RCPRO Quickie 25 - Rules

Airframe

a. Weight. Minimum 3-1/4 pounds, maximum 4-1/2 pounds.

b. Wings.

1) Area: Minimum 500 square inches.

2) Span: Minimum 50 inches (projected), maximum 52 inches (projected).

3) Chord: Constant for at least 47-1/2 inches of span.

4) Airfoil thickness: Minimum 1-3/16 inches for at least 47-1/2 inches of span.

c. Fuselage.

1) Depth: Minimum 3-1/2 inches at its deepest point, which must occur within the wing chord.

2) Width: Minimum 2-7/8 inches at its widest point, which must occur within the wing chord. Width and depth points need not coincide.

3) Cross-section: The fuselage shall have a simple, rectangular “box” cross-section with a maximum radius of 1/4 inch at the corners. Diamond-shaped cross sections are prohibited. Fillets or fairings between the fuselage and wing are prohibited. Canopies and turtle decks are acceptable but shall not be included in width or depth measurements. The front firewall shall be a rectangular, flat plate measuring at least 2-1/4 inches by 2-1/4 inches. The perimeter of the front firewall may be rounded to a maximum radius of 1/4 inch.

4) Engine installation: The engine and engine mount shall be fully exposed. No cowling or streamlining of the engine is permitted. A backplate-type radial engine mount that replaces the stock engine backplate may be used so long as it displaces the same crankcase volume as the stock backplate assembly. Corners and edges of the engine mount may be rounded to a maximum radius of 1/4 inch.

d. Landing Gear. The landing gear shall be fixed, with a least two main wheels of diameter not less than 2 ¼ inches. The main wheels shall be at least seven (7) inches apart, measured parallel to the wing span. No wheel pants, wheel spats, or strut fairings shall be used to streamline the main landing gear. Struts shall be either round wire, at least 1/8 inch in diameter, or any other material no more than 1/8 thick. Flat stock or molded gears may be filed or otherwise shaped to an airfoil cross-section. Nose or tail wheels, if used, may be streamlined or enclosed.

Engine

1) Maximum displacement: 0.250 cubic inch.

2) Configuration: Stock, commercially available, front-intake, side-exhaust.

3) Intake: A single carburetor, as supplied by the manufacturer of the engine being used, with a maximum inner diameter of 0.250 inch. The carburetor shall be fully functional and shall be stock, except for longevity-enhancing modifications as follows:

(a) Adjustment screws and idle needle valves may be held in place with commercially available thread locker, epoxy, or other adhesives and safetied with rubber bands, wire, or plastic ties.

(b) Barrel retaining screws or pins may be replaced with commercially available screws or pins of harder material and may be held in place with commercially available adhesives. Barrels may be deburred for smoother movement and may be safetied with rubber bands, wire, or plastic ties.

(c) Throttle arms may be modified or replaced.

4) Exhaust system: The engine shall be equipped with an expansion chamber muffler or zero-boost muffler as provided by the manufacturer of the engine being used, and having a single exhaust outlet with a maximum outlet area of 0.0621 square inches (equivalent to the area of a round hole measuring 9/32 inch in diameter). No modifications to the muffler are permitted except that the muffler may be tapped for a pressure fitting to supply pressure to the fuel system and steps may be taken to prevent the muffler from coming apart. The baffle must be used. Tuned mufflers and tuned pipes are prohibited.

5) Fuel feed: Other than muffler pressure, no fuel system pressurization is permitted.

6) Prior Approval: The O.S. 25FX, the O.S. 25AX, and the GMS .25 shall be the only approved engines for Quickie 25 until further notice. The engines and mufflers must be stock and unmodified except as specified above.

Propeller

1) Material: APC composite or a similar, commercially available composite.

2) Dimensions: Minimum diameter eight (8) inches.

3) Availability, modification: Propellers shall be commercially available. Propellers shall be stock, except as otherwise provided in paragraph 7.5.2.

From the AMA R/C Pylon Racing Rules:

7.5.2. In events requiring stock, commercially available propellers, the following modifications may be made without penalty:

a. One blade may be sanded on the top (front) side only for balancing.

b. One side of the hub may be sanded for balancing.

c. The shaft hole may be enlarged, but only as much as necessary to fit the engine crankshaft. The enlarged hole shall be concentric with the original hole.

d. Edges and tips may be sanded, but only as much as necessary to remove sharp molding flash.

Fuel

The fuel shall be commercially available, containing not more than 15 percent nitromethane, and shall be supplied and dispensed by the hosting organization. The dispensing operation shall include draining the tank of any existing fuel and then filling from a supply container when the pilot brings the aircraft to the ready box.