Control Line Speed Rules and Model Classes

The complete official set of AMA Control Line Speed Rules is available at the AMA website (under the Competitions&Events – Rules link – 2015 – electronic timing legal for AMA classes).

For the FAI Speed rules please refer to the FAI website, section CIAM – Sporting Code – F2 Control Line

Besides these official disciplines, contests in North America are held in

C Speed                                            Provisional C Speed Rules

Sport Jet                                         NASS Sport Jet Rules (rev. 2/16/2015)

Vintage Speed                              NASS Vintage Speed Rules

Perky Speed                                  NASS Perky Rules

Below we present a brief of the speed model classes, just click on the model image to get to the appropriate section

speed model classes

Submitted by Lloyd Burkett


1/2A Profile Proto                                                                           Engine size 0.05 c.i.

1/2A Profile is intended to be an easier entry level event. As such, the airplane design is restricted. The fuselage, of course, is a profile not a full body with a minimum length of 12 inches. The model must look like a conventional airplane with regular wings, a stabilizer, a canopy, an exposed two-line control system, two-weel undercarriage and an exposed side mounted engine. No exhaust system is permitted and the engine must run as an “open face”. The scoring of the 1/2A Profile is a standing start for one mile. That is, the timing starts the moment the model is released. Fuel may contain up to 10% Nitromethane.

1/2A Speed                                                                                    Engine size 0.05 c.i.

This class allows unrestricted airplane designs. They are full-bodied and streamlined to reduce drag. The model design may be a conventional or an asymmetrical design, and the current trend is to build asymmetrical models. Speed models do not have landing gear to eliminate drag – they use a takeoff dolly and land on the belly of the fuselage. Flight control is usually via a mono line system. 1/2A Speed is one of the speed classes that allows unrestricted exhaust systems. That means you can use a full wave tuned pipe. Fuel may contain up to 10% Nitromethane.

A Speed                                                                                          Engine size 0.15 c.i.

B Speed                                                                                          Engine size 0.30 c.i.

C Speed                                                                                          Engine size 0.65 c.i.

These speed classes allow unrestricted airplane designs. Models of conventional or asymmetrical design are full-bodied and streamlined. The current trend is to build asymmetrical models. Takeoff is from a dolly and landing on a skid on the belly of the fuselage. Flight control is usually via a mono line system. A Speed and B Speed classes allow unrestricted exhausted systems, and typically a full wave tuned pipe is used. D Speed is restricted to open face exhaust or mini pipe. A mini pipe is a straight pipe with constant diameter. Fuel may contain up to 10% Nitromethane.

21 Sport Speed                                                                            Engine size 0.21 c.i.

Formula 40                                                                                     Engine size 0.40 c.i.

Both Sport .21 and Formula 40 are intended to be easier entry level classes. As such, the airplane design is restricted. The model must look like a conventional airplane with regular wings and a stabilizer. The fuselages are a full body design but Sport 21 does allow profiles. In reality, fliers use the full body as it has less drag to slow the plane. Formula 40 also requires at least one wheel permanently attached to the model and must be used in takeoff and landing. These classes use a two-line control system. The exhaust is restricted to a mini pipe which is a straight pipe with constant diameter. Fuel may contain up to 10% Nitromethane.

21 Proto                                                                                         Engine size 0.21 c.i.

The purpose of .21 Proto is to fly semi-scale, realistic airplanes in C/L speed competition. Proto speed model do not need to be scale models, however, true scale models are highly encouraged. The model must have a full fuselage and rudder. Butterfly type stabilizers are not acceptable unless it is a true scale model. The model must have a clear canopy, a minimum dimension of 4 inches in length by 1 inch high and 1 inch wide and shall houses a scale pilot with a minimum of 1 inch in heightThe engine may have an open exhaust or a mini pipe type exhaust system only. Unlike other speed events, in 21 Proto models will be judged upon their appearance, and points will be given based on realism, construction, and finish; these points will be added to the speed score.

FAI Speed -F2A                                                                           Engine size 0.15 c.i.

This is the Formula One of speed classes. The F2A name refers to the FAI (Federation Aeronautique Internationale – the International Air Sports Federation) regulation section that governs this event. F2A speed is flown all over the world, and FAI holds a World Championships every two years in both individual and team classification. There is also the FAI World Cup competition with some 20 contests around the globe during the year. The Cup winner is determined by the three best performances.

F2A models are predominantly of asymmetrical design with a wing of up to 1 meter in length and a stabilizer on the outboard side. Unlike the AMA classes the FAI technical code limits the wing loading to 100 g per square decimeter and the minimum wing area of 5 square dm. Engines with the displacement of 2.5 cu. cm (0.15 develop a staggering 2.5 horse power spinning single-bladed carbon-fibre propellers at about 40,000 revolutions per minute, and this is achieved on fuel with zero Nitromethane – the standard FAI formula of 20% Castor oil and 80% Methanol.

Jet Speed 

Jets are really pulse jets. They are not the turbine engines that you see on an airliner. One can think of them as a series of explosions inside a long tube. Jet Speed models are fascinating to watch and are really loud. Please visit for more information.