Aileron Roll Aerobat

Discussion in 'Aerobatics' started by etemplet, Mar 2, 2016.

  1. etemplet

    etemplet Pre-takeoff checklist

    Joined:
    Oct 18, 2013
    Messages:
    141
    Display Name:

    Display name:
    etemplet
    Well... did my first few rolls in the Aerobat today. I have some aerobatic experience in a Pitts and recently took the Greg Koontz Aerobatic Training flying the Decathlon. Today was my first time alone and unassisted. LOL I have a few issues so advice and discussion would be interesting.

    I was taught to establish a 30 degree up-line, go do zero G or slightly positive and roll left with a little left rudder. I am not sure exactly when but I add right rudder when finishing up the maneuver. I am probably leaving out some important stuff but.... these are my basics.

    My big problem is that I am finishing with the nose pointed pretty far below the horizon. I have the speed on entry and it actually feels pretty nice but it gets ugly as it progresses.
    I did 4 or 5 today and got my cherry so... now I want to do them with some style and grace. Help would be appreciated.

    PMs work for me as well. Thanks in advance
     
    Last edited: Mar 2, 2016
  2. flyingriki

    flyingriki Ejection Handle Pulled

    Joined:
    Nov 25, 2008
    Messages:
    911
    Display Name:

    Display name:
    flyingriki
    In slow planes it takes a touch of push on the yoke when inverted to avoid that. Always worked for me in 150 and 172. In the EZ it makes the engine stumble and doesn't need it.
    Didn't they tell you that in training? Mine did.
     
  3. Stearman

    Stearman Pre-takeoff checklist

    Joined:
    Nov 27, 2015
    Messages:
    151
    Location:
    Dayton, OH
    Display Name:

    Display name:
    Stearman
    I'll second what flyingriki said. You might also try adding some small slow-roll inputs. That's what my instructor taught - something halfway between a "slow roll" (level) and an aileron roll (arc).

    Apologies for the vertical video...forgot to turn the camera.

    EDIT: Exactly how nose-low are you ending up? Like...45° or what?




     
    Last edited: Mar 2, 2016
  4. etemplet

    etemplet Pre-takeoff checklist

    Joined:
    Oct 18, 2013
    Messages:
    141
    Display Name:

    Display name:
    etemplet
    I was taught basic acro and the zero G aileron roll last month. It is different in the Aerobat and the Pitts which is why I wanted to learn the right way for lower performance aircraft without inverted fuel and oil. LOL I worry about negative G so not sure I should push. Don't wanna puke oil if I can help it. After reading and research it seems it is OK for me to be below the horizon 20-30 degrees. I just want to do this stuff correctly so it looks pretty. :) Thanks for the quick replies. :D

    Great video by the way. Reminds me of my training a few weeks back and the mistakes I made and still make.
     
    Last edited: Mar 2, 2016
    Stearman likes this.
  5. whifferdill

    whifferdill Line Up and Wait

    Joined:
    Jan 31, 2010
    Messages:
    921
    Location:
    NC
    Display Name:

    Display name:
    whifferdill
    Etemplet, you don't need to push. There are lots of ways to do aileron rolls. The easiest way is to pitch up a suitable amount with suitable airspeed, unload the elevator to 1G, and then apply full aileron with just enough rudder to counter adverse yaw. Freeze the elevator in that position. Hold those inputs until you've completed the roll, and then pull out of the slight dive. Done correctly, you'll be at the apex of your trajectory precisely halfway through the roll, and you will end pitched down the same amount you were initially pitched up, ending on your original heading. If you are starting to descend before the roll is half complete, you didn't pitch up enough. If you are still climbing halfway through the roll, you pitched up too much. There's nothing wrong with ending up nose low as long as you don't lose excessive altitude or gain too much airspeed. Don't correctly, you shouldn't lose altitude or gain airspeed from start to finish. This technique works in pretty much any airplane that will roll on aileron alone. The slowest rolling airplane I've rolled is a Stearman, and this works in that.

    That being said, there are things you can to do minimize the pitch up, and total altitude excursion during the roll. Pitching up and then putting the elevator in the zero G position does this. No rudder needed with a true zero G roll. Sounds like you've done those. The other way to minimize pitch up/down is to use a little top rudder as you pass though both knife edge positions, and to unload the elevator slightly inverted. You'll learn how much unloading you can get away with before the engine stumbles. There is absolutely nothing wrong with allowing this to happen, but if you're unloaded enough for the carb to stumble with fuel delivery, you're likely also unloaded enough to start dumping a little oil. There's nothing wrong with throwing oil as long as it's not excessive, but it's just a PIA to clean up.
     
    edo2000 and Stearman like this.
  6. etemplet

    etemplet Pre-takeoff checklist

    Joined:
    Oct 18, 2013
    Messages:
    141
    Display Name:

    Display name:
    etemplet
    Thanks so much for taking the time to explain this stuff. :D