5.3.2 FORMULA 400 PYLON RULES (F400): As Amended for VMPRA sanctioned events. Effective date 1st January 2011.
18.104.22.168 Definition of Radio Control Pylon Racing Model Aircraft:
A Radio controlled pylon racing Model Aircraft is an aircraft in which the propulsion energy is provided by a piston type engine – the lift is obtained by aerodynamic forces acting on the supporting surfaces which, except for control areas, must remain fixed in flight. The Model Aircraft must be of a semi-scale type and their general lines must be in accordance with those of full-size aircraft. Competitors may be required to justify any unusual or unconventional features of their Model Aircraft design, with documentary evidence of similar full size aircraft.
Definition of commercially available:
An engine or part (parts include any item used for competing in the specific event) is commercially available if;
a. An identical engine or part can be obtained within a reasonable time by any consumer at a price that is independent of who the customer is; and
b. If an engine or part was once legal it is always legal, with one exception. The exception is if this engine or part is specifically made illegal by another rule;
c. the following information is disseminated by means of a catalogue, an advertisement or reasonably calculated to bring it to the attention of RC pylon racing contestants:
1) Catalogue number or other specific identification;
2) Price; and
3) Name and telephone number of the manufacturer or other source.
The engine must be a two – stroke cycle, glow ignition of the reciprocating type, be commercially available and have a maximum swept volume 6.6cc. The engine must be of front induction – side exhaust configuration.
Modifications to engines and parts are not permitted. The “engine” is defined as the complete unit, ready to run. Must use parts made by the engine manufacturer needing only propeller, fuel, and starting voltage. The following parts may be substituted for the original parts and may come from any source;
- Backplate mount
- Glow plug
- Head and crankcase bolts
- Propeller nut
- Propeller washer
- Remote needle valve assembly
- Shutoff mechanism
- Venturi maximum internal diameter is 9mm or 64 sq mm (in case the venturi is not round)
- Oversize muffler bolts
- Spinner cones may be substituted with hub type propellers
22.214.171.124 Shut – Off:
The engine must be equipped with a positive radio-controlled shut off. The pilot shall be able to shut off his engine by radio control on the ground or in the air.
Pressurized fuel tanks are permitted. (Viz. Crankcase or muffler pressure)
The engine shall be fitted with a silencer or tuned muffler as provided by the original manufacturer for the engine being used; within the general length there shall be an expansion chamber not less than 45mm outside diameter, with a maximum length of 184mm. The silencer shall have a single orifice with a maximum outlet diameter of 7.2mm
Modifications to mufflers are not permitted but may be repaired.
Tuned pipes are not permitted.
Only fixed pitch propellers shall be used. Two-bladed composite resin continuous fibre construction or APC injection molded propellers with part numbers in the family LP07XXXC, where “X” signifies the three numbers indicating diameter and pitch may be used. APC propellers shall be stock, except for balancing.
Balancing of APC propeller –
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.
A rounded nose spinner nut with at least a 4.5mm radius on the front is required.
Cross Section - The fuselage shall have a minimum height of 127 mm and a minimum width of 75 mm, the measurements to be of the fuselage body and are to exclude any fins, attachments or spacers. Both minimum dimensions must occur at the same cross-section location. The fuselage will have a minimum cross- sectional area of 80.6 cm2, excluding fillets. Competitors will be required to provide templates to prove this. Fillets are not considered part of the fuselage or lifting surfaces.
126.96.36.199. Landing Gear:
At least two wheels shall be used with a minimum diameter of 50mm. The two main wheels must be a minimum lateral distance of 15cm, when the Model Aircraft is at rest on the ground. A retracting undercarriage is permissible.
188.8.131.52. Lifting Surfaces:
Area The total area of the wing shall be a minimum of 2550cm2. On biplanes with different wings, the smaller wing shall be at least two thirds of the larger wing. Flying wings and deltas will not be allowed in this event.
184.108.40.206. Wing Thickness:
The depth of the wing must be a minimum of 22mm at the root of the root cord of a monoplane, and 17 mm if a biplane. On a biplane with wings of a different size, the smaller wing must be at least 15mm thick at the root.
If the wing is not uniform in thickness, then the thickness must decrease in a straight line from root to tip as viewed from the leading or trailing edge.
Note: “Root” is defined as the innermost wing section, excluding fillets that may be measured without removing the wing from the fuselage. On a completely exposed wing, much as that of a parasol monoplane or the top wing of most biplanes, the root is that section of the wing that is intersected by a projection of the outline of the fuselage as seen in the top view, i.e. The root section would be 50mm from the centre line of an exposed wing on a Model Aircraft with a 100mm wide fuselage.
The minimum weight of an assembled aircraft, ready for flight, but less fuel shall be 1.8kg.
The organizers shall supply fuel to a standard formula for glow plug motors. Its composition shall be 80% methanol, 20% castor oil.
220.127.116.11. F400 Course Layout:
The F400 course will be the same as the FA1 pylon course, refer to rule 18.104.22.168
22.214.171.124. CD’s option.
At any time, the CD or the CD’s designee may inspect an engine or aircraft entered in the contest.