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Reverse Thrust

Discussion in 'The Okie Corral' started by Texas T, Jun 24, 2004.

  1. Texas T

    Texas T TX expatriate CLM

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    Peaches' other thread got me thinking about this. I've seen several aircraft that could back up on their own and been on a few too. If you've ever flown on an MD-80 there is a strong chance that you've backed away from the gate under your own power.

    I've seen the Blue Angels support C-130 back up under its own power, and when I was watching Discovery Wings yesterday I saw the C-17 land, stop, back up, and turn around in about a 1500 foot space. That's pretty impressive for a plane that weighs over 250K pounds. :)

    Also got to see video of the C-130 that had been modified for the Iran Hostages rescue mission. It had about 8 sets of JATO rockets at various points around the fuselage because it was designed to land WITHIN a sports stadium and take off again. There is some video of a prototype (crashing) using this system at:
    http://www.theaviationzone.com/media/c130_credible_sport.mpg

    But I also saw some shots on Wings of another C-130 taking off using this system and they were airborne in about 100-150 feet. ;P

    Ahhh... just found some details (don't you just love google?):)
    http://www.spectrumwd.com/c130/articles/Credible_Sport.htm

    Here's a shot of it taking off:
    [​IMG]

    Close up shot of some of the rockets near the front:
    [​IMG]

    I'd like to know what the rate of climb was. :)
    [​IMG]
     
  2. Tennessee Slim

    Tennessee Slim Señor Member CLM

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    Anything with a thrust reverser (or reversible props) can back up under its own power, but there are three caveats:
    1) Reverse thrust kicks up taxiway debris (FOD) which then could get sucked into the engine intake or strike the props (engines are mounted too high on a Mad Dog, this doesn't much apply).
    2) A/C typically are loaded with their CG very far aft. Braking while moving backwards could cause the A/C to tip over and crash down onto its tail (so coast to a stop).
    3) Most airplanes have no rear view mirrors so it’s best to have clearance from someone who can see where you’re going (ground control).
     

  3. STYX

    STYX

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    2) A/C typically are loaded with their CG very far aft. Braking while moving backwards could cause the A/C to tip over and crash down onto its tail (so coast to a stop).


    hehe... a tail strike from breaking, horrible to explain that one to the chief pilot.

    I recall doing a reverse taxi-back @ memphis, are they still done?
     
  4. Tennessee Slim

    Tennessee Slim Señor Member CLM

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    I dunno, I've never worked from MEM. Does something wonky go on there?

    When I was with American Eagle (early ‘90s), we had a SAAB experience a tail strike coming in to BNA. The plane had flown in to Ft. Walton/ Eglin AFB full of Air Force types with duffel bags. The station manager failed to remove 11 of their bags from the aftermost cargo area, so the 25,000 pound A/C was 1000+/- pounds heavier (that's 1000 pounds tail heavier) on their return flight to BNA than the crew realized. The flying pilot got a stick shaker on round-out and the A/C mushed through and sort of backwards pancaked, hitting simultaneously on the mains and the keel. They executed a go-around and shot the second approach at Vref +30 (basically a flap approach at a no-flap speed). The second shot was letter-perfect but the Captain needed a whole pack of smokes before he was calm enough for his drug test.

    The VPS station manager was fired, as he well should have been.
     
  5. STYX

    STYX

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    hehe... wow.

    Yea, I really like the slabber-dog. I only have ~5 hrs in the Eagle sim, but I enjoyed it.
     
  6. Superfueler

    Superfueler Glockenplane

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    Until recently, pretty much all of AirTran's aircraft powered back from the gate using reverse thrust. I was on board a few times when this was done, and doesn't feel that much different than a normal pushback. I guess now that they are getting 737's, they are going to the normal method of using a tug and a towbar.
     
  7. M2 Carbine

    M2 Carbine

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    I backed up all the time.:)



    Sorry, nobody likes a smartass.;e

    ;f ;f

    [​IMG]
     
  8. ATL Peach Girl

    ATL Peach Girl ♥Meezers♥

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    <----flying on 4 MD-80's starting tomorrow and then again on 7/19/04........

    dayum things are packed too and I hate that!! I had no clue they could back away from the gate on their own.......
     
  9. Superfueler

    Superfueler Glockenplane

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    Wow, what is your routing to fly on 4 Mad Dog's in a row?
     
  10. Pat Beckley

    Pat Beckley Millennium Member

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    Reference backing up with reverse thrust: It is done with feet on the floor. Forward thrust is used to "brake" the backward movement. Any use of brakes would result in a tail strike, frowned upon by the maintenance department.
     
  11. NetNinja

    NetNinja Always Faithful

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    Yep Our Marine Corps KC-130's would only back up in rare circumstances.