Please explain.

Discussion in 'Aviation' started by Henk, Dec 29, 2007.

  1. Henk

    Henk Active Member

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    How did the guns of a prop fighter's guns fire trough the propeller without damaging the propeller? It is something that I never actually could get to understand.

    For some it might be a stupid question, but please bare with me on this.

    How does it work?
     
  2. evangilder

    evangilder "Shooter"
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    I think it was the Germans that came up with a timing mechanism that stopped the guns from firing when the prop blades were in front of them. If I remember correctly, it was called an interrupter gear.

    I did a quick search and found this:
    Interrupter gear - Wikipedia, the free encyclopedia
     
  3. Soren

    Soren Banned

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    The beauty of the gear :D

    [​IMG]
     
  4. magnocain

    magnocain Member

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    The early fighters also had metal plates on the back of their propellers (that helped a bit), but when they tested it on the ground it killed the observers.
     
  5. Nikademus

    Nikademus Member

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  6. Graeme

    Graeme Well-Known Member

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    Called the Roland Garros deflector system.

    [​IMG]
     
  7. Henk

    Henk Active Member

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    Thanks mate I appreciate it very much.
     
  8. ccheese

    ccheese Member In Perpetuity
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    FYI, a lot of planes with rear facing gunners had an interrupter cam attached to the gun..... to keep you from shooting off your own tail.

    Makes you wonder how many B-17 gunners pumped slugs into other aircraft
    in their formation ?

    Charles
     
  9. comiso90

    comiso90 Active Member

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    i believe it was the Dutch
     
  10. Marcel

    Marcel Well-Known Member

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    Actually it was Anthony Fokker, working for the Germans in Germany. More precisely it was one of his german designers :lol:
     
  11. Nikademus

    Nikademus Member

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    Indiana Jones and his father could have used one in the Last Crusade. :lol:
     
  12. wilbur1

    wilbur1 Active Member

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    Fokkers idea ran of the eng. camshaft that was timed to the prop. the allies captured one and vickers(i believe) modified it. at one time they were trying to make an automatic fire at the same rate as the prop turned.
     
  13. Njaco

    Njaco The Pop-Tart Whisperer
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    from Warplanes Air Battles of WWI - Beekman House 1973 pg 32

    On April 18, 1915, an event which was to have extreme importance in the history of aerial fighting took place. A well-placed rifle bullet fired by a rifleman named Schlenstedt, defending Courtrai railway station, fractured the petrol pipe on a Morane-Saulnier monoplane in which the well-known French pilot Roland Garros was attacking the line. Garros landed, but before he could set fire to his machine, it was captured by the Germans. The secret was then out: Garros who had destroyed several German aircraft in the previous few weeks, was found to have a machine gun able to fire forwards through the airscrew.
    ....The propellor, which was armoured with steel deflectors to avoid damage from the aircraft's own bullets, was shown to the Dutchman, Anthony Fokker, whose M5 monoplane was then undergoing service trials, and within 48 hours Fokker was claiming to have invented an interrupter gear to prevent bullets from hitting the screw. But then Fokker's brilliance as a demostration pilot was equalled only by his unscrupulousness and his flair for public relations. The irony in the situation lies in the fact that Fokker's new monoplane, which went into service as the E1 had been designed only after Fokker had aquired and analysed a Morane. Furthermore, Saulnier had himself invented and tried an interrupter gear but had discarded it because of unreliable performance of service ammunition. He saw steel deflector plates as an improvement and he may have been rigth in the early war years. 'Bad rounds' continued to bedevil machines with interrupter and sychronising gears on both sides throughout the war. This, rather than official stupidity, could possibly be the reason why the notion of using the airscrew to fire a gun had not been adopted before, though it is highly unlikely.
     
  14. SoD Stitch

    SoD Stitch Banned

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    Yes, this is the system used in earlier forms of interrupter gears, pre-electric triggering. Later (WWII) versions of "interrupters" would simply delay the electric firing signal from the cockpit to the machine gun/cannon when the prop was in the way; this was a simpler (and lighter) version of the "interrupter gear" on WWI fighters.
     
  15. wilbur1

    wilbur1 Active Member

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    Oh i had it backwards,knew it was some thing like that . Thanks nj and sod
     
  16. Njaco

    Njaco The Pop-Tart Whisperer
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    Wilbur, no worries. I think you have it somewhat correct as after the E1 became a menace, the Allies were able to capture one and the secret was out. Gonna check my references.
     
  17. Crumpp

    Crumpp Banned

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    Many WWII era fighters used an electrical solenoid instead of a gear
     
  18. Njaco

    Njaco The Pop-Tart Whisperer
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    Here ya go Wilbur.

    from "Airpower" by Stephen Budiansky pg 64

    " But the Fokker's reputation was, at least for a time, more important than any reality. "You were as good as dead if you as much as saw one." was the solemn belief of British fliers; rumor held that it could fly twice as fast as any Allied plane. The Germans helped keep the myth alive by forbidding Fokker pilots to fly over Allied lines so that its secret would not fall into enemy hands. When the British did finally capture one in April 1916 ( a second came into French hands in October 1916 when a German pilot landed by mistake in a fog at a French airfield), not only did the Allies discover the synchronization gear but they also found that the Fokker's speed and Maneuverability were nothing exceptional. The captured plane was flown in mock combat against a Morane fighter and "a cheer went up" from a British squadron on the ground below as the French plane outpaced the German."
     
  19. wilbur1

    wilbur1 Active Member

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    I knew i read that somewhere thanks nj:D kinda makes you wonder how long it would of taken allies to get it:shock: or the overall outcome of the air war
     
  20. Njaco

    Njaco The Pop-Tart Whisperer
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    The funny thing is, from what I've read, is that there were actual patents on these systems but never taken further because the ammo was unreliable.
     
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