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have to get around Dreadnought if you want to win Reno.
That isn’t as easy as it sounds, and few racing planes have done it on a consistent basis. If perennial favorites like Strega, Dago Red (right) and Rare Bear are running well, they’ll be out in front. Mike Brown will be there, too, in September Fury. Tom Dwelle and Critical Mass have done it, and finished third last year; his best finish ever. They have the horsepower and speed to win.
But you’ve got to get around Dreadnought.
Sea Furies have been raced at Reno and various other events for a long time. Mike Carroll, and later Sherm Cooper, raced the gorgeous Miss Merced (left) beginning in 1965. Ormond Haydon-Baille raced his stock Fury in 1971, and Lloyd Hamilton raced not only his stock Fury, but also came up with a racing version. There were a handful of others, too. With the stock Centarus engine, the British fighter would never be a top unlimited contender, but it ran well in the cross country competitions.
So... What if the airframe got big horsepower? What would happen then? The wing was already an excellent choice for a fast race plane, and the airframe was sized for carrying enough consumables. If a larger engine was going to be used, the increased fuel consumption, ADI and water flow rates would mean a lot of liquid would have to be carried.
The idea originally came from Bill Kerchenfaut (left) and the late Sherman Cooper back in the 1970s. They ran the yellow and flame draped Fury around the pylons with a degree of success until an engine failure forced the plane into a desert belly landing. They had an idea that a R-4360 would look good on the front of a Sea Fury, and that the result would go like stink.
Time went by, but nothing was ever done. Cooper would be killed in an accident, and Miss Merced was sold. Bill Kerchenfaut would go on to be crew chief on a number of successful racers. Nobody would fulfill the Sea Fury/R-4360 prophecy.
Enter The Chino Kids. In 1982, they were making an F2G Super Corsair (right) racer out of an old F4U-1 they had in their yard. A massive R-4360 was bolted onto a custom engine mount, a Skyraider prop was installed, and flight tests began. Frank Sanders flew chase in his stock two-seat Sea Fury (below) during a test flight out of Chino prior to Reno. Jim Maloney, at the controls of the Super Corsair, put power to the engine for the first time during that flight.
The 4,000 hp. racing Corsair pulled away from the stock Sea Fury like it was tied to a post. Sanders, from his cockpit, watched as the Super Corsair marched away at a dry power setting of 50 inches and 2,800 rpm. Years later, Frank’s son Brian would recall his dad’s impression. "My dad said, with all due respect, ‘If that big, draggy piece of shit will do that, think what a new, cleaner airframe like a Sea Fury would do!’"
Exactly. Sanders huddled with his sons Dennis and Brian... "You want to go air racing?" Brian thought at the time, "We had nothing better to do..."
But first, Sanders (right, with wife Ruth) had to know if the airframe could even handle that type of horsepower. Engineer Bruce Boland, of Lockheed and air racing fame, was brought in to do the load calculations, taking into account horsepower, gyroscopic, and G loads the engine would generate. "Stout for hell," was his reply. Green light.
If You Build It, You Will Win
The racer that would become Dreadnought traces its lines back to two separate airframes. The first was a two-seat German Air Force target tug registered D-COCO. It was imported to the United States in 1977 by John Stokes. One year later, the plane was sold to Bill Harrison, who raced it in 1978 as Wasa Hooker. Shortly after the races, Robert Friedman acquired the aircraft, but was killed in it during a takeoff accident two weeks after he bought it.
Sanders had bought the wreck in 1979, as well as another two-seat Fury airframe from Rangoon. Sanders told the seller if he could get the plane to California, he would buy it. Low and behold, the airframe arrived in California and the deal was made. The initial idea was to build up a trainer from the airframes for sons Brian and Dennis. That idea went out the window when the Super Corsair walked away from Frank’s Sea Fury.
Brian (left), now an accomplished warbird and race pilot, picks up the story.
"When that plane was delivered to us back in ‘78 or ‘79, there was a good six inches of rat turd in the bottom of it. Rats and mice had also scurried up the exhaust pipes and ruined the inside of the engine and its unique sleeve valves. Those are the hardest parts to find these days." It must have been a sorry sight, but the racer’s day would come.
Right after Reno 1982, the Sanders family got to work on their masterpiece. Sanders explained, "We sold our AT-11 and took the money and bought -4360's from Davis Monthan, some radios and such, and reinvested it in Dreadnought. It was a hell of a lot of work." Part and components from the two airframes were combined into one. "We worked on it from October straight through to Reno. It was always a mad thrash," Brian said.
Frank always had strong ideas about engineering a part or a structure, but no background to back it up. His crew included his sons, one full time worker and several part time volunteers. Bob Smith, a head aerodynamicist at Douglas Aircraft, was introduced to Sanders via a car racing connection. Obviously, a man with this background would bring a wealth of experience to the program. He did the cooling calculations for Dreadnought (left, in 1983), and found out they had just enough flow through the cowling to keep the cylinder head temps just below the red line. Since heat makes horsepower, this was optimum. He also verified the inlet and outlet areas for the oil coolers.
"He’d laugh at my dad," Brian said, "Dad would design something and have Smith look at it and verify it. Everything firewall forward had to be done from scratch... The induction inlet shape and the cross section, taking into account airflow constriction and diffusion, speed, and pressure..." The engine mount, spinner, cowling and intake and exhaust pipes were all custom built for the racer.
With a good portion of the airframe work done, the racer was put on jacks, leveled perfectly with a transit, and plumb bobbed both front and rear to provide an accurate centerline. The huge radial engine was put on an adjustable wheeled cart and rolled up next to the firewall. They plumb bobbed the engine and squared it perfectly with the airframe, and began to make measurements.
A KC-97 engine mount ring was the first piece to be worked on; all of the stock attach points were removed, and new points were built. Tubing would mate the attach ring to the firewall.
"Typical of our dad..," Sanders mused, "When we were cutting the tubes to connect the engine attach ring to the airframe, he built a set of tubes out of muffler moly - real thin steel that is easy to work with. He sat down, measured and cut all the shapes out of the thin steel. Then he bought aluminum tubing and put that over the steel and marked it all to cut. Then we slid that over the 4130 tubing, marked that, and cut that. So, we now have a complete set of patterns if we ever want to build another mount for a -4360."
With Reno on the horizon, the airplane was completed and test flown. The hulking racer was nothing like the sleek racing Mustangs or the compact Bearcat. It was huge. Typical of British nautical terminology, the racer was christened Dreadnought, and finished in a silver and red prototype scheme. She was assigned race number 8, and was registered N20SF once again. (ES.9505/VZ350).
Flight Test - Got Stability?
Test flying showed two things. First, it was fast. It was also unstable The R-4360 is a much longer engine that the stock Bristol Centarus. Even though the engine was moved back to within a half-inch of the firewall, the prop line was still 10.5 inches farther forward that a stock Sea Fury. This is a destabilizing effect on any airplane. Since a four blade Skyraider unit was being used, the additional 2.5 square feet of prop area would also add to the problem.
"There were stability problems," Brian said. But there were fixes for Dreadnought. "One time dad and I were out working on the stability problem. He took the airplane and yawed it about 10 degrees, and let go of the rudder. Normal airplanes would yaw back, but Dreadnought would stay yawed at 10 degrees. It would fly along sideways perfectly happy."
While testing over the Chino airport one day, both Frank and Brian got a huge wake-up call. "Dad locked his feet on the rudder pedals so they couldn’t move; this was for a gyroscopic test of the propeller. He banked over into a turn and pulled three G’s, and it started to swap ends," Brian said. "The thing yawed 15 degrees nose right, and the tail stalled. You could feel the shudder as the vertical fin started to stall. Dad jumped on the left rudder, it came back straight, and he said that was enough! We were only at 6,000 ft. That wouldn’t have been pretty... tumbling Dreadnought down over the airport."
Bob Smith, with a lifetime of aeronautical achievement, shot down some band-aid ideas and told the Sanders to lengthen the vertical tail by a foot. The end result was a fixed portion of fin over the moveable rudder and two additional square feet of area.
"Before we made it permanent," Brian said, "We did a scab-on with pop rivets and sheet metal. Dad went out and flew it gingerly because this wasn’t structural. I went out and I flew it, and so did Dennis (right). It flew good. Then Lloyd Hamilton came down. He had already flown his R-4360 powered Furias that first year, and knew there were stability problems. Dad told Lloyd to go out and fly it, and he came back and said it flew really great. He had yawed 10 degrees and all of this. Dad was pretty surprised something didn’t rip off. ‘It’s just pop riveted on,’ Dad said. ‘You were lucky you didn’t tear it off!.’"
Mild Mannered, So to Speak
With the heavier engine up front, the oil tank had to be relocated aft of the rear seat. Other changes were made to the tankage in the wings for the fuel, ADI and spraybar water. Hundreds of small changes were made throughout the aircraft; the canopies were refined, full dual controls were installed, and better brakes were put in. Overall, the racer proved to be consistently fast, and its stability problems were overcome to the point where it’s mild-mannered compared to some other race planes.
One of the final issues centered on the Aeroproducts propeller that was being used. Dreadnought was equipped with an early Skyraider prop with M-20 blades. These were hollow blades that had the structure built into the rear half. The front half was brazed on and featured a two inch flap at the trailing edge. The idea was more blade area meant more thrust, therefore more speed.
Frank had heard about similar H-20 blades; they have less area and no trailing edge flange like the M-20 blades. A set was found and installed on Dreadnought. "We did a bunch of flight testing for the 1985 races. We found them to be 2 mph faster," Brian said. "That may not seem like a lot, but at the top end, even one mph is hard to come by."
One change lead to others, and more refinement. "When we ran that prop, we had some prop buzz, which you just don’t hear at that gear ratio and that speed on the Sea Fury," he said. "We went to Bob Smith about it, and he said the tips of the prop needed to be unloaded. We were running more pitch, so we needed to load the middle of the prop and unload the tip. We took a wide chord propeller, left it at full width in the middle, and trimmed the flange as we went outward. There is no flange at the tip. If you look at Dreadnought now, you’ll see that the prop has more of an elliptical shape on the trailing edge. We also got rid of the cuff at the root. The leading edge is still stock."
Story by Scott Germain - WarbirdAeroPress.com. Copyright 2004. All Rights Reserved. Thanks to Brian Sanders and the entire Sanders family. Technical drawing courtesy of Taichiro Yamashita. Photo of Frank Sanders via Pete Law. Miss Merced Photo by Emil Strasser.
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