Wingtip into Fence

Discussion in 'Maintenance Bay' started by brien23, Mar 18, 2023.

  1. brien23

    brien23 Cleared for Takeoff

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    Cessna 172M left wingtip ran into fence destroyed plastic wing tip, hit hard enough to bend pipe on chain link fence. Has anyone found secondary damage like rear spar, carry through or other places to look for secondary damage.
     
  2. Craig

    Craig Cleared for Takeoff

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    Check for buckling in the skins, binding of the aileron or flaps and bowing of the lift strut.
     
  3. GeorgeC

    GeorgeC Administrator Management Council Member

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    Ask an A&P IA.
     
  4. xyzpdq

    xyzpdq Filing Flight Plan

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    Check the rear spar behind the fuel tank for buckling.
     
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  5. Magman

    Magman Cleared for Takeoff

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    As per preceding , check at the rear edge of the tank access panel.

    You may ( hopefully you won’t ) see a bump about the center of that edge

    if it’s a typical Tip Strike. Since the Rear ( aka False ) Spar is only .032 or .040

    thick it will likely buckle if the Plastic Tip is damaged.


    It may be wise to open some inspection panels and squirt the protruding screw

    threads with your favorite penetrating oil. There are various methods to remove

    the difficult screws; my preference uses a Rivet Gun.


    At once time Cessna sold a Rear Spar Repair Kit which addresses the repair

    perfectly. The last one I used was very difficult to find. EARLY Cessna Service

    Manuals include the repair but some later ones have it crossed out.


    Whoever is doing the repair should verify correct “ Wash- out” using the simple

    tools in the Sheet Metal Repair section of the SM.


    Some Tip Strikes tend to be overlooked and a full post- strike inspection is

    not performed. I know of a 150, Cardinal and an Archer that were flown BEFORE

    discovering the extant of the damage. Likely because the Plastic Tip was still

    intact. The Archer tore out the forward Attach Point so the still installed wing

    could actually be moved. The Cardinal fuselage was buckled.
     
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  6. Racerx

    Racerx En-Route

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    Wonder if that archer would have passed the Eddy current inspection for the spar bolt holes...
     
  7. Magman

    Magman Cleared for Takeoff

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    The Archer presented entirely different from the others.

    With the Forward Attach torn out ( as in “ Bearing”) you could move the wing a

    small amount. The real surprise here was finding the baggage compartment floor

    buckled! I’m sure it would have additional loads on the spar holes.

    Note that the Airframe Components website has some excellent short vids on

    topics like this. Sorry; a link is above my pay grade.


    Note: I just checked their site and it has been revised. It appears you must click on

    You tube channel to see the full list.
     
    Last edited: Mar 18, 2023
  8. frfly172

    frfly172 Touchdown! Greaser! PoA Supporter

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    A thorough by someone who is familiar with the airplanes would seem to be in order. Find an IA you are comfortable with using.