Scale Static Propellers

Large, vintage aircraft on display under clear blue sky.

Control Line Scale

By Fred Cronenwett | clscale7@gmail.com

As seen in the August 2026 issue of Model Aviation.

IF YOU FLY in Control Line (CL) Scale competition, the propeller that you show the static judges is important. They will look to see whether you have matched the configuration, outline, scale size, markings, colors, and details against the documentation that you provide for the full-scale aircraft’s propeller. The only event class in which this would not play a role is Fun Scale. I keep the flying propeller on the model during static judging for this class.

Large military aircraft on desert tarmac under clear blue sky. — The Martin Mars flying boat display at the Pima Air & Space Museum in Tucson, Ariz.

The more common propellers that are used on World War II warbirds are three- and four-blade Hamiliton Standard propellers. The full-scale aircraft you copied for your model might have used the Curtiss propeller, which has a completely different propeller hub and blade, so check closely. To be clear, the static propeller is only used during static judging and should not be to be used to fly the model.

Determine the scale diameter of the model’s propeller, and then match the diameter to the scale outlines on your documentation. Measure the model’s wingspan, and then use the full-scale aircraft’s wingspan to determine your scale factor. If you built a 1/8-scale model of the full-scale airplane, your scale propeller would be 1/8 the size of the full-scale propeller. If you are going to enter Profile, Team, or Sport Scale, the judges sit 15 feet away from the model, so some very small details do not need to be perfectly scale to get a good score.

The static propellers for my B-29 model needed some repairs, so I decided to make a new set. The hub was 3D-printed, and I purchased the blades. The hub design that I created was made to work with the existing collet adapters that interface with the electric motor.

Propeller with blue sky and three spare parts below. — The Martin Mars propeller has a unique shroud that covers the center hub.

Detail parts for the static propeller are painted individually prior to assembly.

Black four-blade propeller with yellow tips, five red oval logos below. — The assembled static propeller is ready for decals, and the propeller hub has a nut built into it.

Propeller of a vintage airplane seen from the front at an airshow. — The B-29’s full-scale propeller blade.

Close-up of a polished airplane propeller against a blue sky. — The B-29’s full-scale propeller hub.

The 12 × 7 replacement blades that I used on these static propellers were sold by Flightline. They are intended to bolt into a hub, but I instead glued them into the static propeller’s 3D-printed hub. When you paint the hub and the blades, pay close attention to the markings and paint. If the full-scale aircraft had stickers on the blades, you will want your static propeller to have the same stickers.

I like to store the static propeller(s) in a box to keep them from getting damaged.

2027 F4B Team Trials

The CL Scale F4B Team Trials dates for the 2028 FAI F4 World Championships for Scale Model Aircraft will be announced at some point by the National Association of Scale Aeromodelers (NASA). If you are interested in being a CL Scale F4B team member, now is the time to get your model started for the team trials.

The 2025 F4B Team Trials was held separately after the completion of the 2025 CL Scale Nats. The goal of the team trials is to determine the pilots who will represent the US at the next F4 World Championships, which will be held in 2028. Because the rules are very different from the AMA Sport Scale rules, you have to understand the differences between the two.

You can enter your F4B model in Sport Scale at the Nats and fly the same model in the F4B Team Trials because they are two different competitions. You will have to fly the model differently for F4B since it has fewer options in the flight portion. Another key difference is that level flight is higher than the AMA Sport Scale event.

Martin Mars

I recently visited the Pima Air & Space Museum in Tucson, Arizona. It now has the Martin Mars flying boat on display. Flying boat models are allowed to have wheels added to the fuselage and wing floats so that they can be flown from a hard surface.

The Martin Mars has a unique shroud that covers the propeller hub, and the blade appears to be wider than the blades on the B-29. If you build a Martin Mars, the shroud could easily be 3D-printed to create the proper Scale look.

Contest Calendar

There are two more CL Scale contests in 2026 in which you can compete:

Midwest Regional C/L Championships/NASA Scale Classic (CL only): September 5-6; Aurora, Illinois
Broken Arrow CL Stunt & Scale Contest: September 19-20; Buder Park, Valley Park, Missouri Land softly!