Wren 460, Peterson 260SE, King Katmai 182 - What are the design concerns of a 3 surface STOL Mod?

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Atlanta(ish), GA
I have been reading about the King Katmai for years, and I am fascinated by its performance characteristics.

Wikipedia for those unfamiliar with this mod.

Mainly, I love the idea of operating out of 500' and cruising over 150mph. The idea of a 3 surface STOL mod on an Experimental is really appealing, my mind keeps drifting to a Bede BD-4C with a canard modification, 140mph cruise, and the ability to operate out of 1000ft.

Most STOL designs on the market are STOL at all costs, but having something with STOL performance and cross country capability better describes my goal.

The trouble is there is a bit of a shortage of information on 3 surface airplanes. A few have been built: the King Katmai, Rutan's Catbird, the Commutercraft, Eagle 150B but I am having trouble finding information on the design and considerations of these planes.

What would it take to safely design a canard mod for an existing experimental, or is there an experimental that I have missed that does take advantage of this design with good results?
 

Pops

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Flew my Falconar F-12 off my neighbors farm for 2 years. 900' , one way in and one way out, turn final with no go-a-round. Cruise at 150 mph, with a 1700 FPM at GW and 2200 with just me.
 

blane.c

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I still say for stol it is the weird stuff like handles at various locations around the fuselage, the tail wheel is nearly always overlooked by those that don't realize the abuse it will take as it is frequently the first thing on the ground and the last thing off the ground and is drug through all manner of bushes, rocks, and what have you. Tires and gear and brakes are specialized as well. People have such a cockeyed idea about stol flying, unless of course they are talking about airshow circus acts but who give a hoot about that stuff really.
 
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An interesting video about the Eagle 150B, it touches a bit on the stall characteristics.


But, it also cites that is is a lifting tail, so I wonder how the downforce from the tail of the 182 effects handling.
 

Victor Bravo

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I believe the canard on the Katmai is primarily there to un-load the tail, which allows more of the tail to be used for pointing the wing up at a higher angle (instead of half of the tail power already being used up just to offset the pitching moment of the wing).

I believe that the main wing, with its flaps and STOL leading edge cuff are doing all the work keeping the airplane in the air.

Meaning that if you removed the STOL cuff and other high lift features from the main wing, I'm guessing the Katmai's big canard would not really make the 182 take off or land significantly slower/shorter.

Anyone who knows differently, feel free to correct me.
 

Mark Z

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The Wren was originally built in Fort Worth TX. I really know little about the history but my dear friend has a Cessna rigging business and is infatuated with the type. He probably knows more about these old modded birds than anyone. Look John Efinger up on Cessna Rigging .com. D4CBA8F8-1A68-4531-A83A-94D0981E2719.jpeg
 

Pops

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I have rigged many, many Cessnas. IF nothing is bent, going by Cessna's manual will do it. Huge percentage of flying Cessnas are out of rig. Makes a huge difference.
 

dog

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I believe the canard on the Katmai is primarily there to un-load the tail, which allows more of the tail to be used for pointing the wing up at a higher angle (instead of half of the tail power already being used up just to offset the pitching moment of the wing).

I believe that the main wing, with its flaps and STOL leading edge cuff are doing all the work keeping the airplane in the air.

Meaning that if you removed the STOL cuff and other high lift features from the main wing, I'm guessing the Katmai's big canard would not really make the 182 take off or land significantly slower/shorter.

Anyone who knows differently, feel free to correct me.
The canard operateration is linked to the elevator
and maybe also to the flaps,the system is patented.
The flight reports I have read all state that it is the ability to fly at low speeds coupled with a flat attitude and controlability that make the wren such
a legend.There is video of the system bieng operated on the ground,showing the differential control of the canard and elevator,one goes up the other goes down.
 

Victor Bravo

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Ahhh...so the Wren system not only unloads the elevator to counter the flap pitching, but it also puts an elevator on both ends of the airplane... clever !

Back in prehistoric neanderthal days of control line model airplanes, they had something they called "stunt flaps". When the elevator came up the wing flaps went down, and vice versa. It greatly reduced the diameter of the inside and outside loops you could do with the same model.

Stunt Flaps.jpg
 

Tom Nalevanko

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Cool P-40 model info... As concerns any patents, most probably long expired. The Peterson site has lots of info. I fly one of these (Cessna 182 with Peterson canard) and at slow speeds, the body angle stays relatively horizontal. Great for surveillance activities.
Best,
Tommy
 
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