Best CG for Acro

Discussion in 'Starduster' started by mreinh3233, Feb 18, 2018.

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  1. Feb 18, 2018 #1

    mreinh3233

    mreinh3233

    mreinh3233

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    So the CG range on my Starduster is 18-27” aft of Datum. What would be the ideal CG for gentlemen Acro maneuvers? Any and all of you Acro nuts feel free to chime in. Right now with full fuel and me on board it is about 1/2 inch away from the aft CG limit.
     
  2. Feb 18, 2018 #2

    TFF1

    TFF1

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    It's really not going to matter under your circumstances. Snappy things and spins like aft. Rolls probably middle, loops forward. That's for looks from the ground as much as pilot. It's all a compromise. How are you going to make flights. Comp pilots repeat like piano practice. Just going up for a loop and a roll, would set it up normal.
     
  3. Feb 18, 2018 #3

    Lotahp1

    Lotahp1

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    How’s your CG as fuel is burned off??? seems like you will Be out of CG range as fuel is burned off if you are only 1/2” from max aft CG with full fuel and you on board.
     
  4. Feb 18, 2018 #4

    mreinh3233

    mreinh3233

    mreinh3233

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    The CG does move aft as I burn fuel but I still have 45 or so minutes of flight time. I’m working on removing some belly ballast to get it better. Honestly if I flew from the front seat the CG would be about in the middle of the range. That would require a whole lot of work moving things around though. I’m not planning on doing any Acro until I’m more comfortable with the aircraft and can find a parachute that works for me.
     
  5. Feb 18, 2018 #5

    grassroots

    grassroots

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    These are aircraft specific issues and there is variation among different types. The snap/spin qualities of my stock S-1S improved slightly by getting the CG a little forward of the aft limit. Cleaner acceleration/rotation. Forward CG in a Pitts makes for great snaps and spins. I just can't get mine any more forward. RVs spin better with more aft CG than what'll you'll often end up with in a typical solo situation. Have a friend with an RV-8 who designed a clever way to add/remove CG ballast for doing competition spins. Not sure the connection between forward CG and loops but beyond a point forward CG is just adding stick pressure on the elevator. I don't know anything about Stardusters. Agree that for simple loop/roll acro, it really shouldn't matter.
     
  6. Feb 18, 2018 #6

    EAABipe40FF

    EAABipe40FF

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    Ahhhhhh, Houston we got a problem IMO.

    You might want to fix that and at least double check you W&B. (I recall when you got the airplane, I though you had a long enough mount?) CG will really get aft with a passenger.

    I have a similar issue with my Acroduster but not as bad. Of coarse my original intent was single place. I missed my CG by about an inch(aft) and added 13# to the gen. pad so that I would be within aft limits with ZERO fuel. My problem was that with passenger(Marcia) I would bust the aft limit with less than 12 gal./about 1/2 fuel in the AD2.

    BTW, the FAA inspector didn't like busting aft limit with zero fuel, would have required a warning placard if I didn't fix it.

    Jack
     
  7. Feb 18, 2018 #7

    EAABipe40FF

    EAABipe40FF

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    I have no idea how dangerous these airplanes might be with an aft CG, like spin becoming unrecoverable? I suspect the M6 and Pitts airfoils have a margin. I wasn't going to take any chances with the AD2....I am NOT a test pilot.
     
  8. Feb 20, 2018 #8

    Lotahp1

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    Do you have the 26” engine mount? In my Ranger powered Starduster Too you can be 300lbs and zero fuel and still be in CG if I recall. (Maybe its 250lbs...but I was thinking 300lbs. It’s been awhile since I’ve looked at the old W&B paperwork) In any regards. You need a longer engine mount or loose some tail weight. Is the battery forward? If it’s behind seat how about going to a EarthX. Etc etc. I’m very curious of your engine mount length
     
    mreinh3233 likes this.
  9. Feb 21, 2018 #9

    mreinh3233

    mreinh3233

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    It’s not 26”. That would help my CG if it was, but it’s easier and less expensive to lose weight than build a new mount and cowling.
     

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