Radio Control: Pylon Racing
Bill Hager
Well, as you read this, you will more than likely already know that the 1980 Nats will be held at Wilmington, Ohio—August 10 through August 17. Wilmington is located about 35 miles southeast of Dayton, Ohio. Dayton was the location of the 1976 Nats, which was one of the best attended Nats ever. Pylon had over eighty entries in both Quarter Midget and Formula I.
If all goes well, 1980 should be even better. Don't forget those of you who finish in the top ten in Formula I at the Nats are automatically qualified for the National Miniature Pylon Racing Association (NMPRA) Championship Race, provided that you are an NMPRA member before you race. This year's race will be held at Titusville, FL around the end of October. The exact date will be announced later.
I have been receiving a lot of mail showing what seems to be quite an increase in pylon activity around the country. I have also received quite a few requests to help in advertising contest dates. Sorry gang, but there just is not room to publish all of the dates in this column. I can only plug those contests of national importance. However, in order to keep people across the country informed as to what is going on, I will, from time to time, give some contest reports. If your area has a race that was reported, send me a write-up along with some 5 x 7 black-and-white photos and I will try to get it in.
It seems as though 1/2A pylon racing has become very popular. While most of us are watching the snowflakes fall, the .049 flier is still going at it. With a plane that small, you can just throw it in the car between races to warm up. I'm sure this has something to do with this type of racing going right on through the winter.
Some of you have written me asking what types of rules are being used for 1/2A. Here is a set of rules used in the Wisconsin area:
Stock Engines
Generally, the engine must be used "as is" from out of the box, and any replacement parts must be used "as is" from the original manufacturer. Any replacement parts from other manufacturers must be equivalent to the original factory parts; that is, they must not be designed for increased power. Violations of the stock engine requirement include, but are not limited to:
- Increasing the venturi bore.
- Increasing the size of the cylinder bypass ports or exhaust ports or compression ratio.
- Changing the shaft port timing.
General
All AMA and FCC regulations covering the RC flier, his aircraft, and equipment shall be applicable to this event except as noted herein. There shall be no limitations on the type of radio equipment fitted to the aircraft except that only two control functions shall be actuated; e.g., elevator and ailerons, or elevator and rudder.
- Each contestant shall be allowed to enter two aircraft. The second aircraft may be used only as an alternate and does not constitute a separate entry.
- Parts from one aircraft may be used as parts for the other aircraft.
Aircraft Requirements
The following aircraft configurations are not allowed: flying wing designs, pod-and-boom designs.
All aircraft shall meet the following measurements:
- The perimeter/girth of the fuselage measured at a point midway between the rear of the wing and the front of the stabilizer shall be 3 in.
- Any concavity of the aircraft sides measured by laying a straightedge along the fuselage side shall be no more than 1/8 in.
Aircraft Specifications
#### Engine
- Maximum total nominal engine displacement shall be 0.0519 cu. in.
- Engines must be stock production units assembled from stock parts.
- Engine and all parts, whether original or replacement, must have been produced in quantities greater than 1,000 units and must be available through normal retail outlets in the U.S.A. or from the engine manufacturer.
- No ball-bearing engines or tuned exhaust systems are allowed.
- No throttle or muffler is required.
- Kim-Kraft needle valve assemblies are allowed.
- The use of cylinder heads modified to change the compression ratio from that of a stock engine is not allowed.
- No fuel pressurization except atmospheric pressure is allowed.
- No screen is required on the venturi.
- Lapping and fitting of engine piston and cylinder is permitted; however, no grinding, machining, or filing of engine parts is permitted.
- The venturi diameter shall be no larger than 3/16 in.
#### Propellers Either wooden or plastic two-bladed fixed-pitch propellers are allowed. Spinners and propeller reworking are allowed.
#### Weight Weight less fuel but including all equipment necessary for flight shall be at least 20 oz, but not more than 32 oz.
#### Fuselage
- The fuselage shall have a minimum width of 2 in. and a minimum height of 4 in. Both measurements need not occur at the same cross section; both measurements must occur within the length of the fuselage bounded by the wing chord.
- Fillets, profile canopies, profile cowlings and other profile extensions shall be counted toward meeting the minimum width and minimum height measurements.
- The minimum width and height requirements are waived if the fuselage has a minimum cross-sectional area of 8.0 sq. in. If challenged by contest officials, the contestant shall provide documentation that his aircraft fills this requirement.
- No landing gear is required.
- That part of the wing which is intersected by the fuselage shall be considered as part of the fuselage when determining fuselage height.
- An extension from the basic fuselage is a profile extension if, at its base, it is less than 1 in. wide.
#### Fuel
- Fuel shall contain 25% nitromethane and shall be provided and dispensed by the contest sponsors.
- Fuel tank capacity is limited to 2 fl. oz.
- Fixed fuel pick-up line or other positive fuel cut-off is required.
#### Wing
- The minimum wing area, including that part intersected with the fuselage, shall be 200 sq. in.
- The wing shall be of constant chord and shall have a minimum thickness of 0.875 in.
- Any portion of the wing that does not conform to the constant-chord planform or does not meet the minimum thickness requirement shall not count toward meeting the minimum wing area requirement.
- For identification purposes, the right wing shall have affixed two large numerals—readily visible.
This is just one example of 1/2A rules in one area. Your area may be different, so check with the local fliers before you start building.
See you next month.
Bill Hager 4622 Bridgeport Dr., Garland, TX 75043.
Transcribed from original scans by AI. Minor OCR errors may remain.
