What a pleasant surprise to see your article in Sport Aviation. it reminded me of my old days when I constructed the same Stits Skycoupe Model SA-7D in the cellar of my house and had my first flight, April 1972. My original engine was a Franklin Sport-4 supposedly rated for 125 horse power, but was more realistically a 100 horse power engine. After about 5 years of flying I replaced the Franklin engine with a Lycoming 0-320, 150 horse power engine. That engine made a world of difference. It gave me a cruise speed of about 130 MPH. I flew the plane for 25 years, all landings were scheduled, and the airplane #N3834, is now on permanent display at the ESAM (Empire State Aerosciences Museum) Rt. 50, 130 Saratoga Road, Scotia, New York, 12302.
1. I would very strongly suggest that you do a rough assembly of the airplane and put it on scales to calculate the center of gravity (CG). My experience indicated that the Stits design produced a CG moment that was too far aft. As a result, I had to redesign the engine mount to move the engine forward and also relocate the battery to the engine compartment to bring the CG within the design limits.
2. I narrowed the nose fuel tank because it pushed the instrument panel too far forward, essentially putting the instrument panel in your lap. As you know, you need a certain amount of depth behind the panel to accommodate the instruments. A wing fuel tank was added of about 7.5 gallons to replace the lost capacity of the smaller nose tank
3. My plane was rigged for night flight, so if you have this in mind, be sure to make provisions during your construction phase.
Also, be sure to include provisions for your radios and their antennas. I located my receiving antenna in the vertical tail fin and the transmitting antenna in the belly. The transmitting antenna was located in the center of an aluminum sheet, filling a section of the fuselage. This aluminum plate acted as a ground plain which is necessary for good transmitted signal strength.
4. Wing struts, I used streamline tubing.
5. Flight characteristics: a stall is gentle and must be aggravated, otherwise normal flight is very stable and well behaved. Approach speed for landing I found to be 80 MPH over the fence and below that speed the airplane sinks really fast. It is important to maintain speed until the runway is under the tires.
I hope these suggestions might be of some help to you. I would be more than happy to assist you in your project in any way. Please feel free to contact me with any questions you might have. I am very interested in watching your progress on your website.
William (Bill) Buyak
Lehigh Acres, FL 33936
Bill Buyak with his Skycoupe in the Empire State Aerosciences Museum (www.esam.org)
Above: The nicely-appointed and well finished panel in Bill's 'Coupe gives us something to shoot for.
Below: The Buyak Skycoupe at a fly-in in Vermont some years back.