A Fast Delta?
 

"Super Vulcan" is a custom built design with carbon fiber - Foam composition with a 38" ws. Carbon Fiber spar wing tip to wing tip. Carbon Fiber laminated liteply nose to tail structure. It is powered by a VR-DF .91 ducted fan engine which will turn on the ground 20,600 rpm. Unloaded in the air it is likely another 2,000 to 3,000 rpm. The prop is a 7.9"x 12 custom ground APC 11x12. The plane weighs in at 4.8 lbs ready to go but without 12 oz of fuel onboard. Flight times are typically 4 to 5 minutes, but you will likely have flown 14.16 miles per flight. Vertical climb rate has been calculated at over 9,500 feet per min! Vertical is easily unlimited at half throttle. The plane is my design with everything including the tank tucked away inside the wing. There is a special bay in the wing for a GPS unit, but I haven't got one yet. Note the plane is longer than the "Diamond Dust" to make it a little more stable on speed runs. The span is a little wider too. The airfoil is just 1.75" thick at the root. The spinner is cowled to meet the fuse and this winter I have built a fiberglass cowl to go back to the clamps on the tuned pipe. All electronics and servos are inside small bays in the wing

I haven't had this plane clocked yet but it is considerably faster than any plane I have flown. It has to be upward of 230+mph. Maybe a tad faster coming out of a long dive. Once I get a GPS going, I will have very definite results. The bottom of the plane is clean and black in color.

This plane flies off of a large stable dolly and requires a ground roll of around 75' to get it airborne. Yes it is very loud and I do wear hearing protection when it is started. The ultimate "Scream Machine!"

Delta
 

Hey Blue,

I thought you looked familiar! Nice to see you back in circulation!

Ever since I started fooling around with my Diamond Dust I wondered what had happened to you since I first found your web site with a Google search long ago. I often wondered if you were still playing around with the high-speed prop planes since your page hadn't been updated in so long.

That's a very cool looking machine you've got there. I hope you break all the records with it!

Loud...
 

I can see why you would need hearing protection there...you are using an unmuffled pipe according to that picture.
Is that the only way to get to that powerlevel, or is a muffled pipe just heavier?

A Fast Delta?
 

I use the unmuffled pipe for maximum power + there is a 3 oz weight difference. When you take the trouble to throw out all the weight possible, it doesn't make sense to add a pipe that is a little heavier. I also fly this plane only a few times a year so I'm not a noise problem at our flying field.

Bob Holmes

A Fast Delta?
 

I use the unmuffled pipe for maximum power + there is a 3 oz weight difference. When you take the trouble to throw out all the weight possible, it doesn't make sense to add a pipe that is a little heavier. I also fly this plane only a few times a year so I'm not a noise problem at our flying field.

Bob Holmes

A Fast Delta?
 

Nice looking plane Bob,,looks like another winner.. I talked to the fellow that makes the DD and he told me he use to make a larger DD ..I think he was just teasing me,because when i asked for particulars about the plane he clammed up like a mussel.. Why mention to me a plane and then when asked about it,,he says nothing,, To me thats not very friendly but thats only my opinion..

Very Nice
 

Very Nice plane. I love it! I have been thinking of making a coro delta with carbon fiber reinforced leading and trailing edges, and I am going to use the amount of sweep in your plane for more stability.

A Fast Delta?
 

Nice Job. Is your CofG at ~11% of MAC or greater?

I am planing on trying a blue foam wing covered with kevlar or glass. What did you use for covering?
I was intending to keep the maximum thickness to 1 inch at root, and max span 35 inches, with a 45 degree sweep.
I have never worked with foam wings before. I have been using coroplast wings for my deltas in the past.
Do you think I need to add spars, or will a few additional strips of carbon fiber 5.6 oz X 1inch on top help to stiffen the wing?

Thanks for any help.


regards
Todd

Re: Fast Delta
 

Hi, I just finished scratch building a fast F117 stealth starting from sheeted foam Zagi wing cores. It really screams on a Norvel 0.25 with an 8x6 prop. One of the fastest at our field. WS is 35", Length is 45", and AUW is about 2 lbs. Its a bit rough around the edges (I'm new to scratch building) and not exactly to scale, but its really a great performer. I'll fine tune it this winter and try to get some plans drawn up by this spring. Can't wait till it warms up around here!

A Fast Delta?
 

jdbusyguy


that really looks good! do you have any other pics of it?

Re: more Speedy Stealth pics
 

Hi, here are some more pics, showing the sheeted Zagi wing with filler foam and engine.

Re: Last Speedy Stealth Pic
 

Hi, here's another view. I crashed her pretty bad today :( Everything was going great then when I was coming in for a landing I lost complete control. The crash broke the muffler mount off as well as part of the engine where it bolts to the muffler. I'm not sure if this can be repaired. The plane is still in pretty good shape. The worst thing is that I'm not sure why I lost control. Did the tank empty thereby moving the CG back too far? I did find that the right wing's hinges were all broken off, but this could have happened during the crash??? Or maybe the cold caused the hinges to snap in the air?

Delta Wing - F-117
 

The Stealth design is a really hard delta wing to fly. The stall charactersitics are horrible. The Elevon on landing gets blanked out by the large delta wing and the flow over the wing is not laminar on my stealth making the elevons very inaffective. Did it stall? Mine breaks in a stall very abruptly. It also takes about 100' to get out of a power off stall.


I have built three F-117s to date. I still have my first .40 size proto-type. It was powered with a .46FX and it has retracts.



My Second one is nearly like my third one. I completely trashed my first one on the first flight. I have photos of the crash as it happened and it scattered parts for 190' from the original impact point dead center on out concrete runway. (measured distance!)

It was powered with a Moki 2.1 and weighed in at 32 lbs.

This is the one which is still flying built from blue building foam. WS is 84" and the Length is 9.5'. It is a handful to fly. It also has retracts and the wedge front causes down force on the nose greater than the elevons can correct for. Hence the plane will continue to lose altitude until you pull back on the elevons even at full up rate. It takes over 300-400' to re-gain control when this happens. Very un-nerving to say the least.

Sorry for the B&W photo.

Blue Skyy

A Fast Delta?
 

Sounds like it's quite a challenge to fly...I like that.

I once heard that the only thing keeping the full size F-117 in the air is the computers in it. I'm told this thing is completely unflyable by hand...

I don't know if all this is true, but I've seen one from up close (first time it appeared on a show in Europe, it was surrounded by over a dozen guards, armed to the teeth) and it really does not look like a jet.
I can imagine a model that size exhibiting difficult flying behaviour as well...

Very impressive model, by the way.

Re F117 / Delta Stall
 

Blue Skyy, your stealth looks awesome! That thing is huge, it must get mistaken for the real thing! Was your plane in one of the RC magazines last spring? I saw a picture of a big one like yours and it inspired me to build mine.

Mine too does have a tricky abrupt stall when I tried it with a full fuel tank. Thanks for the tip! Its nose dropped very quick but I was able to recover pretty well. With an empty tank (aft cg) maybe its stall is much worse? I didn't get a chance to try it yet. But before the crash it seemed to be moving to fast and level to stall at that time, it just seemed to roll to the right a bit, and then go sideways, then it was all over... like a leaf in the wind. Earlier I did want more pitch response from the elevons and thus added a V-Tail / elevator servo to use in addition to the elevons to give me more vertical leverage. This really helped a lot, but I had to widen the tail angle more like a normal V-tail to be more effective instead of at the scale stealth angle. Maybe this approach will give you the additional pitch response you are looking for. It seems like the more scale you build the less flyable it is.

A Fast Delta?
 

Yes I had a F-117 in 2002 March issue of Model Airplane news. The one I crashed. The latest one Shown above was in Model Aviation last May if I recall correctly.

Your F-117 has a more radical sweep angle than mine, which I learned with my first .40 size. The blanking effect of the large Delta surface is likely worse on yours than mine. I elected to alter the shape for a more gentle sweep for an easier to fly wing.

You probably experience an even more radical stall on your F-117 than mine I would guess. I also have the operating exhaust deflector, even through it doesn't deflect any exhaust, just airflow over the back region between the wings for extra elevator. I don't notice a difference in stall whether the tank is full or not on the large plane but the .40 feels it a lot. It's especially true on take off. I've seen 600' out on take off before I begin my first turn. Even then I'm only a hundred feet in altitude with a full fuel load and holding full back stick.

Are you on the sticks constantly? Both my F-117s are a constant balancing act even with the use of gyros to help compensate for droping wings due to wind gusts. The gyros will help take 50% of the fatigue out of a flight, especially until you get it up to speed when things begin to get easier to manage.

You say yours is fast... What's your speed estimate?

My .40 makes maybe 50 or 60 mph at best. The 2.10 Moki is much faster at maybe 80 to 85 mph at full throttle. It was never meant to be fast, just thrilling to fly. Seeing that shape in the sky cruising by is the most awesome feeling! That's what this hobby is about no matter what you fly.

Blue Skyy

A Fast Delta?
 

The stall effect of a highly swept delta really concerns me. My earlier .25 stealth prototype had less wing sweep and was a real joy to fly. It was very maneuverable and yet I could hardly stall it when I tried. At most it seemed to mush along nose high. At times I could put it into a really nice slow flat, almost stalled spin. It could kind of autogyro to a flat landing. I built this new version with much more sweep mostly for looks and hoping to get the same characteristics.

Thinking back on the flight, you are probably correct in that it probably suddenly stalled, thereby causing my loss of control. I have a Zagi flying wing, which will go into a similar "Death Spiral" if stalled just right. I will have to wait till I get the engine fixed before I can try more experiments to see what can be done. Hopefully something simple like moving the cg fwd and adding washout will help.

This little stealth definitely takes full concentration and is really exciting to fly, and definitely fast enough for me. Though not nearly as fast as some of the ships on this forum, I estimate it to run between 80 and 85-mph tops. Easily more than twice as fast as a trainer. For good aerobatic response I set the elevon mixing to have twice as much up elevator throw as aileron (+40/-20 degrees for "elevator" vs. +/- 20 degrees for "aileron"). V-Tail "elevator" throw is about +/- 25 degrees.

Stealth Delta Back Again!
 

Hi, my .25 F117's is back in action! I replaced the broken crankcase and muffler, and decided to move the cg fwd 3/4 inch, increased the V-Tail throw, and gave it a try today. How exciting! I couldn't get get off the ground in this snow after several attempts, so in desperation and much fear and stupidity I hand launched it. I got very lucky... she stayed level and climbed most beautifully. WOW! I still could perform nice tight loops at full throttle with the cg moved forward, and while cruising at 1/4 throttle its stall was much nicer. Kind of a wobbly nose drop easily recoverable in about 20 ft. Time went by so fast I ran her out of fuel and can in dead stick. With the cg this far fwd the best glide I could get with the stick full back was about a 30 degree decent (I forgot to try switching to high rates). It landed a bit hard and fast but no damage was done. :) Thanks all for your info and helping me to decide to change its stall characteristics!

There's still some winter left so I may try making one last version using a mid engine pusher configuration similar to Balsa USA's Enforcer. I'd try to hide the engine as much as possible under the canopy. Not sure if its worth the trouble.

F-117 with Gyros
 

I don't know if Gyros, are a bad word around here or not, but if you built a real scale F-117, and flew it with roll AND PITCH ! Gyros. Keep it above a minimum speed, you would be flying it like the full size aircraft. It might really be nice. I wish I could scratch build!

bobbdd

A Fast Delta?
 

Nice to hear you have it back in action with a successful flight. I pretty much fly mine scale. Mine has no aerobatic capability. It will do a loop, but it just doesn't appeal to me with this type of plane. Of course everyone has their own agenda. Would really like to see how you would do with a mid engine version of a stealth. I tried a rear engine version, and to get the CG right it took way too much nose weight. Something like 8 lbs total weight on a .40 size plane. So I went tractor with it. Photo is attached. Engine sets between the tails.

Blue Skyy

A Fast Delta?
 

Blue Skyy, your .40 size plane looks great too. Do you also have a photo of the 40 size tractor version? Did it require gyros to fly well? I've been thinking of ways to hide the engine better on mine, and tried flipping it on its side but didn't like the way the fuel seems to flood the carb and starts to drip out the muffler when its not running. It also seemed more difficult to tweak-in to peak performance on its side. I may try to remake the canopy to shroud the engine better before trying a mid-engine version. The pusher style really looks much better but the extra nose weight kind of kills it. What do you think? Either way they are fun and that is what its all about.


JD

A Fast Delta?
 

Sorry I don't have a photo of the 40 size tractor anywhere. That one suprises me. I thought I had photos of all of them. I don't have an engine in the .40 size anymore. I pulled it and gave it to a friend to use. The .40 does have Springair retracts, and looks real nice with the gear up. The F-117 is certainly a neat plane to see in flight. Nothing else compares to it's look on a flyby!

Blue Skyy