stab tip plates

[Bootlegger]

 I'm gonna try stab tip plates on a Sig Sky Ray to see if the elevator has more "athourity".
 The size that I'm using is 1.25" tall and 3.5" long, and include the stab and elevator.

 What I am asking is y'all's thoughts about using them and the sizes that I am gonna install.
  Thanks for your thought's and suggestions...

 

[Phil Krankowski]

Make sure they are on "straight" as in parallel and with the desired offset.  Those are large enough to replace or override the rudder.

Phil

[Tom Niebuhr]

Bob Gieseke and I talked about Ed Elasick and his Impala. You might remember that the Impala was the FIRST stunt with three rudders. Ed did this since he was influenced by the Lockheed Constellation. The Impala turned quicker than many stunters of it's era.

At the time Bob was trying the tip plates on his Bear. Bob turned to me and said "You know, Eddie had something!"   Enough said.

[Brett Buck]

I'm gonna try stab tip plates on a Sig Sky Ray to see if the elevator has more "athourity".
 The size that I'm using is 1.25" tall and 3.5" long, and include the stab and elevator.

 What I am asking is y'all's thoughts about using them and the sizes that I am gonna install.
  Thanks for your thought's and suggestions...

   It's worth a try. I have found that the control authority (torque around neutral) is fine as is on mine. What it seems to lack is maximum pitch rate, which is why I enlarged my elevator and move it a lot. If I was going to change it, I would shorten the tail, and then enlarge the stab/elevator to get the same tail volume coefficient. That would retain the control authority but increase the maximum pitch rate. Having said that, I think anyone who has flown it, or seen it fly, on my recent West Coast Skyray Tour, would agree it flies pretty darn well, even as it is!

   I would expect the tip plates to improve the sensitivity around neutral but not tighten the ultimate corner radius, but I don't know for sure and I wouldn't let that interfere with your experiment. Only one way to know for sure.


      Brett

[Bootlegger]

 Phil, do you think that if I reduced them to 5/8" tall and keep the 3.5 length that it would not be as apt to over ride the rudder?
 I don't want to compound the problem...
 Tom N the same question to you and you also Brett.
  Ans again thanks...

[Phil Krankowski]

Just make sure they are straight or offset in the desired manner is all.  Draw out some guides, or cut a paper template.  This is a "measure twice" situation, just the reference points are not in line but offset.

If they are large enough to effectively alter and contain the airflow over the surface then they will be large enough to cause yaw.

Phil

[Brett Buck]

Phil, do you think that if I reduced them to 5/8" tall and keep the 3.5 length that it would not be as apt to over ride the rudder?
 I don't want to compound the problem...
 Tom N the same question to you and you also Brett.

  You need to put them on straight, regardless of the size. You should remove any rudder offset, too.

     Brett

[jim gilmore]

I have a question here on the whole tip plate thing.
If the tip plates were noy large like the twin rudders of a Gemini, or stunt Machine ,
Buy just a flat ridge of say 1/4 or 5/16 larger than the actual stab and elevator outline. Would they still provide the same benefit yet not  over power the actual rudder ?

[Phil Krankowski]

I have a question here on the whole tip plate thing.
If the tip plates were noy large like the twin rudders of a Gemini, or stunt Machine ,
Buy just a flat ridge of say 1/4 or 5/16 larger than the actual stab and elevator outline. Would they still provide the same benefit yet not  over power the actual rudder ?

I don't know.  Containing air at deflection might not work with such small plates.

Just put them on straight!

Phil

[Brett Buck]

I have a question here on the whole tip plate thing.
If the tip plates were noy large like the twin rudders of a Gemini, or stunt Machine ,
Buy just a flat ridge of say 1/4 or 5/16 larger than the actual stab and elevator outline. Would they still provide the same benefit yet not  over power the actual rudder ?

     That will probably do something but not very much.

  I wouldn't worry about "overpowering the rudder". All they will do in yaw is to slightly improve the stability in yaw and keep the noise pointed forward a little better. There shouldn't be any rudder offset to speak of, but if you do make it adjustable, its an *extremely powerful* adjustment, and something that moderates the effect might be helpful, and make the adjustment more forgiving. On my airplane, it borders on too sensitive, and a half-a-turn on a 2-56 quick-link (maybe 1/32" at the TE of the rudder) is a huge change.  The same issue is why you rarely see a properly-adjusted Rabe rudder - because the required movement in many cases is so small that it's almost impossible to achieve, or is overcome by slop in the mechanism.

     *If it was me*, I would just put them on straight, and then see what happens. I don't think it will hurt anything, and will likely make a substantial change in the pitch response (which may or may not be an improvement).

      Brett

[Bob Reeves]

An opinion from a different view point.. Even if they do work I don't like not being able to see the elevator from the center of the circle.

[Brett Buck]

An opinion from a different view point.. Even if they do work I don't like not being able to see the elevator from the center of the circle.

  That is certainly an issue, and it seems that the number of incidents of "backwards" controls is much higher on Olympic-style airplanes.

   As an aside, I did it for the first time ever at the Bob Palmer meet a few weeks ago. The usual causes - in a hurry, disrupted routine, and unfamiliarity with the particular set of equipment. Fortunately this was with the Skyray, in Profile. Just got off the ground, landed very hard, broke prop, and it went through the wing. I taped it up on the circle, replaced the prop, flipped the lines around, signalled for start - 547.

    Brett

[john e. holliday]

I remember my Olympic with the stab plates made it almost impossible to see the elevator.   I would look at the flaps.   Remember they are moving opposite of the elevator.  Cure for reversed controls is to leave the up clip on the plane.

[Randy Cuberly]

At least a couple of "Top Level" Guys from Texas seem to think that some like these work pretty well...They are both National Champions!

  

Randy Cuberly

[Brett Buck]

I remember my Olympic with the stab plates made it almost impossible to see the elevator.   

  I didn't even have that excuse. I was in a hurry and didn't look.

    Brett