1. PURPOSE: To provide an affordable, basic and simple traditional control-line speed event that any modeler of reasonable ability can build and fly. The event is a simplified version of .21 Proto but allowing a profile fuselage and a standard low-tech engine. The use of one engine choice is designed to provide close competition in a reliable and inexpensive manner at speeds somewhat comparable to the glory days of Proto Speed in the 1950s.

2. All current applicable Academy of Model Aeronautics Speed rules shall apply, except as follows:

3. AIRPLANE: Minimum 125-square-inch wing with a minimum 20% stabilizer. Rudder must be a minimum of 5% of the wing area and mounted in the traditional upright position. Use of a subrudder is prohibited. Model may use either a full fuselage design or a profile. Fixed two-wheel landing gear with minimum 1-1/2-inch diameter wheels laterally spaced at least 6 inches apart. Model must have a canopy with minimum dimensions of 1 inch high by 3-1/2 inches long. Canopy may be clear plastic or painted on. The engine can be mounted in any position. Cowling of the engine is optional. Entrants’ MAAC or AMA license number must be displayed on the upper right hand wing panel with a minimum 1-inch height.

4. ENGINE: The event will use a standard OS .25 LA engine. There is no restriction regarding engine modification, except that all major components shall be from the original manufacturer specifically for that engine.  Engine parts such as venturi, needle valve system, screws, prop washers, gaskets, etc., may be from any source. Use of the muffler is optional.  Only two-bladed propellors may be used.

5. LINES: Minimum length as measured from center line of handle grip to the fuselage centerline is 60 feet.  Only single strand lines may be used.  Two-wire control systems shall have a minimum line diameter of .014 inch, and single-wire control systems shall have a minimum line diameter of .024 inch.

6. PULL TEST: The model and control system shall be subjected to a 24g pull test.

7. TIMING: Timed from takeoff to 14 laps, (1 mile),  standard Proto Speed timing


Northwest rules are coordinated and sponsored by Flying Lines the independent voice of Northwest control-line model aviation. Suggested donation is $5 per year. Donate via the You Can Help page or mailing to:

Flying Lines
2456 Quince St.
Eugene, OR 97404

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