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.

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.

16.3.1. Airframe. The airframe specifications for this event are identical to those for Quickie 500 (Event No. 428) with the following exceptions: Wing and tail construction. Wings and tails must be constructed of either all wood or wood sheeting over a solid foam core. Wings and tails manufactured in molds designed to produce hollow core structures are prohibited. Traditional fiberglass reinforcement, carbon fiber or inset wood spars continue to be acceptable. The last three inches of each wingtip may be made of any material. The intent of the rule is to keep the cost of participation to a minimum.