Vintage a rules-

SUPPLIMENTARY RULES TO THE GENERAL RACING REGULATIONS –
CLASS VTR – VINTAGE “A” TEAM RACING MODEL AIRCRAFT
General - Vintage A team race is a nostalgia event based on pre-1957 Class A Team Racing. Characteristics of a Vintage A Team Race Model a) Model designs published up to and including December 1957 or commercial kits complying with the 1957 rules shall be used. The model must conform to the outline as shown on the original plan. Proof shall be provided by the contestant if required by the contest director. i) Models shall be of a scale or semi-scale appearance with a raised windshield ii) The model shall carry a realistic scale pilots head. iii) Wing aspect ratio shall be between 4:1 and 11:1. iv) Minimum effective wing area: 70 sq in. (452 sq cm.) [Note: This excludes the v) The minimum fuselage width at the cockpit shall be 1 1/2 " (38 mm). vi) The minimum fuselage height at the cockpit shall be 3" (76 mm). vii) The minimum wheel diameter shall be 1 1/2" (38mm) with a 1/16 inch d) Eligible Engines: The following engines are permitted for Vintage A: i) Pre-1957: Any engine that was commercially available may be used. ii) 1957 and later: Any commercially available plain bearing, non schneurle ported engine may be used. The following engines may also be used:- -PAW Single Ball Race (non schneurle ported) -Fora Pioneer 2.5cc (non schneurle ported) Modifications are permitted to any engine but must be in the spirit of the event. The components of a Vintage A engine should be equivalent to the design of the original components. Modifications which are carried out on these components are legal. Components or engines which are other than original origin must be equivalent in design to the permitted engines as listed taking into account the production variations of the period. Schneurle porting, AAC or ABC piston and cylinders or other configurations which differ in principle both materially and conceptually are not legal. Such items as the chroming of sleeves to reclaim worn engines and connecting rods of different cross section are considered to be within the spirit of the rules. i) Max. fuel tank capacity: 15 cc (Note: This includes all fuel lines and filters). ii) No multi-function or fast filling valves may be used, simple ball valves are accepted. iii) Refuelling shall be by squeeze bottle only. iv) Fuel shut-offs are optional but must not be used during the race. Each use will result in a 30 second penalty added to the race time. v) A Schraeder type valves are permitted. vi) Cox style needle and venturi systems are legal. vii) Shut offs may be used during the warm up period and only when the race has finished for f) Propellers: Only commercially available wood, nylon or glass filled nylon propellers may be used. Propeller modifications are permitted. g) Permitted Modifications: The following modifications may be made in the interests of i) The model may be strengthened, provided that the outline is not changed in any way. Only materials available in 1957 may be used in construction; however, modern adhesives may be used and metal motor mounts are allowed ii) The undercarriage legs may be extended, shortened or raked forward to promote safer handling on grass surfaces. Spreader bars are optional. iii) The fuel tank shape, venting and location may be changed to any suitable dimensions, and position in the model can be changed from that shown on the plan, that is, higher up, further inboard or outboard. iv) Air Inlet/Outlet and exhaust duct size and position can be changed from the original plan, provided the fuselage outline is not altered. The ducting of the air around the motor inside the cowl may be changed to allow correct operation of the motor. This means that the inlet, outlet and exhaust may be redirected. This may also mean some alteration to the shape of the cowl. v) Built up wings may be made of solid and aerofoil sections may be changed, for example, from flat bottom to symmetrical or asymmetrical or vice versa. Wing and tail planform outline must remain the same as original or within +/- 6.35mm of plan. Wing thickness may be changed; for example, 1/2 inch to 3/8 inch or 3/8 inch to 1/4 inch. vi) Internal leadouts are permitted even if not shown on plan. vii) Covering in fibreglass cloth is permitted. viii)The elevator position, size and number may be varied from the plan. a) Line Length: The length of the control lines must be 15.92m + 40 mm - 0 mm. The length is measured from the face of the grip on the control handle to the centre line of the model. b) Control lines: Two control line wires of a minimum diameter of 0.012" (0.3 mm) must be used. No internal line hook up allowed. c) Line Test: A pull test of 20 g shall be applied for 5 seconds to the model/line a) A contestant (pilot or mechanic) may compete in only one team in each event, unless otherwise permitted by the contest director. a) A contestant may use two models in any one event to complete the required number of heats/finals. Parts may be interchanged between the two models providing the resulting model conforms with all Vintage A rules. a) Races shall consist of two heats and a final. The three highest heat scores will go into the final. (A division 2 final for the fastest three teams with a time slower than 4:45 may be flown at the C.D's discretion). Heat distance will be 80 laps with one compulsory pit stop. Final distance will be 160 laps with two compulsory pit stops.

Source: http://www.afs.org.sg/afsorg/snac2013/Vintage%20A%20Rules-2013.pdf