Richard Riley

The Vari doesn't require either an electric or mechanical fuel pump. It is a good idea to have at least one, if not both. The Long specifically requires a fuel pump. That was the core of the whole Bill Davenport debacle.

DeltaHawk says: Experimental aircraft firewall forward kit development is beginning. No indication of how many have been delivered, or how big the backlog is. If I were developing an airplane from scratch I wouldn't use it. County on a Lyc. It the DH comes along someday, great. We almost built a aircraft around the Thuria. Glad it didn't work out, now.

A 200 HP diesel for aircraft use would be a nice engine. Do you happen to know of any that are actually for sale? I don't mean an engine in development and are just around the corner. I mean an aircraft diesel engine that I can go trade cash for and put in the back of a truck and drive home. I've been doing this for 18 years now, and the most important rule I've learned is: Never design your developmental aircraft around a developmental engine.

Pnumatics can be used, some British airplanes have used pnumatics. There are some advantages. If there's a small leak, you don't care. You don't have to have a return line. On the other hand, if a line ruptures its' MUCH more exciting. Small high pressure air pumps are much harder to find. And there's all the stored up energy that you have to get rid of. If you have 3000 psi in a hydraulic line and you come to the end of the piston gear stroke, the pump turns off, the piston stops. If an air valve turns off, you still have 3000 pst trying to move the piston. So it's POSSIBLE, but it puts you into more basic design.

The Berkut hydraulic nose gear isn't strong enough to lift the airplane, like the Wright nose gear will. If you just want to save weight and cost, go manual.

Sadly, no. My most recent homebuilt project is just coming up on 8 weeks old. He's pretty demanding at this age.

HEY!!! I got 2 more years till I'm 50!!!

I'd suggest you grab the Berkut 3 view that's floating around on the web, blow up the side view to useable size, then draw a box the size of the Zoche engine profie. Put it aft of the firewall, make a rough guess as to the CG of the engine and how far back from the firewall it should be. Then draw 2 lines for the profile of the top and bottom cowl. Fiddle with them. See if you can get it to look tollerable while keeping the prop far enough forward so you don't get a prop strike on landing, and preferably with less than an 18" prop extension. (the gyroscopic forces get huge when you get that long".) 'Cause, we couldn't make it work, and we tried for a long time. And there's that whole the-engine-is-vaporware thing, too.

The only point where I disagree with Marc is on the fuel. Later airplanes, with molded wings, put about 15 extra gallons in the wings just outboard of the strakes. Beyond that, you could put about 50 gallons in underwing pods and for record attempts another 50 in the back seat. As to how to get one - they're rare. I'll sell you mine, but it's REALLY, REALLY, REALLY expensive.

If it ever comes to exist (and I would bet a year's paycheck against it) it won't fit well on a Berkut. You'd end up with the cowls going straight back from the firewall, curling around the cylenders and stopping around the prop shaft. The DeltaHawk is closer. But really, Berkut was designed around the Lycoming.

The Swings have wanted to sell since about 2000.

Best of luck.

The shape isn't patented. They can copy it all day long. However - it's going to be EXPENSIVE to bring a kit to market from scratch. Count on a couple of million. It would be cheaper to buy the whole Velocity company.

Yaw is driven by having rudders AFT of CG, not just away from CG. The farther aft, the smaller the surface can be and have the same authority. Gus McLeoud's velo had booms like what you're desrcibing

I've had a little experience with Berkuts. We didn't use wax in the molds. We used non-transferring silicon based mold release agents. It was a lot more expensive than wax. We used wax and PVA when making a mold from a plug. We were very careful to remove any trace of wax before sealing the surface and applying mold release. I've used perforated mylar as a release film between a laminate and the bleeder cloth, and never had a problem with it sticking to the laminate. I don't know why your mylar is sticking. I would never use wax on an epoxy surface that was going to get a subsequent bond. Wax dissolves into every liquid epoxy hardener I've worked with.

That is very interesting. Please, tell us more!

Glen Waters did something you might consider. He installed a diagonal from the front upper lip of the thigh support, right at the instrument panel, forward about a foot and down to the floor. Made a triangular section to help absorb impact. Just a thought.

Very nice Tony, the cross webbing on the upper fitting pivot arms is clever, I wish I'd thought of it. Are you going off the drawings for the pivot trunions? They're a lot more complicated than the A or H arms.

The A, H, T and trunions on mine were always 6061 billet - they were from the time prior to the cast parts. I made my own legs, used 7475 for the upper, with all the lightening pockets eliminated and the diagonal put back in, and went up to 7/16 pivot bolts. They're heavier than the old ones, but after John Danials broke his I didn't want them to be marginal. Since I was exiled, I haven't been privy to ongoing development and had to roll my own.

Tony - 1) Are you doing the "T" arms (that bolt to the H arms?) 2) Are you doing the pivot trunions? 3) Are you getting rid of the lightening pockets in the gear upper end? And are you aware of Dave's mod to the cast uppers that involved welding heavy plate to tie the two pivot arms together?

The layup schedules are not in the drawings. I'll share what I recall. There wasn't any real engineering done - basically, we started with the Long EZ sequences and made them all stronger and lighter with better materials and vacuum bagging. The basic sequence for the fuselage was 1 ply 7715 lengthwise, 1 ply DB090, 5 lb 3/8 core, and the same on the inside. There were reenforcements around the aft lip (2 extra 7725 plies), the longeron depressions( 2 extra 7725 plies), and the nose bumper (5 tapered plies 7725). There were 2 plies of Kevlar down the centerline in the aft half, under the outer glass. The rollover got 3 extra plies of DB090 both inside and outside. We learned to make all the laminates symmetrical, or the parts would warp as soon as they came out of the molds.

I've always figured the weak point was the cylender bolts.

The T-tapes for the spar bulkheads ARE overkill, but it's an elegant way of dealing with blind edges that need some kind of bond. I'd suggest you get a tube (Tubes? 2 tubes and a static mixer) of Pro-Set adhesive for the actual final installation of the spar forward face. It doesn't make much difference here - you could just use flox - but it makes for a significantly easier installation when you go close out the strakes, and you might as well get some experience with it now, on the little thing. And don't make yourself crazy with the blended winglets. When you're done, if you're still up for that last 1%, we can develop a good set of pen-nib fairings that will get you just as much as the blended would, for 1/100th the work.

Very, very impressive, Paul. I wish I'd known. I have a lot of parts tucked away that you could have taken molds from.

I'm patiently waiting for that audio, too. Tony, Barnaby Wainfan believes that a well developed pen-nib fairing will be at least as effective as a blended winglet, possibly more. James Redmon has an article in the Oct Central States about putting them on his airplane, he picked up 5 kts IIRC.