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.

Not to get to far off subject and just thinking out loud, is there any reason the mains and front gear can't be air operated as air is used for the blow down system? I'm building my own retracts, (not started yet) and am looking at all possibilities. I'm thinking hydraulics can apply more pressure size for size than air and is not used for that reason?

Press on

T

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.

My bad, Richard....my point was he didn't understand your level of involvement. Will you maybe make it to Columbia for the fly-in in a couple weeks?

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!!!

Well, I guess mine would be an "experimental" a/c then, like all the rest;)

 

I would have to do some research and modification to the cowling, right? And the prop shaft could be extended to lengthen the cowl and streamline it a little more.

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.

anybody know about the progress of this motor? I want to put it on a Berkut to utillize its full potential. Is it still vapor-ware? hope not.

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.

Promising news: http://www.msnbc.msn.com/id/24100365/

 

This is also very surprising:

 

I hope it all turns out well.

The Swings have wanted to sell since about 2000.

You are correct. Starting from the bottom up and doing all the tooling/molding/jigging is going to bear a cost in time and money. Thankfully, that phase is all but completely done.

 

The aircraft is at market, and is buildable currently.

 

Thanks.

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

Lynn

 

All I can say at this point is. There is more than one way to skin a cat. you use your methodology and I'll use mine. I'll put my layups against anyones anyday. I just don't have the time to teach an old dog new tricks.

 

Tony

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.

I have a question for all that have been following along here. I may have a very unique opportunity to purchase the new all billet aluminum Berkut upper gear legs, trunions, A , and H arms and actuators for those of you who want drybread gear. This offer would be for a very limited production run. I will have pics of the gear for my Berkut next week. the new Berkut gear are good for a 3400lbs gross weight airplane with a safety factor of 2. The upper gear are CNC machined out of 7075 billet with stainless bushings. the A and H arms are billet as well. . These gear are not cheap, but if you have the means. I highly recommend grabbing a pair. This post is purely for getting an idea if there is a need for the gear. Also would anyone be interested in a pre-molded berkut nose with bulkheads as a retrofit for the long Ez? These are really good looking retrofits for the Long Ez's. All orders will have to be paid in full for the landing gear and noses. (if there is enough interest)

 

Tony

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?

I'm wondering do you remember layup schedule for the Berkut fuselage or is that possible to find this info in the Berkut drawings because I've not bought these drawings yet (so I'm not sure).

Mak

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.

If you look up Zoche's patents, their connecting rod scheme is clearly illustrated.

 

I suspect that their connecting rod is the choke point in their design, as it is so far out of the ordinary !

 

JCP

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.

Here is the finished T-Tapes

 

Pic 1) T-Tape on the inboard spar rib.

Pic 2) T-Tape on the outbaord spar rib

 

 

 

Lynn

 

One other thing. The T-tape layup was in lieu of the micro "shelf" that runs along the top and bottom of the spar cap. Which probably would've taken just as long to do.

 

Tony

Very, very impressive, Paul.

I wish I'd known. I have a lot of parts tucked away that you could have taken molds from.

Just play "Enjoy Yourself", written by Herb Magidson, sung by Todd Snider, and you'll get the gist of the presentation.

 

Or wait a while until I get the recording, like for the years before.

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.