Flying Wing -- 76" wingspan -- Maiden Flight Today
 

I built a 76 inch flying wing based upon the Northrop N9M. Scratch-built. The wing weighs 3 lbs 1 oz. It is powered by two Speed 400 motors (pusher configuration), two BECs and an 8 cell 2400 mAh battery pack. It will fly for 8 minutes at full power and about 12 - 14 minutes with throttle management.

Today was its maiden flight. Winds were out of the east at 15 mph gusting to over 20 and the wing flew great. No noticeable adverse yaw.

Many improvements learned with my first two wings (96 inch, single .46 size engine pusher version and 48 inch single engine electric) were incorporated into this wing. The elevons are longer and I have learned to build wings in such a way that most of the heavy stuff will fit into the nose.

Time to get some stick time on this plane while we design and build the 14 foot wing for Toledo 2004.

Jeff

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Congratulations, Jeff.

Looking forward to hearing more about it, and seeing your bigger one later. ...Cool.

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Looks graat and sounds like you got a winner. Better hurry though, Toledo isn't very far away!!! [&:]

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

I appreciate the encouragement. This is the 4th pure flying wing (pure = no vertical surfaces) I have built since last December. While I used John K. Northrop's patents to design these planes, there was quite a bit of "try and die" experimentation involved. What I have now is a pure flying wing that can be flown within the confines of a 600 foot x 300 foot field. There is plenty of lift for a normal person to hand launch this plane and have plenty of time to hit the throttle before it gently glides to the ground.

I built this particular wing so I could fly it at a local field, less than 1/4 mile from my home. Electric power allows me to spend more time flying and less time preparing to fly. Maximum stick time per flying session.

Now we are working on wing number 5....the 14 footer, twin engine glow.

Jeff

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Jeff...I really like the wing you built...I don't know if you remember the Klingberg wing's that were out several years ago built I built one and installed an Astro .05 FAI and was using Sanyo 1400 mah SCR batteries and a Corelli car type speed control and it was the most stable plane I have ever flow. It was semi aerobatic and I was getting about 5 minutes AFT, It was very easy to fly but it would disappear if you were looking at the cross section for very long in a flight but It sure was a crowd pleaser. I lost it at the grand opening of our flying field...it was real windy that day and I had it sitting on top of the motor on my truck charging the batteries when it was lifted off the truck and slammed into the parking lot. I looked it over real good and when flying it the next time the right aeliron came off and that was all she wrote. It would sure be nice if you had a set of plans ...I really would like to build another one someday.
C.W.

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

That is a beautiful aircraft. I love the lines and its purity. I can only imagine how pretty it must be slicing through the air.

Videos maybe?

PLEASE release plans for it and put me on your mailing list.

- Paul

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

PS. I'm curious if you could mix the throttles to the rudder channel somehow to get some yaw control?

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Paul,

Thanks so much for your comments and feedback. The wing does look very majestic in the air. There is just nothing like flying a pure flying wing. I quickly learned this spring and summer that when I take a flying wing to the field be ready to answer a lot of questions and be prepared to always fly in front of a crowd of spectators. It does attract attention because it looks so unique in the sky.

There is plenty of yaw control. When the CG is properly set and the correct amount of differential is mechanically set-up in the elevons, you will find the wing to have little adverse yaw. Plus, the spinning prop(s) provide yaw stabilization through the gyroscope effect. The CG range on this flying wing is 1/2 inch....and that is typical for a wing of this size.

I plan on offering plans for an IMAA-legal version of the wing. It will have at least an 80 inch wingspan and offer the builder powerplant options (electric or glow) and landing gear options (hand launched, fixed gear or retracts). Since I insist on building and testing everything I design, it will be this summer before plans are available. I will put you on my mailing list.

Thanks again for your kind remarks and feedback.

Jeff

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Jeff - I didn't mean yaw stability. I mean actually yawing the aircraft on purpose. Can you do that? If so, how?

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Paul,

Sorry, I mis-understood what you were asking.

Yes, through the use of clamshell drag rudders your can add yaw control to the wing. The drag rudders are are toward the tip of each wing. They open up and the wing slows down allowing the other wing to travel faster and yaw. Attached is a picture of a drag rudder.


Adding drag rudders does add some complexity. The ends of the wing get pretty thin and housing a servo small enough to fit and strong enough to operate the drag rudders is an interesting project. On larger wings (12 foot and above) this is not an issue.


So yes, yaw control can be added.

Jeff

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

So do you think a throttle mix would work effectively?

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Hi Jeff,

You are flying my kind of bird - all (or at least mostly) wing and engines pointing the "wrong" way.
What type of airfoil(s) are you using. My experiments have been limited to simple symetrical NACA types. However, I have never built a flying wing with the aspect ratio of the N9m.
Attached pic of my latest is about 3:1.
I salute you on your design abilities, that looong wing and all those ribs, outstanding work.

Scotty J

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

I don't know about controlling yaw with varying the speed of each engine. They did not use this technique on the full scale Northrop planes and they do not use this technique on the B-2. Drag rudders have been the choice for yaw control.

However, this is model aviation and you can do whatever you want. :) Experiment and enjoy!

Jeff

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Scotty,

Thanks so much for your kind comments.

I am using an Eppler 334 airfoil from root to tip. This is an airfoil made specifically for flying wings. It delievers high lift...and wow...does it ever.

Last week when we tossed the plane for initial CG testing, it flew for over 100 yards into a 10 mph headwind.

Jeff

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

That is fantastic! This sort-a-scale F7u glides like the lawn dart it resembles. But the design philosophy is different. It weighs in at 7.75 lbs. and is scary fast.
Not too many years ago a gentleman and his aircraft were highlighted in one of the major magazines. I recall it was the Northrop wing, used 4? .32 heli engines (embedded in the wing w/ ducted cooling and extension shafts to the props, custom retracts, two dozen? servos, and if memory serves it was 12-14 feet span. If you are interested I will attempt to find the magazine/article. No promises, I disposed of a dumpster worth of back issues recently.

cotty J

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Scotty,

You are talking about Dale Yaney who used to have a web page here: http://www.ivic.net/~spider/dale.html

His YB-35 (built in 1995) has a 12 foot wing span and was powered by 4 glow engines. I found him and pictures of his plane early in my research about 2 years ago. Beautiful plane!

Jeff

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

you could stick 2 or 3 super uber micro servos in the tip to move the drag rudder things. that way wou can get 150 in/oz in each tip, should be more than enough, (1 or 2 may even work)

also, i second the beg/plead for plans. thats a NICE bird. love to have one.

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

I want to third the request for plans. I'll take them as is. :)

As far as the yaw thing goes, I was really more curious if the engines could do it more than if there was a way to add a yaw control. I think if I built this model, it would not be one I would test the idea on. Too pretty and too much work. Maybe a small .061 version that is simpler and less time invested in building.

OK, so tell me where to send the check for the plans please. :)

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

I love it! Pleas put me on the mailing list. As you can see from my avitar, I fly without a stab (Evans Simitar Pole Star.) It's been beat into a post during a limbo contest, stepped on by my neighbor, and suffered a realllllly hard landing that ripped the wheels off, and it still flys. I look forward to your IMAA legal version.

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Flight testing continues on the 76" wing. I got two flights in today and I am able to get about 15 minutes of flight time out of the 2400 mAh battery pack. In 5 - 8 mph wind conditions the plane flies at 1/3 throttle and is a beauty in the sky. My photographer was unable to make it to the field today, but we hope to get in-flight pictures on Sunday afternoon, weather permitting. The two Speed 400 motors are plenty of power for now.

The IMAA-legal version will not be a difficult re-design. By increasing the length of the root and tip airfoils less than 1/2 inch, I can add another rib bay and the wing will be at over 80 inches. I'll be building the IMAA version while we build the 150" version.

Thanks for your words of encouragement and I'll keep you up-to-date on the progress of these projects.

Jeff

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Attached is a picture of Wing Version 2.0 (Version 1.0 was a prototype)

This one is powered by an OS .46 FX turing a 10x7 pusher prop. It has a custom rear exhaust machined by my dad. Fixed landing gear with 3.25" tires. It weighs 7 lbs. I cut my teeth on this plane and it taught me a great deal about how all wing aircraft like to be flown. First flight was March 2003. Flight testing during Spring and Summer 2003.

Jeff

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Jeff - I can't transport a larger version. I'd like plans for the wing in your first post if you release them. Even tech notes so I can build are fine. I don't actually need plans - just an airfoil, CG and washout or other important parameters. :)

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

dito, i have no room for big stuff (mostly limited to around 70 inches)

(i promise to put your RCU name on the wing :D)

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Jeff Like your project very much. Please put me on your list too. Thanks

RE: Flying Wing -- 76" wingspan -- Maiden Flight Today
 

Looks Great! Love those electric flying wings. Put me on the list for plans please. Thanks!

David McCracken