Page 1 of 4

Re: Panther 92

Posted: Mon Nov 26, 2018 1:07 am
by ykachuro
A quick update on balancing the elevator — I’ve decided to go with the spring and not CW
My build had slowed down to a crawl for a few months until rnl, but I am catching up now.

Re: Panther 92

Posted: Thu Feb 15, 2018 8:59 pm
by bob_arthur
Hi Michael,
I am in San Clemente and would be glad to show you the full kit I am working on! I have finished the tail group and am almost finished with the tail cone. Next step would be to work on the forward fuselage and connect it to the tail cone. I would be happy to show it to you now or if you would prefer to wait until I have the full fuselage done and on the landing gear, We could do that.
You can catch me directly at...
bobarthur@mac.com
949.702.1232 talk/text

Re: Panther 92

Posted: Thu Feb 15, 2018 3:24 am
by Mkaratsonyi
Good evening,
I was fortunate to meet Yuri "92" through an airplane he was selling and stumbled into conversation about his Panther he is building. After a little research online I immediately fell in love with this panther!

If there are any builders or flyers of this beautiful Panther in/around/near the Los Angeles area I'd love to stop by and check out your plane or project.

Michael K

Re: Panther 92

Posted: Wed Jan 31, 2018 5:56 pm
by ykachuro
Rick, this is assuming my rational is correct and the balance is indeed making a differnce...

I think it is the piece of lead and two control arms — the install instructiins are in the rigging sectin of the BM

Re: Panther 92

Posted: Wed Jan 31, 2018 5:18 pm
by at7000ft
And since I will be flying my Panther from Denver up to Steamboat, Aspen, and Leadville occasionally I may add the CW too. (Is it just an extra lead weight or two purchased from SPA?).

Rick H

Re: Panther 92

Posted: Wed Jan 31, 2018 12:48 pm
by ykachuro
Bob, thank you! I hear you. My preference for a balanced elevator is to have that extra flutter margin, assuming that it was indeed the reason for Dan to require it on the short-wing version. The drawback, as you said, is the extra weight. On balance, I think I’ll go with the CW elevator due to my high altitude flying (TAS) and a fair chance of clear air turbulence in the mountains. The way I understand flutter is that high TAS creates the favorable condition for it, but it also needs a “trigger”, which might be a jolt of unexpected turbulence — both are more likely here in the Rockies.
It would be good to hear Dan sharing his design limits for flutter, and which part of structure is the limiting factor, but I am not holding my breath.

Re: Panther 92

Posted: Wed Jan 31, 2018 10:22 am
by woolleys
Yuri. I've flown both the short and long wing with the balanced elevator. Have about 40 hours of long wing time in a non counterweighted spring type set up. I found no difference in the flying characteristics of the two types. The elevator feed back and feel mirrored the CW type.

The 40 hrs. of spring type elevator panther was in the prototype trike. As with all trikes, they tendency to have a slight rocking motion over terrain if it's not smooth. Since I live on a grass stripe, taxing the trike saw the elevator bounce up and down if the stick was not held; this is not the case in the balanced elevator. In flying the Panther, I have notice one thing; and no effect on the flying characteristics. Since the horizontal stab. is almost symentical, the feed back through the stick below 100 MPH is light a smooth. During perfectly trimmed flight conditions during turbulence, the stick will float just a very small amount with your hands off the stick. I notice under similar conditions, with the spring type Panther, that the stick had a slightly higher amplitude to the turbulence. This was only noticeable hands off below 100 MPH.

I believe that Dan put the CW elevator on the short wing due to the higher Vne; 210 MPH. Several of the builders around our airport are going long wing with CW elevators. But we all do heavy aerobatics with Lycoming 0320's and will regularly push the aircraft to the Vne of 200 MPH. I am currently building another Panther that will be a long wing. I will most likely put the spring type system on that aircraft just to save the 4 or so pounds of weight. The other thought is the CG with the CW elevator, that has turned out to be a no issue.

Bottom line; heavy aerobatics, your location of high altitude and potential higher true airspeed, I would most likely put the CW elevator on. Vne is a function of true airspeed and out there in the mountains you could get to Vne before you know it. Dan could tell you what the projected flutter speed is in the Panther and I'm sure he set the Vne at a limit that gives you a very safe margin for potential flutter issues.

Re: Panther 92

Posted: Wed Jan 31, 2018 1:39 am
by ykachuro
Barry, thank you! With the experience behind you, you’ll be catching up to me soon!

Bob, thank you for sharing your experience and confirming what I’ve been thinking! At the moment, I plan to opt for a balanced elevator, however. Do you by any chance have a view on that?

Re: Panther 92

Posted: Mon Jan 29, 2018 10:40 am
by woolleys
Yuri. The build looks great; very nice work. On your decision to stay with the long wing, I don't think you are going to be disappointed. Having over 200 hrs. of short wing time on my Panther and almost a hundred hours of long wing time, the main difference is in the overall roll rate. Unless you are going to do heavy aerobatics you will be pleased with the overall performance of the long wing. Since you are going to be operating in higher altitudes the long wing will give you that exact performance at the lower density altitudes. Short wing provides a little less climb and slightly higher stall speeds, faster roll rates and if you use more rudder at slow speeds you can achieve the better roll rates.

Re: Panther 92

Posted: Mon Jan 29, 2018 12:22 am
by Barry
Looking great Yuri!! You are moving right along. I took a break from my Avid Magnum to work on the Panther. It is way fun!!!