DaveyMo,

Great! ...and keep it going!

I live above 4900' above sea level, and that affects both engine output and aerodynamic performance noticeably. I occasionally fly a 30+ year old plank 1/2A on a TeeDee and whatever 15 or higher % nitro fuel I have. Lines are 0.010 solid wire about 42' long, and no problem. Wing is 1/8" sheet about 200 sq in - you wanna see flexing dihedral? Weight is just over 4 oz, dry. It's an original, but generally inspired by Dick Sarpolus' similar models, many of which appeared as articles in the old Flying Models magazine.

All-flying stabilator tail - which, btw, Sarpolus never used. VERY maneuverable, yet comfortable steady level flight and stable return from maneuver turns. I use either a Sullivan multi-hole handle at wide spacing or a handle I carved to match the model. Perfect (brand) aluminum 2" bellcrank, 1" stabilator horn radius. The proportion from bellcrank-to-pushrod radius to stabilator horn radius 'tames' response to comfortable.

For heavier models, the altitude is a more serious problem. A Classic-eligible ENVOY (by Alan Aldridge, from a magazine article plan ) flies very well at 10.5 oz dry, but consistent power from a TeeDee is hard to assure up here. Re-dimensioned the control linkages when I built it. With reliable power, it feels as solid as my .35 and .40 stunters, just doesn't pull as hard. ENVOY is about 225 sq in.. Same line length and material - it isn't line length that's the problem. I'm tempted to chop the model up to put a NorVel or AP into it. A bunch of work - it would also need a larger tank. If I get really motivated, I might build a similar, but own-design, 1/2A stunter for "modern" power and Spiderwire-type lines. I've found that my own designs fly at least as well as - often better than - comparable models in the same categories...

John, I'm sorry that my trying to understand things troubles you. It's part of what I enjoy in the hobby. If I tend to see math that applies to our situation, that might just help another flier understand a bit better, why not? Just doing a thing the way it has worked before can become boringly repetitive, to me anyway, and not solve some typical quirks. Some low intensity studies I've done over the last 50+ years work beautifully for me, and adapted well for flying buddies over the years. That adds to my own enjoyment and confidence.

We share, after all, a hobby, each in our own most enjoyable ways... no?