after it occurred.

And yet, the witnesses who heard the sound report that it occurred either simultaneously with or shortly after the explosion that they saw. This made perfect sense to them at the time. Their brains constructed the incoming sensory information as a rocket ascending into the sky and culminating in an explosion that they both saw and heard.

It is notoriously difficult to judge distance, velocity, size, and also angles of objects and movement in the sky. There are no depth cues – the brain has insufficient evidence to accurately reconstruct what it is seeing, so it does the best it can, making likely assumptions. Unfortunately, we did not evolve with jets flying overhead. We evolved largely concerned with the narrow plain of our horizontal world, where there are usually foreground objects that help us judge relative distance, and we know the size of objects are can therefore judge their distance. This system fails when viewing objects against the sky.

One witness I spoke to had assumed the crash occurred on land, close to where he was. He had no idea he was viewing something happening a dozen miles away.

The laws of physics, however, are remarkably reliable. Witnesses saw a glowing trail of smoke. Many of them report that the trail zig-zagged, then exploded. Of the witnesses I spoke to, they also heard the explosion between 2 and 12 seconds later. Their 16 year-old memories may be a bit off, but this accords with their testimonies given right after the event. Their judgment of time may also be off, but I doubt they confused 50 seconds with 2 seconds.

It is clear, in my opinion, that the witnesses heard the first explosion shortly after they saw the second. The timing works out perfectly. The “flare” (that some people believe was a missile) was therefore flight 800 itself, after the first explosion, while it was flying erratically on fire and spewing smoke.

Some have therefore speculated that the sound they were hearing was the launch of the missile. It is impossible, however, that so many eyewitnesses covering a large distance would have all heard this launch. Some eyewitnesses felt the concussion of the explosion – a rocket launch would not have caused this to witnesses miles away. There are also no shoulder mounted surface to air missiles with the range to reach flight 800 from the shore. A missile launched from the water would have been farther away than the jet itself.

No eyewitness reports seeing a missile hit an intact jet, and then 42 or more seconds later hearing the first explosion.

The fact that 38 of the witnesses saw the “flare” climb vertically was confusing, even to the investigators. This led the CIA to assume that the jet itself flew vertically for a time after it exploded, but this is very unlikely, and that reconstruction was widely criticized as implausible. They later revised their reconstruction to take this criticism into account, give the jet a much gentler angle of ascent after the explosion.

I don’t think the jet had to climb at all to explain why some of the witnesses interpreted what they saw as something climbing vertically. Remember the mystery missile that hundreds of eyewitnesses saw on the West Coast in November of 2010? It turned out to be only the contrail of a jet (the specific jet is a matter of debate, but it seems likely is was UPS902 from Honolulu flying through southern California). The nearly vertical path of the jet was nothing but an optical illusion.

Conclusion

Many people, including some of the witnesses I spoke to, are convinced to this day that a missile struck TWA flight 800. It is clear, however, that no one saw a missile strike that jet. The physics of the situation makes that impossible to square with what the witnesses saw and heard. There are witnesses who saw a rocket (or something like a rocket) climb vertically then explode, with the sound of the explosion coming at or within seconds of the explosion, and the two trails of debris falling to the horizon about 7 seconds later.

They could not have been viewing and hearing a missile strike an intact flight 800. The timing does not work, but it does fit with them viewing the second explosion at about the time they heard the first, and this also fits the subsequent two streams of debris taking about 7 seconds to fall into the Atlantic. The zig-zagging also fits better with a jet that has already exploded and lost its cockpit rather than a surface to air missile.

We therefore know with a high degree of confidence that people can believe they saw a missile when they didn’t. This fits with everything we know about the nature of optical illusions and the difficulties in constructing visual information against the sky. We also have other events, like the LAX “missile,” that demonstrate this optical illusion effect.

Yet some people are left with the unshakable belief that they saw a missile. They “know what they saw” and the word of the government is not enough to shake their confidence in their own senses and memory.

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21 responses so far

21 Responses to “Looking Back at TWA Flight 800”

  1. MWSlettenon 27 Aug 2012 at 9:16 am

    Excellent exercise in skepticism. A couple of nits:

    Investigators looking for evidence of a missile attack look for “petaling,” like the petals of a flower, not “pedaling,” like a bicyclist. Damn you auto correct!

    The suspect fuel tank is the center wing tank, not the central wing tank. The spark that caused the explosion likely came not from the fuel quantity gauge, which resides in the cockpit instrument panel, but from the sensor or probe in the tank which sends quantity data to the fuel gauge.

  2. Chewon 27 Aug 2012 at 9:37 am

    “Of the witnesses I spoke two” should be “Of the witnesses I spoke to”.
    gentler, not jentler
    The LA mystery missile was coming from Hawaii and heading to Arizona iirc. It did not originate from LAX. The optical illusion of a “missile” climbing vertically only works when the aircraft is flying towards you. If it were flying away from you then it would look like a missile diving vertically. Something else accounted for the illusion of a climbing missile. I’ve always assumed unburned fuel ignited and traveled upward and that mimicked the appearance of the exhaust tail of a missile but I have no evidence to support that idea.

  3. Steven Novellaon 27 Aug 2012 at 10:09 am

    Thanks for the nits. Corrections made. The mystery missile flight – latest info I could find favors UPS902, also from Honolulu.

    Some of the viewers, those East of the flight 800, would have viewed the plane with it flying mostly towards them. (look at the map above)

    But I agree that other factors may have caused this in some eyewitnesses, like falling or trailing debris.

  4. SARAon 27 Aug 2012 at 1:26 pm

    There is nothing so convincing as experiencing something – hearing, seeing, whatever. It’s the same issue with people who see ghosts. You have to have an understanding of the many perception problems in our brain to be willing to overcome something you experience.

    A whole class should be taught on it in high school.

  5. elmer mccurdyon 27 Aug 2012 at 2:38 pm

    I know there have been discussions of this here before, since it’s favorite topic here, but this example – a single, brief, experience – seems the type we’re most likely to remember wrong.

  6. tmac57on 27 Aug 2012 at 7:31 pm

    @ Elmer- This is also a favorite topic of mine. A recent episode of Science Friday featured David Eagleman a neuroscientist at Baylor College of Medicine,where he recounts an experiment where they showed subjects a photoshopped picture of them in a hot air balloon when they were young (even though they had never been in one),and then quizzed them later about the experience,and a significant number recalled vivid accounts of the fictitious incident,despite the fact that it never occurred…At least that’s the way I remember the story on the show…:)

  7. elmer mccurdyon 27 Aug 2012 at 9:35 pm

    Yes, it also seems that long past experiences, especially early childhood, are particularly susceptible. I’m pretty sure that some types of memory are less so than others, and I’ve got some feelings about what they’d be. Any overviews someone could point me to?

  8. elmer mccurdyon 27 Aug 2012 at 9:38 pm

    My feeling being: experiences that are repeated over a long period, especially recently, would be less susceptible.

  9. ccbowerson 28 Aug 2012 at 2:48 pm

    “I know there have been discussions of this here before, since it’s favorite topic here, but this example – a single, brief, experience – seems the type we’re most likely to remember wrong.”

    I’m not sure that single/brief experiences are more likely to be remembered wrong, as much as people will be more convinced that they are remembering them correctly when they are not. Its hard to convince people that their vivid memories may be inaccurate (or even suggest the possibility) … most people are quite attached to the idea that their memories are accurate.

  10. ccbowerson 28 Aug 2012 at 3:37 pm

    tmac57-

    Related to that is the study from last year in which people who watched high imagery popcorn commercials were (1 week later) just as likely to say they have eaten the popcorn as those who actually ate the popcorn. Text only ads did not have this effect.

  11. Bronze Dogon 28 Aug 2012 at 3:45 pm

    Glad I read this. Hadn’t made the connection in my mind about the delay between seeing a distant explosion and hearing it. If I went to see the July 4th fireworks this year, it might have occurred to me. One thing that doesn’t help is Hollywood. In movies, explosions are always seen and heard at the same time, so that’s how we’re made to think of them.

  12. BillyJoe7on 28 Aug 2012 at 5:22 pm

    I’m not sure that Hollywood is to blame. There is always a disconnect when you see something happening in the distance (like someone chopping wood) and hear the sound with a slight delay. It always seems wrong and you have to remind yourself that sound travels slower than light.

  13. tmac57on 28 Aug 2012 at 7:38 pm

    Bronze Dog makes an interesting point that I hadn’t really thought about concerning the way movies (and TV for that matter) usually don’t accurately portray the sound delay between distant,noisy,events,and the sound delay.For the average person who rarely witnesses an airplane or Death Star blowing up in person,there likely is a ‘cinematic bias’®, that may affect not only the way we perceive an unexpected and rare event,but also the way we reconstruct such and event when recalling it for authorities.

  14. DLCon 29 Aug 2012 at 2:26 am

    That’s the problem. no shoulder fired missile could have reached the aircraft (the best of them have about 3 mile range, with a 3 lb warhead meant to take down helicopters. ) and a large ship-fired or surface unit (truck mounted) missile would have been very noticeable for miles around.
    Must have been Zeus’ slingshot.

  15. tmac57on 29 Aug 2012 at 7:55 am

    Note to self: Proofread twice,submit once :)

  16. Bronze Dogon 29 Aug 2012 at 2:05 pm

    I do think Hollywood and the rest of the entertainment media have some part in shaping our expectations about uncommon and dangerous events, which can alter our perception when they do happen. Of course, we do have various instinctive intuitions pointed out, but I think the entertainment business has a habit of catering to them for the sake of sensation at the cost of realism.

    I did originally have one part I was going to put in about conspiracy theorists and how to me it seems they’re also heavily influenced by entertainment: Disasters don’t happen by accident because there’s always some villain who planned it. A character is “genre savvy” if he recognizes that within the movie and appears clever when his prediction comes true. It seems to me that a lot of conspiracy theorists try to be genre savvy about real life, where movie logic doesn’t apply.

  17. tmac57on 29 Aug 2012 at 6:15 pm

    Bronze Dog-Those are some plausible ideas. It might make a worthwhile line of research,if someone hasn’t already looked into it. Who knows how often we are tripped up in our dealings with reality when we are basing our actions on what a Bruce Willis or Lisbeth Salander would do any any given situation beyond our normal experience?

  18. Heptronon 31 Aug 2012 at 8:53 am

    To reinforce the most recent post of Bronze Dog, this is something I found on YouTube regarding the Pepcon chemical plant explosion from years back. Below are 2 links.

    http://www.youtube.com/watch?v=HJVOUgCm5Jk

    http://www.youtube.com/watch?v=_KuGizBjDXo

    The first link shows the video of the explosion which seems more raw in that there is no narration or dramatic music. The second video is from the show ‘Destroyed in Seconds’
    If you watch the first video first, you can see the shockwave from the explosion spread across the ground, then you hear it. The second video, and any that seemed to be made into a TV production, have the sound sync up with the sight of the explosion.
    This always bothered me that they didn’t show the delay between sight and sound because I assumed most people would think that’s how sound works. I guess that’s exactly what happened with Flight 800

  19. tmac57on 31 Aug 2012 at 9:37 am

    Heptron-Nice example! That perfectly illustrates what Bronze Dog was talking about.Thanks.

  20. stereoblueon 01 Sep 2012 at 8:15 pm

    I heard a report on NYC radio that day that said the plane was shot down. I remember that pretty vividly as I was impressed by the boldness of that decision and wondered what sort of political fallout that would have in the days to come (its not everyday the military shoots down a plane full of its own citizens). It doesn’t surprise me that the news was wrong that day, but hearing that sort of report and then the subsequent retraction does lend itself to conspiracy thinking… so I’m also not surprised that accusations of a cover-up still exist.

  21. BillyJoe7on 22 Sep 2013 at 7:56 am

    I don’ t usually watch 60 minutes (because i don’t trust them to provide me with reliable information) but we had visitors over tonight and guess what they wanted to watch?
    And guess what the show covered?

    I remember reading about this conspiracy somewhere but couldn’t remember where so I googled it.
    There was a link to an article written by Stephen Novella, so I guessed it would be covered here.

    And how did 60 minutes cover it?
    Well, let’s just say that 60 minutes did not let me down.

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