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Aircraft Accident 19 JUL 1989

  1. May 7, 2007 #1
    1989 (eighteen years ago) an aircraft droped down its fan disk. And After that it has difficulties for landing and crashed on the gruond and more than 100 people killed.
    The disk was not found several months. Indeed by simple physics rules it is very easy to find the location of this disk. Because they know the speed of aircraft, speed of wind, frequency of disk etc..
    And several months later one farmer found the disk accidentially.

    The question is: if physics dont find answers to such kind of problems why it exist. That is the point. What einstein or newton said is ofcourse impartant but if it not solve the peoples problems there is something wrong with that.
    yours sincerely.
  2. jcsd
  3. May 7, 2007 #2

    Doc Al

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    I want to know when physics will finally solve the riddle of the lost sock! After all, socks have mass and should be governed by the laws of physics. Until this question is answered, what's the point of this so-called "science"? Bah!
  4. May 7, 2007 #3


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    The physics behind it may be simple, but when something explodes, the variables involved in determining where the pieces will go make the actual prediction very difficult - especially when the disk itself buries itself in the ground and you need to be standing over it to see it (you have no idea how many golf balls I have lost while being certain of where they landed!). We didn't know:

    Exactly what the wind was doing.
    Exactly the direction/speed at which the disk was thrown,
    The aerodynamics of the disk (how fast was it spinning?)

    Other complicating factors: high altitude and speed made for a large error margin (large debris field).
  5. May 7, 2007 #4


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    That's not quite the whole story.

    The main reasons it took so long to find it were

    (1) If fell into a field of corn (maize). It's hard to see a piece of metal 200mm thick, in the middle of a field of corn 1m or 2m high.

    (2) When it fell, it buried itself in the ground, which made it even harder to see.

    (3) The farmer didn't "find it accidentally". All the farmers in the area had been told about it, and sent pictures of it, so they would know what it was and that it was important to report it.

    (4) It was found when the corn was harvested, which is exactly what the accident investigators expected would happen. There was no point destroying thousands of pounds worth of crops just to find it a bit quicker, so they decided to wait.

    Even doing a simple "projectile" calculation to find where it might have landed would be hard, because there is no way to know what happened as it fell off the aircraft. If it broke away quickly, it would have had an acceleration of something like 500 m/s^2 forwards (because it was providing most of the thrust of the engine. If the shaft breaks the disk and blades are still turning and generating thrust, and the thrust is now just accelerating the disk). If the disk had broken into several pieces when if came off the plane, the pieces would have unknown velocities of hundreds of m/s relative to the plane. It's not quite so simple to do the calculations as you claim it is.

    Actually I once spent 6 months trying to work out where something that fell of a plane might have landed. The plane was flying over the Amazon rainforest at the time. We never did find the bit that fell off. I guess it's stuck in the top of a tree somewhere. Maybe if that part of the forest gets felled for timber, or burned clear and converted to a sugar cane plantation, it will turn up then...
  6. May 7, 2007 #5


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    Science solves many of the problems that people have. Just look at all the modern technology around you. There is no way you would have any of it without modern science. The reasons for why the disk couldn't be pin pointed so easily have been explained above.
  7. May 7, 2007 #6
    Hmmm... Maybe it has something to do with building the airplane in the first place. Just a crazy thought.
  8. May 8, 2007 #7


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    Sancho has been making some stellar first posts - heroically challenging the meaning of "General", generously inflating the value of "the parameter "2" ", pitting Newton against Einstein in a celebrity deathmatch, and now this.

    I fear for his online longevity. :biggrin:
  9. May 8, 2007 #8
    It takes talent to make a statement so ungrammatical so as to be immune to criticism. Anything I could attempt to say is obviously useless against someone who would type the above.
  10. May 8, 2007 #9


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    The fact that a DC-10 could land at all with no hydraulics and the use of thrust changes on either side's engines to somewhat guide the plane and still have more than half the people walk away from the crash is apparently lost on the OP as well.
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