Custer Channelwing: The
Facts
Too good to be true
???
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In this section, I will show you the facts, as I have found them. I know that I was a bit more than skeptical as I researched the channewing. To me, it was obviously, "too good to be true". As I uncovered more and more information, one thing was constant - everyone who has firsthand knowledge of the channelwing says, "yes, it works just as advertised". So that you might join the ranks of, "true believers", this section will contain only research data or pure verifiable facts, with the documentation to prove it. Obviously there is too much data on the channelwing to reproduce completely, but I hope to whet your appetite with the following figures and data. But, before you read this section, I will ask you to think of this exercise. Design a simple (not even flaps) five passenger plane with 450 HP, capable of slow flying at 20 mph, 160mph cruise, 200'' takeoff and landing, with extreme load carrying ability. If you can do it, you know more than any aeronautical department, or aircraft manufacturer, and I'd like to see the plans. On the other hand, the Custer CCW-5 did exceed all those parameters, and did it many years ago. Take a look! |
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| 1. | The custer channelwing is capable of vertical flight. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Because Custer had extreme difficulty in convincing aviation academics and manufacturers that the channelwing created a great deal of static lift, he concocted this demonstration. The CCW-2 was tied to a windsock standard on a calm day, and run up. As you can see, the aircraft levitated with the tie down rope parallel to the ground. It was lifted on the channel power alone. Even this did not convince the many skeptics. It was thought to be swinging on a pendulum, or some kind of trick. It was a classic case of NIH. (not invented here). They saw what they believed, not believed what they saw. This would help explain why Willard Custer had a tendency to lose his patience. |
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| 2. | The channelwing is capable of hauling very heavy loads. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Data recorded at Langley Aeronautical Laboratory, Langley field VA. and published in a 1953 NACA Research Memorandum RM L53A09. These tests were conducted at less than full power (2450 rpm) for reasons unknown, so they do not show full capability of the CCW-2 lift capability. Because the CCW-2 was a "tail dragger", the angle of attack while sitting on the ground was 20°. This gives 580 pounds lift and 635 pounds thrust on the channel. No channelwing ever built was configured for vertical flight, and consequently, on the CCW-2 the pilot had to hold back on the power until enough speed was gained to make the controls effective. Because of this, the CCW-2 required a ground run of 60 feet. Curly Custer did say that he flew the -2 without any form of aileron, and rolled with differential throttle. He also has pictures to back up this claim. |
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 I have heard that a modern flap system with leading edge flaps and slats coupled with trailing edge slotted flaps can generate a coefficient of lift of 5.5. But, I have never heard or even imagined a co-efficient of lift of 23! |
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| 3. | The unaided Custer channel is capable of generating 8.4 pounds static lift per horsepower. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| In 1944, the USAAF issued a technical report on the channelwing. The data was compiled in the 5 foot wind tunnel at Wright Field in Dayton, Ohio. The tests were on the CCW-1 and scale model channels driven by electric motors. remembering that the CCW-1 was the first real attempt at flying the channels and was in a rather embrionic state of development. It weighed 1375 pounds and was powered by two 75 HP engines. Even so, it was reported the channels lowered the takeoff speed to 36 mph from 51 mph if the the channels were replaced by normal wing sections. The experimental channel models, which were much better finished, showed 8.4 pounds lift per horsepower. For some reason, this was compared to a helicopter rather than other fixed wing aircraft. Helicopters of the time could generate 15.2 pounds of static lift per horsepower, so the conclusion was that the Custer channelwing was, "markedly inferior to the helicopter, but superior to other wing-propeller arrangements in producing both static lift and lift when forward velocity exists". Consequently, the final conclusion was, "The present device does not show sufficient promise of military value to justify further development by the Army Air Forces". An astounding conclusion! For instance, a channelwing fighter with the 1500 HP P-51 engine could develop 1500 X 8.4 = 12,600 pounds static vertical lift. The max TOGW for the Mustang was only 11,600 pounds. A bomber with four 1200 HP B-17 engines would have had 1200 X 4 X 8.4 = 40,320 pounds static vertical lift. Max TOGW for the B-17 was 65,500 pounds. A channelwing cargo plane with two 1200 HP C-47 engines would have developed 20,160 pounds static lift. The max. TOGW for the C-47 was 28,000 pounds. Admittedly, there are complications with using the Custer channel, but to say there would be no use to the military is beyond reason! At about this point, it is easy to sense the frustrations Mr. Custer must have felt. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| 4. | The augmented channel with deflector vanes generated 13.8 pounds lift per horsepower. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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The Custer channel with deflection vanes mounted behind the prop was measured to have a vertical lift capability of 13.8 pounds per horsepower. This was recorded in 1945 at Wright Patterson, and is documented in an AAF memorandum. It was noted that the channel and deflectors gave a considerable nose down pitching moment. This might change the design, but the extra lift would seem well worth the effort. |
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5. |
Cruise speeds are largely unaffected by the channels | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| The Custer channel is a wing when unpowered, and generates approximately 10% greater lift than a straight wing the diameter of the channel. This was verified by the L. H. Crook Laboratories report 557, in 1943. As speed increases, the coefficient of lift increases dramatically, as shown in the NACA report referenced in section 2 above. This allows less straight wing, hence less drag. This area has not been researched to a final conclusion, but it would seem logical that an aircraft with less wetted area would have equal or less drag. Harold Custer stated that at high speeds, the extreme downwash behind the channels did tend to push the nose down. To obtain high speeds without having to create negative lift on the elevator, it would appear that the prop / channel clearance would have to be changed in flight. Several fixes in this area have already been shown effective. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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6. |
The channelwing is cheaper to build and maintain than normal STOL. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| With modern methods and composites, the Custer channel is much easier to build than the normal STOL.This is because the Custer has no trailing or leading edge flaps and associated control systems. The CCW-5 and other plans from that era show the channel in the wing. This would be difficult and expensive. However, if the channel is placed in front of the wing, it is both simple and cheap. Notice the design for the P-20 Raider or the P-50 Devastator in the Dreams and Schemes section for an explanation. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 7. | The Custer is far cheaper to build and maintain than a helicopter. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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While a Custer has never been designed to hover, it would not be as difficult a task as it was to hover a helicopter. (my hat is off to mr. Sikorsky) If we were to build such a machine, it would have no moving parts, other than the prop, and flight controls. In effect, it would be a,"solid state", helicopter. Because of the simplicity, operating costs would be far lower, and utilization would be far higher. Added to this, would be speeds as much as double the speed of a helicopter. An example would be to replace the V-22 Osprey tilt rotors with Custer channels. Maximum takeoff gross weight for the Osprey is 47,500 pounds with two 6150 HP turbine engines. If we theorize we could match the 1944 tests, at 8.4 pounds static lift per horsepower, or the 1945 Wright Patterson tests that show 13.8 pounds static lift per horsepower, with augmented channels, the comparison would be:
(1)
USAAF Technical Report 5142 5 September 1942 Because of the higher cruise speed with the same engine, range would be increased 25% over the Osprey. In reality, because the Custer version would have far more lift from the wing, range would be even greater. Ferry range would be vastly improved, due to the ability of the Custer version to lift more fuel on takeoff. Notice the Custer version could lift an additional 22,656 pounds (1) or 55,866 pounds (2) of fuel or cargo.And remember, this is done without tilt engines, folding props, and the associated cost and maintenance.
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