**EPP Peregrine, FFF-Eagle, Dragons and other Bird Planes** - RC Groups
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Nov 08, 2008, 11:12 AM
Lee's Avatar

**EPP Peregrine, FFF-Eagle, Dragons and other Bird Planes**

I have always liked planes that look like birds. This thread is starting with a new EPP design but I would like to get links to all of the great bird threads here no matter how old. If you have links please post them and I will add them to the list. I have already started to move them to Post #3.

The FFF Eagle has had a strong following so please look at the instructions on post 46 and 48 and painting in post 431 for more information.

Here is a link to a Dragon idea. https://www.rcgroups.com/forums/show...&postcount=987

If you have built a bird plane that has not been shown here please post pictures and videos and give us some information. If you have links to bird silhouettes and coloring that would help in design and color please post them.

The falconers in our area get together every February and show their birds and have contests. It draws quite a crowd. For the last two years they have invited me to drop money to the kids and fly a RC demonstration. Last year jokingly I went up and did the maneuvers that they were trying to get their falcons to do. To say the least it went over quite well.

This year when I go back I will have my own RC Peregrine to show. The Q-Eagle was the first design I did to prepare for the 2009 competition. This is the second but much more true to life than the Q-Eagle. I have had the help of Scott (an artist and engineer) who helped fit a high performance plane in a bird silhouette and who is offering to do the final paint job and the falcon event "Utah Sky Trials" chairman Patrick who is a falconer. He is helping me keep the plane as birdlike as possible.

I initially tried to build it without the rudder but it was uncontrollable. Although the rudder looks funny on the ground, it looks great in the air. It gives me a good side profile and blends in well with rolls and loops.

The Peregrine flies like a pylon racer. It's easy to fly. I have a lot of movement in the surfaces making it more sensitive than most people would choose to fly it. It could easily be toned down for an intermediate flyer. It feels fast but is only flying at WOT 45 MPH with the BW 1300 with a 7x6 and amazingly the same speed with the BP21 and a 6x6 prop although the climb is better. It wants to fly fast and loves aerobatics. It may be the quietest powered rc plane I have ever owned.

The Peregrine has a 50" span. It flies best if it is built light and flown with a CF2812 and a smaller prop or a BW1300 and a 7x4 or 7x6 prop. I have used from a 750 3S lipoly battery to a 1350 3S lipoly. Several people have flown it with a 2S (2 cell) battery and a larger prop to keep it light and quiet. The plane doesn't need much power to fly and much of the time I fly it at half throttle. Keep it light and get the CG right and it will fly like a trainer.

We are presently redesigning the Peregrine and have sold our stock on hand.

When it is ready to start production we will post the new plane on our home page at http://www.crashtesthobby.com/

This is the most complex wing I have ever cut. Posts 4-8 of this thread are a building tutorial showing how the plane is built.

The second video is the latest prototype that is painted in falcon colors. (There is no sound on the second video.) The third video shows the inverted Y tail prototype, the forth and fifth videos are of the maiden flights and testing. Forgive the seagull paint job. It's only a prototype.

RC EPP Peregrine (3 min 51 sec)

EPP Peregrine #3 11-08 (3 min 55 sec)

Falcon #1 Prototype (3 min 50 sec)

EPP Peregrine Prototype 11-08 (3 min 26 sec)

Peregrine with Elevons 5-09 (4 min 10 sec)

EPP Peregrine at the Practice Field. (3 min 23 sec)

Peregrine Power Slopen' 09 (4 min 6 sec)
Last edited by Lee; Jul 01, 2014 at 03:40 PM.
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Nov 08, 2008, 11:13 AM
Lee's Avatar
More on the Utah Sky Trials



This is their web site.


And a map to the flying site.


This is a journal entry for the 2009 Sky Trials.

During my RC Peregrine flight my RC EPP Peregrine got attacked by one of the competing trained falcons. The real falcon hit my RC plane falcon hard when it did a stoop (200+ mph dive) coming out of the sun. I saw it with barely enough time to cut the throttle to protect the bird. It took out my plane and rode it to the ground with 400+ spectators giving a standing "O". The falcon then hunched over it like it was going to eat it.

There were 10 falconers and falcons competing. This bird hadn't been real obedient or performed well had flown off and they were getting out the telemetry to track it and try to retrieve it. No one knew it was back over our heads with a lot of altitude. It saw the RC plane come up and dove at it and basically killed it.

It got the peoples choice award at the falconers banquet later by more than a 2 to one margin over the birds that actually did what they were trained to do.

There were photographs taken but the sun was wrong for video camera so there isn't a video. I told them I would let the falcon hit the plane again to get it on film. See the pictures below of the falcon hanging onto my plane.

Second note answering questions

I have flown for the Utah Sky Trials for the last 3 years. They know me and keep asking me to come back so I don't think I hurt their feelings too bad. I fill in the slow time when they have problems with a bird to give the crowd something to watch.

I saw one of the leaders of the event today and he is the one that told me that I was part of the peoples choice award at the banquet.

The falconer that owns the falcon seemed upset at first then the humor of the whole thing hit and he was laughing with the rest of us. The bird stayed on the kill. It is a trained bird and didn't release it until the falconer got to it and gave it a yummy dead starling for a reward.

I have flown with birds before. Last year we were trying to drop bait from an RC plane for the falcons in flight and I had already decided that I would kill the motor if any birds were even close, even if it costs me the plane. The motor was off so quick the prop is stopped in the pictures that were taken while the plane was still in the air in the grasp of the falcon.

The Division of Wildlife Services for the State regulatory management for falcons was present too. He wanted to get copies of the pictures to show the people in his office. He was laughing with the rest of us. He said I was the only person flying a falcon that didn't need a permit. It was obvious it was the bird that was the aggressor not me.


Last edited by Lee; Sep 02, 2017 at 02:35 PM.
Nov 08, 2008, 11:13 AM
Lee's Avatar




30" Kits at: http://www.2dogrc.com/ecommerce/os/c...d87a27916a6c0:

48" kits soon to be available at: http://www.dreamitrc.com/

See Posts 46 and 48 of this thread for great instructions and post 431 for painting ideas

The plans are here in this thread. Here is the 42" version plans. Look at posts 59 and 98 in this thread.

For the 56" version plans look in posts 46 and 49.

This video shows how well the KF FFF birds can fly.


KF Swift




This is a adaptation with wheels that has some possibilities


(German) excellent flying birds


Bird with videos











Here's the web page: http://www.stenulson.net/rcflight/soarbird.htm

here's the RCGroups SOARBIRD thread: https://www.rcgroups.com/forums/showthread.php?t=589905


Here's the original thread: https://www.rcgroups.com/forums/showthread.php?t=701120


Painting the EPP Eagle: https://www.rcgroups.com/forums/show...90#post8203490

EBay link: http://shop.ebay.com/items/_W0QQ_nkw...romZR40QQ_mdoZ


This is the thread: https://www.rcgroups.com/forums/show...=631950&page=5


Thread: https://www.rcgroups.com/forums/show...=643081&page=2













Hammerhead Shark shows anything is possible

















Thanks to all who submit links!!!!
Last edited by Lee; Jun 01, 2015 at 11:06 AM.
Nov 08, 2008, 11:14 AM
Lee's Avatar
I love to fly this plane.

Last edited by Lee; Aug 26, 2009 at 05:47 PM.
Nov 08, 2008, 11:15 AM
Lee's Avatar
#5 Wing building and radio installation

Late note:

The following video shot in May of 09 shows several modifications that may influence the way you want to build your plane. The biggest of which is that the plane is being flown with no elevator but just the 2 wing servos used as elevons. This saves weight and flies great. Look at post 887 for more information

Peregrine with Elevons 5-09 (4 min 10 sec)
Last edited by Lee; Jun 06, 2009 at 08:12 AM.
Nov 08, 2008, 11:15 AM
Lee's Avatar
#6 Tail assembly and hinging
Last edited by Lee; Jan 05, 2009 at 04:17 PM.
Nov 08, 2008, 11:21 AM
Build it again, Sam!
Harpye's Avatar
Why not carving or milling the wings... would be that much easier!!! But is a great flyer!!!
Nov 08, 2008, 11:31 AM
Lee's Avatar
#8 Fuselage, motor and final setup.

We are always looking for a better way to do things. This post is being updated showing some possible some possible modifications you might want to consider. See post 887.

AUW - All Up Weight is 14.6 oz with paint and all radio ready to fly.
CG - The center of gravity is 1" back from the leading edge in the center of the wing.
Elevator goes +1" and -1" I recommend dual rate and/or exponential.
Ailerons also go +1" and -1" I recommend dual rate and/or exponential.

Many radios and motors will work. I am using the following:

Radio - Spektrum DX6i with 6100e receiver.
Servos - 3x HXT 900 from HC
Battery - 1320 3S Thunder power or equivalent
ESC - 20A+
Motors BP21 for speed or 1300 BW for long flights
Prop - 7x4 or 7x6 electric.

This plane flies well and has large surfaces to make it aerobatic and a lot of power with a BP21. It flies well with a BW1300 even at our 4600 foot elevation in Utah. I recommend decreasing throws with dual rates or exponential for people with less experience.

We have also learned one other trick on this plane is I launch it half throttle and then throttle up. I think it is due to the large control surfaces and low speed but it is easier to control using this method.

This plane is sensitive to the center of gravity. If it is off especially if it is tail heavy it is hard to control. Double check the CG before flying.

Last edited by Lee; Jun 25, 2009 at 09:05 AM.
Nov 08, 2008, 12:33 PM
Build it again, Sam!
Harpye's Avatar
Lee I have an idea but it is rather new tec and hard to construct and the more difficult to describe ....Stretch the wing cut out elements so the result is a zig zag structure afterwards push it together and glue it. If you take the elements in right angle / right sitze out, you are able to get a bent wing!!! Main problem is my bad knowledge of the English language - hope you rather understood what I tried to explain!
Nov 08, 2008, 01:25 PM
High Altitude Flyer
viking60's Avatar

The Soarbird Project

Lee & friends, here are a few photos of the various Soarbird design approaches.

Soarbird I & II were ~60" wingspan undercambered wings which flew OK in lighter winds, and glided decently. But when wind speeds increased, they began to be challenged.

Soarbird III was started as the answer to handling the higher wind speeds & moderate slope flying conditions... unfortunately I got sidetracked into other design projects, so it's yet to be completed. I expect it to perform well when finished, but it does use a larger hot-wire cut EPP wing.

Soarbird IV is the first 'proof-of-concept' prototype of a layered Bluecor Kline-Fogelman variant airfoiled wing. In early test flights, it displayed a need for more vertical stabilizer area, and would definitely benefit from being able to adjust the entire tailgroup's trim relative to the KF variant wing. Your technique of using a full-flying tailgrpoup seems like a great approach as the next modification on this prototype. So far, it's been flown only as a pure glider, but I can see myself building as second powered flight body. The full flying tailgroup change will be implemented when I get time to get back to some building.

Here's the web page:


here's the RCGroups SOARBIRD thread:


Nov 08, 2008, 01:29 PM
Registered User

Control surfaces?

Can you provide a bit more info about the setup:
Looks like the whole tail is set up to act as an elevator. I do not see a movable rudder, so is it safe to say that turns are accomplished with ailerons only?


btw, Peregrine sounds like a good name to me. Still a falcon, but distinguishable from all the other aircraft called Falcon.
Nov 08, 2008, 03:20 PM
Out the Window
High Flyin''s Avatar
Great looking airplane/bird. Much too fast for my abilities. I think Peregrine does sound good as the Peregrine is one of the faster falcons. If I remember right they exceed 200 MPH in a dive!

I need more of a slow buzzard for my reactions!

Nov 08, 2008, 04:07 PM
An itch?. Scratch build.
eflightray's Avatar
Just out of interest, the 'V' tail as 'ruddervators' works very well with a little dihedral. No need for a fin, (vertical stab).

I scratchbuilt a depron version of the EPP Eagle and love the way it flies, very realistic, at least enough to get attacked by the local buzzards.

Must admit to not seeing any birds doing rolls and loops, but the video certainly shows its speed.
Nov 08, 2008, 06:45 PM
Lee's Avatar
I took the EPP Peregrine out with the speed gun. The plane is slower than it feels. WOT it is only 45 mph. I am surprised it feels like it is doing 65+ from a flyer standpoint. It must be an illusion of the lightweight 12.3 oz AUW and the size of the plane. Considering the motor the speed is about what would be expected however.

I flew out 5 or 6 batteries on it today and that is saying something because this plane flies forever with a 1300 mA Lipo and that little 1300 BW (Blue Wonder) motor. My brain likes to fly it. The video doesn't do justice for what ir really looks like to see it in the air. It is well behaved and draws a crowd, even when it is painted like a seagull.

I let another experienced club flyer fly the plane and he says it feels like a high speed glass glider to him. Once again those planes are twice as fast as this is flying so I'm not the only one that is feeling the magic of the plane.
Nov 08, 2008, 06:58 PM
Lee's Avatar
Originally Posted by arniep
Can you provide a bit more info about the setup:
Looks like the whole tail is set up to act as an elevator. I do not see a movable rudder, so is it safe to say that turns are accomplished with ailerons only?


btw, Peregrine sounds like a good name to me. Still a falcon, but distinguishable from all the other aircraft called Falcon.

The Peregrine is flying with ailerons elevator and feels a lot like it is flying with elevons. The rudder is fixed and attached to the HUGE elevator. It does not have a movable rudder and it really doesn't need one. I don't like the way the rudder looks on the ground but it looks good in the air and makes the plane easier to see.


I have had several V-Tail planes and they are not anywhere near this responsive. If you look at the military Predator drone you will see the inverted V-tail. That set up actually tries to roll the plane the same direction as it is turning while the conventional V-tail rolls the plane out of the turn it is making. I'm actually surprised a V-tail works. We are contemplating the inverted V tail test on this plane.

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