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| Home :: Ask the Team |
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August 2010
From Thunderscreech84: Hello, I am such a huge fan of what you guys are all doing. I was looking at your web site and was wondering if Wildfire would be at Reno this year? I hope so! I think the plane looks awesome and I think you guys are doing a great job with the resources you have. Thanks! Thunderscreech84, Thanks for being a huge fan of the Wildfire project. Unfortunately, we will not be at Reno this year. We are making some big changes to the racer, such as new engine cowling, going back to the four bladed prop and a new test pilot. Then on to finishing the flight test program. We are finally getting the web site updated. Should be ready by the first of September. Check it out. Bill Jr. August 13, 2004 Bill: Allen, August 25, 2004 Bill Statler Jr. Hey Bill! I would be honored. You certainly have my permission. The engine cowling is very unaerodynamic looking and also ungainly/unattractive in all of the photos and your big illustration and the prop spinner is way too small for good aerodynamics. Will these be made any more attractive and less drag inducing before it shows up at Reno? What about strakes/ streamlining at the wing roots? I saw the 3 view drawing in Sport Aviation a long time ago and except for the dainty prop spinner this looks "Right" and much slicker to me. Be interesting to see an update, and thanks. Thanks for your interest in the Wildfire project. Meaning no disrespect to your dad, "If it looks good it'll fly good" is one of the oldest wives tales in aviation. Looking good has very little to do with aircraft performance. The Gee Bee was one of the most unstable aircraft ever designed due to it being so short coupled and its' inadequately sized control surfaces. As to the status of the project, it's moving along quite well. Everyone working on the project is a volunteer who has a regular 40 hour a week job, so naturally, we can't spend as much time working on the project as we would like to. The last system installation to be completed is the new fire suppression system sponsored by HRD Aero Systems. All components are installed with only the plumbing remaining. Once this is completed we can start with the functional checks on the fuel, oil cooling and hydraulic systems. The new wing fillets are under construction leaving the gear doors as the last construction project since they are not required to initiate the flight test program. You have to remember that this project was built for only one reason. To fly fast around a pylon race course. Therefore, everything you see on this aircraft is there for a purpose. In order for the P&W R2800 to perform at it's best it needs the proper air flow into the carburetor and the proper cooling of the cylinders. Your "very un-aerodynamic looking and also ungainly/unattractive" opinion of our engine cowling is just the opposite opinion of our Crew Chief and the two other gentlemen that built up our racing R2800 engine. These three gentlemen are probably three of the best R2800 mechanics in the country, if not the world. When they saw what we had done to insure the engine would get the air it needed by means of the big scoop on top of the cowling, they could not have been happier. Their comment was "someone finally got it right". The scoop design creates very little drag, if any. As for our spinner which you feel is "dainty and way too small for good aerodynamics" just the opposite is true. Our current spinner came from a DC-6 which used four R2800 engines and cruised at 315 mph with a max speed of 400 mph. During it's reign as a passenger airliner, these were pretty good numbers. The spinner you see in the pictures is identical to the one we have now but the one in the pictures came from a DC-7 which had four bladed propellers. We are now using a three bladed propeller since it is more efficient than a four bladed prop at high speeds. This narrow pointed spinner is referred to as a "high speed" spinner. As I mentioned earlier, two things (regarding air flow) are required to allow the R2800 to operate at maximum efficiency. I've mentioned adequate air into the carburetor, the other is proper cooling of the cylinders on the engine. The cylinders on a P&W R2800 are 14 1/4" high from mounting base to the crest of the valve cover and have 'cooling fins' in most of this area. These cooling fins need air flow to keep the cylinders, thus the engine, at the proper operating temperatures. Just like any other internal combustion engine, if it operates at temperatures that are too high it's losing power and running the risk of sustaining severe engine damage. Our spinner is not only aerodynamic it also allows the proper air flow into the front of the engine for adequate cooling of the cylinders. There is an adage which does apply here though that one needs to pay close attention to. "What goes in must come out". You need to be sure that all the cooling air coming in the front of the cowling for cooling has an exit at the back of the cowling. If it doesn't, it will try to exit back out the front of the cowling and this will create a lot of unwanted drag. A lot of the other Unlimited Class race planes that use the 'round' engines are using the large diameter spinners that reduce the distance from the cowling to the spinner down to 2"-3". Now these might look cool and aerodynamic to the viewer, but do the simple math. If we were to limit the cooling air to only the top two or three inches of our cylinders, we have reduced the cooling capabilities of the engine by 80%. Regarding your question about using strakes. Strakes are used on supersonic aircraft only. They usually run from the fuselage to the leading edge of the wing and produce additional lift at high speeds. Strakes really do not produce any lift at low speeds and are not used on subsonic aircraft. There is no application for them on our type of aircraft. As I mentioned earlier, we are in the process of manufacturing new more aerodynamic wing fairings, or fillets. The ones you see in the pictures were installed quickly on a temporary basis so that we could start our test flight program earlier in the program. Hope I have answered your questions Bill. Thanks again for your interest in our project!
Growing Pains? Glad to hear you're interested in the Wildfire project and I will be glad to answer your questions. Your first question: The aircraft has been sitting in a hangar at the Mojave airport, not Van Nuys. The aircraft received only minor damage to the blade tips and after the tips were dressed, or cleaned up, work on the project continued. The incident you refer to with Skip Holm at the controls was caused by an error on my part for which I take the full blame for. The pilot who flew the first test flight for us insisted that we put 200 lbs of ballast in the tail. This should have been the red flag that told us this guy was not a test pilot as he claimed, but we missed it. Before Skip did the taxi test I told the crew to remove the ballast from the tail, meaning the extra ballast the first pilot insisted we install. The crew misunderstood what I meant and removed ALL of the ballast from the tail. I didn't make it clear what I meant. My fault. Without the ballast in the tail, the light racer pushes the forward cg limit with the R-2800 mounted on the nose. When Skip hit the brakes, the tail came up just enough to tic the blade tips. It was not long after this that the money ran out so we had to hangar the project. Lack of funding was the reason Wildfire remained in the hangar for almost twenty years, not because of the incident with Skip Holm. Secondly: The wing we are using is most definitely not a clipped T-6 wing. We are using a completely new wing that we built from scratch using a NASA airfoil designed for speed which will maintain lift in the turns on a pylon course. Your third question: We hope to begin the flight test program this spring. We are currently installing the last system in the aircraft. This is a sophisticated fire suppression system donated to the project by HRD, a company in Valencia, Calif., that provides oxygen and fire suppression systems for commercial and private aircraft. After this is done, we'll make the new high speed wing fairings to replace the temporary fairings we installed for the first test flight. Hopefully we'll have all of this done for the spring flight test program.
T-6 or not T-6? We did not mount an R-2800 on the front of a T-6. To do so would be foolish indeed. The old T-6, as rugged as she is,
The forward tubular section of the T-6 was used but was totally rebuilt and strenthened in order to handle the power of the Pratt &Whitney R-2800. The wings, fuselage and the empennage are all new designs and built from scratch. Wildfire was designed and built to be a pylon air racer and, therefore, uses technology which will give it an advantage in pylon racing. Wildfire will be as fast as you stated in your article. We won't know the top speeds it could reach until we are well into our flight test program. Will Wildfire be the Unlimited Champion when it gets to Reno? We'll have to wait and see. Dago Red and the Rare Bear are the ultimate in Unlimited Class air racers. Their crews and owners deserve a huge "Well Done" for what they have been able to accomplish with 60 year old WWII fighters. It will be our honor and thrill just to be in the Championship race with them no matter the outcome and if we help to promote air racing in the process, then we will have accomplished what we set out to do 25 years ago.
Engine choice Keep up the good work at the University of North Dakota. Commercial Aviation is an excellent field to get into. It will always be a necessary part of our lives and it constantly needs young people like you to come up with new ideas to make it user friendly and profitable. I also hope that Air Racing some day can be as big as NASCAR. The problem air racing has of course is the lack of races during the year. As you know, Reno is the only game in town at the moment. The reason there aren't more air races is
To answer your question. There were a couple of key reasons we picked the R-2800 over the R-3350 and R-4360. The main reason of course was the weight factor. The R-2800 weighs about 2600 lbs where the 3350 weighs in at about 3000 lbs and the 4360 is nearing 4000 lbs.. The R-2800 is a strong, reliable engine with few maintenance problems if treated right. In order to go faster than the others, you have to be lighter than the others for starters, ergo, the Pratt &Whitney R-2800. By the way, the R-4360 is a mechanics nightmare. The 4th row of cylinders is always over heating and since you have two magnetos for each row of cylinders, keeping eight magnetos timed and in sync gave the mechanics a real headache. A good friend of mine was a mechanic on the 4360s and I got this straight from him. Hope that answers your question. If you ever get to Reno when Wildfire is racing, please come up and introduce yourself. Be glad to meet you.
I am curious about your prop, is it stock from say a DC-6? Are the hub and prop original mates? For example on my plane we have a corsair hub and Connie blades for a four-blade combo. Looking at your pictures, it is obvious you have done a lot of mods and really beefed up the tubular structure of the original design and your work looks impeccable. How many gallons will your ADI tank be? I carry 17 gals. I use de-minerized water or even distilled, and a dash of Chevron "b" or water-soluble oil with no parafins, and lastly all 666 Teflon lined stainless hoses and stainless fittings throughout the ADI system. This keeps my fuel feed valve clean and operational and minimizes corrosion and particulates in the ADI system. I use it about every other take off and I don't baby the engines with reduced power takeoffs which means I can go to 57.5" on T/O. I wish I could run 115/145 that would be a treat but I am in awe of the power of the engines when I make a wet T/O. Currently I am finishing a 3 yr full-time 40-50 hrs/wk restore of an HU 16B and have done 2 other large plane restorations, so I can appreciate the amount of work you have put into this project. Too bad I didn't know you existed as I was just on a trip out your way last month and we overnighted at Skytrails on the south end of Van Nuys with our Howard 500. Pull us aside next time we come in there I'd love to see your project. Good luck, great job, beautiful ship!! Ask the Team a question at StatlerAir@AOL.com and we'll show selected questions here.
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