Dennis suggested all the mods that went into this.
Never let a short story do when a long story can be told:
First some background. My Dad built a Sterling Spifire back in the early 1960's. It suffered from a flexible wing, flexible control system and a K&B Greenhead that usually ran away. Dad and my brothers flew it quite a bit while they were just starting out in stunt but the bird was not remembered fondly! I was 8-9 years old when they flew it, I just remember I LOVED that airplane!
Based on my memory, a couple years ago, I got a Sterling Spit off EBAY. The parts were already punched out, the box was pretty bad, so it was obviously a builder and not a collecter. I made an invisible change in the wing to make it stiffer but otherwise it is stock, used all the kit wood except the motor mounts. Meanwhile Dad had some great luck with stock Greenheads fitted with mufflers - seemed to settle them down. In short I built the Spit powered it with a Greenhead 35 - just the one on the kit box and just like Dad's! It is not especially light (48 oz) but it is stiff and has a good control system in it. I thought it would be fun to revisit the early 1960's.
The shock occurred when the airplane SURPASSED all expectations. The engine runs PERFECT (no exageration) and the airplane flies far better than Dad's did and far better than any of us expected - this despite way too thin of an airfoil, too much wing assymetry and way too short tail - and who in the heck ever used a Greenhead for stunt anyway? Because of all the wing offset it is prone to hinging, but that is not really a problem. The real revelation occurred one blustery day, in a turbulent wind that grounded the "modern" airplanes, the Spit handled the wind and turbulence with hardly a wiggle! I believe that it is BECAUSE of the thin elliptical wing. It is a little prone to wind-up but can be flown to minimize that - just like we would have done back when people actually know how to fly in the wind. Now with electric power I believe I can neutralize any remaining wind-up issues and make it just a little better yet.
The idea of an "improved/modernized" Spitfire has been rattling around my brain ever since I flew my Sterling. As you know Walter Umland recently came out with his version of the Sterling Spitfire. The Spit is a product of the late 1950's with then-popular design features, I believe Walter and his designer John Miller simplified the construction some. I recently shared the story above with Walter, had anticipated getting a short kit of one of his Spits and doing the deed. However, Walter took those ideas plus a few of his own and redesigned the Sterling Spit into the Seafire presented here. He is thus able to offer a full laser cut "Walter Umland class" full kit of the Seafire as well as the original Sterling Spitfire. I expect the lengthened fuselage and equal span wing will improve the performance and aesthetics while keeping some of those features that made the original model so special.
BTW John M made a reasonable suggestion to enlarge the stab - I do not think it is necessary and aesthetically it would be a disaster. The stock airplane flies fine with the stock 1/2" thick stab, on the much longer longer tail it should be even better. No one ever told Al Rabe he need a 25% stab on his Mustangs! (OK maybe someone did but he wisely did not listen!) The shape of the stock stab is right and it looks good with that wing.
BTW in another first, Walter has been designing in detail changes to try to accommodate the electric installation. I am anticipating using the Brodak Super Clown power system which includes a front mounted motor and a thin/wide/long 3 cell 3300 mah battery. The alternative to that would be one of the 4 cell motors which can use a short/squat battery that would have room to move fore/aft for fine tuning balance.
I am excited about this project and THANK Walter for taking it on...
Topic: New model survey... (Read 7882 times)
