1/2A Scale rules
by Fred Cronenwett
John Rist’s Do 335: 1/2A Scale models seem to represent different aircraft that are not typically built for Sport Scale. One such model is the Dornier Do 335 Pfeil that saw
limited production during World War II.
John Rist scratch-built this model and installed a shaft
to drive the rear propeller as was on the full-scale airplane.
Because plans for this model are uncommon, John used MS
Visio to enlarge the three-view to create templates.
The rear engine is a Tee Dee .049 and the front engine is a
Noral AMD .061. The balloon fuel tanks are on the right side
of the fuselage and the rear engine is on the left side of the
fuselage. John designed the shaft and Jim Lee of Lee Machine
Shop machined it. He used a universal joint and a bearing for
Having the correct color information can make a difference
in the static score. John found documentation that showed the
camouflage pattern and RLM color numbers. The model is
painted with Klass Kote, which offers premixed paint for the
RLM color numbers.
He got the scale documentation, based on photos of the full-scale aircraft at the Smithsonian Air and Space Museum, from
Bob’s Aircraft Documentation.
1/2A Scale Rules
Because 1/2A Scale is not an AMA event, contests are run
under club rules. This event brings out the child in everyone
because at one point each of us has flown or done something
with these small motors. They can be frustrating and
challenging, but seem to draw smiles and good memories.
1/2A Scale is currently flown at the Circlemasters CL club
in Milwaukee; the Brodak Fly-In in Pennsylvania; the AMA
Nats and Fellowship of Christian Modelers (FCM) contests
in Muncie, Indiana; the Lafayette Esquadrille CL club in St.
Louis; the Cholla Choppers Model Airplane Club in Tucson,
Arizona; and the Central Arizona CL club in Phoenix.
The rules vary between contests. Some require .061 or
smaller engines and encourage multiengine models. Verify the
maximum engine size allowed before attending any contest.
Brodak established a set of rules that allows for single or
multiengine models. Bonus points are given for multiengine
models and static judging is done for outline, color, finish,
markings, and craftsmanship. Then you have to start all of the
engines, take off, and fly 10 level laps.
The model can be full-body or profile fuselage, but the full-body fuselage models do not have a scoring advantage. Building
a model such as this is a nice break from building larger,
detailed models typically found in Sport Scale.
The Cholla Choppers club has a different set of rules with
two categories. Limited is similar to the Brodak rules, but it
offers bonus points if you have multiple wings. The Unlimited
category allows pilots to use throttle control and you choose
three options during the flight.
The club has full details on its website for the contest and
This de Havilland D. H. 66 Hercules,
built by Lou Wolgast, placed first in the
Limited category at the Tucson 1/2A
Scale contest. Photo by Ken Gulliford.
The Dornier Do 335 Pfeil was scratch-built for 1/2A Scale. Photo by John Rist.
127 Model Aviation APRIL 2014