Abbra first fly report

Mon Jun 6 14:08:34 AKDT 2005

The wing does not act in a lifting matter when in knife edge. The fuse is now the lifting body. The wings will act like the vertical fin.  

I took NATs advise and increased the positive incidence in my plane and cured two issues.

1. less pitch to the belly in knife edge 
2. seems to lock in better in level flight and inverted flight

Downlines are still ok as are up lines.  I have to hold a little down in inverted but I can mix that with a little more ATV or try to move the c.g.  Right now I wouldn't change anything but hte ATV for the feel when inverted.

It doesn't hurt to crank in a few turns and try it, you can always go back to your original setting.

Wayne Galligan
  ----- Original Message ----- 
  From: vicenterc at comcast.net 
  To: discussion at nsrca.org ; discussion at nsrca.org ; discussion at nsrca.org 
  Cc: Nat Penton 
  Sent: Monday, June 06, 2005 4:14 PM
  Subject: Re: Abbra first fly report

  I think I should try to explain more.  Right now the wings are set to 0.75 degrees. That requires down trim for level fly.  When the plane is flying knife edge that down trim causes to go to the belly.  Therefore, if I decrease the positive incidence, I will decrease the amount of down trim and hence the tendency to go to the belly in knife edge.  Again, I can see it but I could be very wrong.  

  Experts in trimming, Is this correct?

  Vince

    -------------- Original message -------------- 

    Nat,
    That is correct so when the plane is in knife edge there would be less tendency to go to the belly so I will need less up mix with rudder.  Am I right? 

    Thanks,

    Vince

      -------------- Original message -------------- 

      Vince, if you decrease the wing incidence you will need more up elevater mix for the knife edges, not less. Let us all know how it turns out.          Nat
        ----- Original Message ----- 
        From: vicenterc at comcast.net 
        To: NSRCA 
        Sent: Friday, June 03, 2005 9:52 AM
        Subject: Abbra first fly report

        Abbra glow version 1st. Fly report

        Yesterday, June 3, 2005 I flew my Abbra the first time.  For those interested in the equipment please see Bob Pastorello web page.  The version that I flew is the glow version using OS160 engine.  Final weight is 9 lb 14 oz.  I know that I could reduce the weight a little more by using lighter wheels and smaller receiver.  It is OK for me since this plane is my first 2 m class plane less than 10 pounds.

        First Fly impressions:  Clearly the most constant speed plane that I ever flown.  I can fly closer to show a better presentation.  It is going to take some time for me to get along but definitively I like the change.  Please understand that this is my first wide body plane.  For those flying already wide body planes probably won't be a big change.  The down lines are a pleasure to watch.  I felt as a pilot that I have more time to make corrections.  Slow and snaps rolls are fantastic. Landing is a pleasure.&n! bsp; Not sure yet about spins since I did it once only.  I really didn't like the break.  I think I need a little more up elevator since I lost some travel amount after the elevator trimming.  

        First Trimming Impressions:  As soon I took off I knew that I need down trim.  I got fixed and finish with 28 bits of down trim in my JR 10 X radio.  Also I finished with 4 bits of left trim.  Ailerons and elevators were set up for 10 degrees travel.  After the first landing, what a landing it was a 10 using the old rules, I checked the elevators and found that one half was a little more up than the other half.  Also, I found the same problem in the right aileron that was a little more up. When I say a little is almost difficult to see at naked eye.  Definitively the plane was tellin! g me that I need a better mechanic.  This was clearly mechanic error (me!!).  I checked the CG and the plane looks fine now.  If you ask me where it is the CG now "I will say I don't know".  I am one of those guys that check the CG in the air.  I put the battery behind the firewall so I knew that I was a little nose heavy.  The plane requires a little pressure when flying inverted.  Right now I need more time to finish CG adjustments.  My taste is a little tail heavy so I will start to move the battery but I want to correct the positive incidence first.  I will check the actual locatio! n for those that want to have the information.  The rudder was set to about 30 degrees.  I think is OK.  I did the master schedule one time.  I feel now that I am OK for travel.  Probably, I will need to get a little more up for the spin but I did it only once yesterday.  In the second fly, I did finish with 8 bits of down elevator.  I know that my plane was set up for 0.75 degrees positive incidence.  I also know that you can order the plane now using 0, 0.25, 0.50 and adjustable that you will need to install.  It is clear to me that 0.75 is too high and probably I will go 0.25 in my next Abbra to reduce the down elevator trim.  The positive incidence and the elevator trim causes that the plane requires rudder with up elevator mix to hold knife edge in both sides.  In this regard, it is clear the plane requires opposite aileron also.  This is not a surprise to me since I never had a pattern plane that didn't require any mixing during knife edge.  I still tweaking with rudder mixing with elevator and rudder.  The final information will come in the future.  My next step in trimming the plane is to try to reduce the positive incidence to 0.25 degrees to minimize the mixing and the down elevator amounts.  Also, I will increase to 12 degrees the up elevator to improve the break on spins.  ! On lateral balance I don't think that I have to adjust.  The plane tracks very well in loops but I need to check a little more.

        Tomorrow, I will have a judge calibration section.  The judges will tell me if my impression of fantastic landings, snaps and slow rolls are realistic. 

        Vicente Bortone

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