# Lightning Aircraft?

Discussion in 'General Experimental Aviation Questions' started by pequeajim, Jan 14, 2007.

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1. Jan 14, 2007

### pequeajim

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Has anyone heard of these guys? I saw it at the Sebring Expo and was pretty impressed with its lines and the fact that it comes in kit form with a builder's assist program.

The aircraft can be built as a LSA or experimental. They slow it down by putting VGs on the wing, prop pitch and remove the gear fairings. It is very fast and slippery.

The one thing that I am curious about is the advertised specifications? I don't see how they come of with some of the specs that they do. 17:1 glide ratio with 90 sp ft of wing area? With that same wing area they claim a useful load of 625 lbs?

With those little wings, I can see how it should be fast, but even other aircraft like the TECNAM, and CTs don't have that kind of glide ratio, (CT is 14:1)?

I'm not saying that these guys are not reputable; I am just questioning what they are saying about the specs and performance of the airplane.

2. Jan 15, 2007

### N2T18S

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That is a beautiful plane. Looks like a Pulsar. The spec page listed 25' wings and 1400 lb gross. You will have to build and set the gross at 1320 to fit LSA. You can't change gross after construction. The kit is $50,000 with a motor plus accs.. You might consider this. (I think the 582 Rotax Pulsar fits LSA now). http://donateyourplane.com/pulsar_xp.htm Looks like a pretty good deal. The Dragonfly is another model that fits LSA if you slow it down. There was one sold/given away on Ebay for$3600 with a motor. These planes at least have a track record and a new builder can start practicing without a second mortgage. I have a Task built Dragonfly kit I hope to build next for the ELSA class. But, it still may not fit. I didn't see where Lightning had their plane certified LSA. They just said it would fit. I would want to see one registered LSA before I spent \$50,000 plus.

Bob
N2T18s

3. Jan 15, 2007

### orion

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An interesting new airplane. I haven't heard of this one but they do show quite a bit at their web site to make at least a few cursory observations. First, it looks like a slightly modified copy of a Lancair 235 or 320. There are minor differences and it does look to be using a different wing section (although I'd have to confirm that), but overall it seems similar enough to at least raise an eyebrow.

They show quite a few pictures of the parts and the various sub assemblies so you can get at least an idea of what's involved in putting this together. It looks to be a fairly standard structure although one or two areas would need a bit of a closer examination in order to see the details.

But looking through all the presentation materials all I could think of is: Sloppy. If these pictures are truly representative of their parts and their work I'd probably recommend a deeper investigation before committing. The first picture I randomly selected was that of the rudder assembly. Even a cursory glance shows that the molded part came out of the tool with surface wrinkles - almost as if the material bunched up and separated from the tool. Also, looking at the sides of the fuselage, that too looks to be uneven. The surface seems to be poorly shaped (look at the light reflections) with surface discontinuities that make it look like the surface of an orange. It is possible that this is misleading and maybe it has something to do with the tool prep or the primer coat, but quite frankly I can't think of anything that would cause this except poor tooling or maybe poor quality control during fabrication.

Another area that might cause some concern is the wing spar - possibly the strength, but more so the manufacturing itself. First of all, it is a combination of graphite and glass. While feasible, generally this type of structure is not recommended unless one really understands how the materials behave together. The significant difference in stiffness between the glass and the graphite makes each component see the loads a bit differently, with more of the load going to the stiffer component of the structure. If this is not understood in the design of the part, this could lead to eventual structural problems.

From the layup standpoint, if you look at the root of the spar, the graphite ends petty much at the root rib. Why? And then the way it is laid up, it is very sloppy, with untrimmed fibers running every which way. Not really a good presentation and certainly not something that most companies would want to use as a demonstration of their skills.

Regarding their performance numbers, they look to be something that they took from some analysis program without really verifying what they were presenting - I'd prefer to see something that's a bit more accurate and flight proven. I too would be a bit skeptical of several of the claims, although it is a clean airplane and some of the numbers may not be too far off. The glide ratio? Yea, I'd question that too. Even without the prop it sounds way too good to be true.

In short, if you're interested in this airplane I'd suggest that you hire someone in your area that really knows small airplane design and engineering issues and have him or her go through their factory with you.

4. Jan 16, 2007

### pequeajim

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Thanks Bob for your input. I really was not interested in the aircraft for LSA, but only commented on the fact they believe that they can make it fit the catagory. I would build it as an experimental and to be as fast as it will go.

Orion:

Thanks for the excellant points. It helps to have a trained eye look at the pictures and pull out some of the details that you have mentioned.

Are you going to Sun n Fun? I plan on being down there and would love to hook up and get your opinion of the aircraft as I know it will be there too.

5. Jan 16, 2007

### orion

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Unfortunately with my current schedule I don't think I'll be able to get away for some time yet. I'm currently designing and building a new Reno Unlimited racer, which is certainly taking up a lot of my time. In about a week or two I also expect to to be starting a contract of redesigning the structural and manufacturing details of the Berkut in order to prep it for production. And on top of all that there is another possibility coming a bit later this Spring or so, which is the development of a new business jet. Potentially a good year (although I'm not counting my chickens just yet) but it is unlikely that I'll be able to go anywhere for some time. The only getaway I might get is the Reno races in September. But then those are the benefits and drawbacks of being self employed.

6. Jan 16, 2007

### pequeajim

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Understood...

I am going to schedule an initial trip to the production facility some time next month. I will take the first pass myself and if still interested, will find the right qualified individual to go back with me before I buy.

Thanks for the great input and good luck with you schedule in 2007. Make sure you save a little time in there for a life huh?

Jim!

7. Jan 17, 2007

### CNCRouterman

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Re: Berkut rework??

Hello Bill,
It seems to me they pulled the plug on it a while back, and the website suggested a dim future for returning to production. Does this mean that they have found funding to make a go of it again? I hope so; I liked the looks and performance numbers. I would put it at or near the top of my list of canard configs.

I would infer that your involvement would entail streamlining the manufacturability and or assembly aspects?

Best wishes,
Eric

8. Jan 17, 2007

### wally

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Berkut???

Hey now that is one heck of an airplane. I remember seeing the TV adds featuring it flying - Discovery Channel maybe? And then that next year I got a pic of me in front of it at Sun-N-Fun.

And working on an unlimited Reno Racer? Nice! I "may" dream a bit more about racing in the biplane class some day out there - that is if I ever get mine flying...film at 11. EAA and FAA Inspections are next.

Wally

9. Jan 17, 2007

### orion

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I don't know enough about the inner workings of the Berkut program to give you any useful info (and I signed a non-disclosure agreement regarding their planned use). In general though, it now is owned and funded by a new group of investors who are looking to build several aircraft for their own commercial enterprise. Whether the plane will go back into kit production or not, I'm not sure.

10. Jan 21, 2007

### macosxuser

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Rocket Racing League or whatever that was? :speechles:speechles:speechles Darn NDA

11. Jan 21, 2007

### orion

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Actually I don't think so, although I wouldn't rule it out. If the NDA allows, I'll post something more later. If not, you'll have to find out when every one else does.

12. Apr 18, 2007

### Topaz

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Hi Orion,

The latest AvWeek has a little blurb in the NewsBreaks section with a photo of a Berkut-derived UAV called "Mobius". This wouldn't be your mystery derivative, would it? :smile:

13. Apr 19, 2007

### orion

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Ahem, err, I'm not allowed to say.

Last edited: Apr 20, 2007
14. Apr 20, 2007

### macosxuser

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Darn, whats the point of an airplane like that when you can't get in and FLY!

15. Apr 24, 2007

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