Skybolt Flop Tube & Engine Failure

Discussion in 'Steen Skybolt' started by CapnWolfe, Jun 26, 2018.

Help Support Biplane Forum by donating:

  1. Jul 8, 2018 #41

    CapnWolfe

    CapnWolfe

    CapnWolfe

    Skybolt Driver Supporting Member

    Joined:
    Feb 5, 2018
    Messages:
    86
    Likes Received:
    37
    Gender:
    Male
    Location:
    Florida
    I ordered the 16" flop tube instead of the original 17"... there are a couple of adaptors on the end that put it closer to 17.75", and I don't want it to hang up. I tend to be pretty conservative on fuel reserves, so I'm hoping that will work. Comes in on the 9th and hope to install/test fly on the 11th... Fingers crossed! I'll also try and keep an eye on the fuel pressure gauge.
     
  2. Jul 11, 2018 #42

    CapnWolfe

    CapnWolfe

    CapnWolfe

    Skybolt Driver Supporting Member

    Joined:
    Feb 5, 2018
    Messages:
    86
    Likes Received:
    37
    Gender:
    Male
    Location:
    Florida
    So I got the new flop tube today and it came with an O-Ring that fits on the end of the brass flop tube... I wouldn't want the o-ring to come off, but the other brass was worn a bit on the end...

    Any advice to keep/toss the O-ring? Any thoughts?
     

    Attached Files:

  3. Jul 11, 2018 #43

    smizo

    smizo

    smizo

    Moderator Staff Member Moderator Lifetime Supporter

    Joined:
    Sep 7, 2009
    Messages:
    6,096
    Likes Received:
    3,212
    I glued mine on with proseal........ I also have a filter just before my electric fuel pump.......
     
  4. Jul 11, 2018 #44

    StinsonPilot

    StinsonPilot

    StinsonPilot

    Well-Known Member Lifetime Supporter

    Joined:
    Nov 24, 2007
    Messages:
    3,236
    Likes Received:
    664
    I'd keep it. Keeps the pick up from wearing the bottom of your tank.
     
  5. Jul 13, 2018 #45

    CapnWolfe

    CapnWolfe

    CapnWolfe

    Skybolt Driver Supporting Member

    Joined:
    Feb 5, 2018
    Messages:
    86
    Likes Received:
    37
    Gender:
    Male
    Location:
    Florida
    Test flight went okay... In fact everything seemed "better" ... had the wife along so didn't do any long-term negative-g but everything seemed good so far. Next time I'm upside down for more than a second I'll keep an eye on the fuel pressure and let everyone know how it goes...
     
  6. Jul 13, 2018 #46

    EAABipe40FF

    EAABipe40FF

    EAABipe40FF

    Registered Users Supporting Member

    Joined:
    May 30, 2009
    Messages:
    5,165
    Likes Received:
    973
    With due respect, A test flight with a passenger ?Not in my play book. Any flight after repair especially the fuel system is a true "test" flight in my honest opinion. This includes anytime a fuel line is even loosened. Too many cases of a mechanic not putting proper torque on a fuel line. YMM

    Jack
     
  7. Aug 11, 2018 #47

    n262ln

    n262ln

    n262ln

    Member

    Joined:
    Dec 12, 2017
    Messages:
    16
    Likes Received:
    5
    Gender:
    Male
    Location:
    Mebane, NC (5NC5)
    My inverted fuel issue has been diagnosed (30 seconds inverted and the engine quits). When draining the fuel tank I put the fuel valve in the position labeled "Open" which should have drained from the bottom of the tank. When fuel stopped flowing out of the gascolator I pulled the center feed of the lower tank (connected to the flop tube) and fuel started leaking out. Immediately screwed center feed back in and reconnected fuel line. Switched fuel valve to "Aerobatic" position and fuel resumed draining through the gascolator. Waited 5 minutes as fuel drained and again disconnected the fuel line from the flop tube. No fuel leaking from the center feed this time. Bottom line: the fuel valve had been labeled backwards! Would that all airplane issues were that simple!
     
    biplanebob likes this.
  8. Aug 11, 2018 #48

    biplanebob

    biplanebob

    biplanebob

    Member Supporting Member

    Joined:
    Aug 22, 2006
    Messages:
    946
    Likes Received:
    400
    Gender:
    Male
    Location:
    KLNS
    Great outcome !
     
    nemecek likes this.
  9. Aug 12, 2018 #49

    EAABipe40FF

    EAABipe40FF

    EAABipe40FF

    Registered Users Supporting Member

    Joined:
    May 30, 2009
    Messages:
    5,165
    Likes Received:
    973
    Those are the kind of things that kill people.

    But happy for the good outcome.

    Jack
     
    smizo likes this.
  10. Aug 12, 2018 #50

    Jwilsonphoto

    Jwilsonphoto

    Jwilsonphoto

    Registered Users

    Joined:
    Aug 27, 2006
    Messages:
    66
    Likes Received:
    15
    The large an fitting is connected to you flop tube and is your main fuel source, the small bottom fitting should run to your tank sump drain somewhere in your bottom sheet metal. Vent lines are in the front of the tank. I think the standard recommendation is to replace flop tubes about every 3-4 years. That is a McKenzie/Hall tank design and there are no baffles in the inverted sump. When I replaced my flop tube, the fitting had seized with the threads in the female tank fitting and I had to cut it out and heliarc a new female fitting in. I used a lot of thread anti-seize from that point on :)
     
  11. Aug 13, 2018 #51

    Ralsmark

    Ralsmark

    Ralsmark

    New Member

    Joined:
    Aug 12, 2012
    Messages:
    69
    Likes Received:
    32
    What is the design objective of having the "open" position of the fuel selector so as to bypass the flop tube? To circumvent loss of usable fuel if flop tube gets stuck in up position? Or to address broken flop tube hose maybe?
    Mark
     

Share This Page