Realistic-looking, fun flight
from this 50-inch biplane
Geoffrey de Havilland’s Gipsy Moth was created in 1928 by replacing the 1925 Moth biplane’s Airdisco engine with a Halford 100 hp Gipsy engine. An instant success,
1, 162 were manufactured.
Frank B. Baker first saw one when it was housed in a hangar
near his own hangar. The thought of the biplane stuck in the
back of his mind, and he realized the Gipsy Moth was an
obvious model airplane design after purchasing an O.S. . 20
four-stroke engine. By enlarging Aeromodeller magazine three-views, the model ideally matched the powerplant
and a 9 x 6 propeller.
Frank stressed that the model was not lightweight,
and the builder should keep the weight down by
using epoxy sparingly, because it “adds weight in a
very insidious manner.”
Construction began with the wings because they
were the easiest part of the model and would be
needed to build the fuselage. Wing spars consisted
of top and bottom 1/8 x 1/4-inch spruce with balsa
sandwiched between. The wing ribs were stacked 1/16-
inch balsa blanks cut with a band saw. The rest of the
wing construction was standard.
The two fuselage sides were built directly over the
plans with the hardest 3/16 square balsa possible for
the top and bottom longerons. Frank made his own
fuel tank from K&S #254 easy-to-solder tin sheet. He
doubled the 1/2-scale pattern on the plans and cut the
After the fuselage was removed from the building
board, Frank built two 1/16-inch plywood rear cabane
strut fuselage doublers. He used a Robart incidence meter
to set the top wing to 30° incidence, stating that it was also
important to measure from the wingtips to the workbench
surface to make sure that the wing was level.
The cockpit hatch was a 1/32-inch plywood floor with
formers and 3/32-inch sheet bent over the formers. The 1/8-inch
square spruce stringers provided strength. A 1/16 plywood servo
hatch cover housed three servos on a side-by-side servo mount
or on two 1/2-inch strips of 3/16 plywood.
Tail feathers were of standard construction, with a 1/4 x
1/2-inch rear post in the vertical fin going all the way to the
bottom of the fuselage. Elevator hinges, the lower rudder
hinge, tail wheel assembly, and the upper rudder ridge were all
installed before the engine was added.
The top wing could be covered and painted before or after
it was mounted. Burnt umber stain was used to color the struts
before adding a coat of clear dope. Lightweight silk brought
back from a trip to Japan was applied wet to the fuselage and
tail feathers and several coats of clear coat were brushed on
when they were dry. The wings were covered with regular
An engine cowl was made, although Frank only used it for
photography purposes, and a 2-inch Williams Brothers pilot
was added to the rear cockpit.
Frank noted that the Gipsy Moth required coordinated
rudder, elevator, and aileron to make proper turns, but landings
were a joy. The airplane was predictable and operated in a
slow, stately manner.
“My Gipsy Moth has hundreds of flights,” he said, “and each
one was just plain fun.”
The Gipsy Moth was featured in the September 1994 Model
Aviation as AMA Plans Service number 768 for $14 plus
shipping and handling. AMA members can access the MA
Digital Library on the magazine’s website to read more about
this airplane and its construction. See page 145 or go to www.
modelaircraft.org/plans.aspx for ordering information.
99 Model Aviation JUNE 2015 www.ModelAviation.com