Great Planes: Tiger Moth ARF

Model Airplane News, Mar 2002 by Onorato, Jim

Originally developed from the D.H. Gipsy Moth, the de Haviland D.H. 82 Tiger Moth was first flown in October of 1931, and it eventually became the basic trainer for Britain's Royal Air Force (RAF). More than 8,700 Tiger Moths were manufactured, 4,200 of which went to the RAF where they were used to train thousands of pilots for World War II service. It continued to serve the postwar RAF until 1951, and more than 250 are still flying today. The Great Planes Tiger Moth ARF is a fry-scale replica of the famous trainer, and its construction and flight capabilities faithfully capture the timeless charm of that classic biplane.

ARF 1/5-scale timeless trainer

WHAT'S IN THE BOX?

The quality of this kit was obvious as soon as I opened the box. It's constructed entirely of balsa and ply and comes covered with Cub Yellow MonoKite. The kit includes hinges, wheels, preformed and soldered landing gear, an adjustable engine mount, a painted fiberglass cowl, a fuel tank, a spinner, cabane struts, interplane struts, decals, vacuum-formed windscreens and a very generous hardware package complete with all the necessary parts for the flying wires. In other words, it comes with everything you need minus the radio, engines, propeller, fuel tubing and pilot.

The major parts come individually wrapped in cellophane bags, and I was pleased to see that there were very few wrinkles in the covering. A manual full of photos and detailed instructions guides you through the assembly procedure without the need for a plan.

ASSEMBLY

Assembly begines with the wings. Only the bottom wing has ailerons, which I attached with CA hinges cut from a long strip of CA hinge material. After removing the covering over the two aileron servo openings, I installed two Futaba S3001 servos, the control horns and linkage, and then I glued the wing halves together with 30-minute epoxy. Three pieces of 1/8-inch ply make up the wing joiner for a combined thickness of 3/8 inch. A piece of string passes through the wing from the aileron servo to the root. Use this to pull the aileron servo lead through the wing later on. I cut out the exit holes near the root and passed the string up through these holes before joining the wing halves. The bottom wing has 2 3/16-inch of dihedral at each tip.

The next step given in the instructions is to glue the two top wing outer panels to the top wing center section. Do not do this! The dihedral in the top wing is not specified, and if you get it wrong (as I did), the interplane struts won't fit. I used the same dihedral as the bottom wing's, but that was too much. The interplane struts were too short and I had to make new ones. Instead of gluing the top wing together, go ahead and install all the mounting brackets on both wings and attach the bottom wing to the fuselage. Then attach the cabane struts to the fuselage and the center section of the top wing to the cabane struts.

Next, epoxy the top wing joiners into the center section making sure you wipe off all the excess epoxy; then let the epoxy cure. Last, apply 30-minute epoxy to the root rib and joiner pocket of one of the top wing panels, slide it onto the center section, and install the interplane struts before the epoxy cures. This ensures proper alignment of all the parts. Install the other top wing panel in the same way.

The cabane struts are painted black, but the interplane struts are covered with black MonoKote that was badly wrinkled. Since I had to make new struts anyway, I painted the new ones black.

The flying wires included with the Tiger Moth are neither functional nor are they required for structural integrity, but they sure do look great. They take quite a bit of time to assemble, but all the parts are provided, and the final result is well worth the effort.

After removing the covering from the areas to be epoxied, I epoxied the stab and fin into place. Everything lined up nicely without any cutting or shimming. All of the tail feathers are built up to save weight. I attached the elevators and rudder with the CA-type hinges provided and added the tailwheel assembly. I thought the stab support braces were a bit bulky-- looking, but they really strengthen the stab.

Great Planes recommends either a .61 2-stroke or a .91 4-stroke engine for the Moth, but there was no doubt in my mind as to which I would use. This plane is ideally suited to the power and performance potential of a 4-stroke engine, so I chose an O.S. FS-91 II Surpass. The kit includes an adjustable engine mount, and the proper thrust angle for the engine is already built in. I attached the engine mount to the firewall with 8-32 socket-- head capscrews and blind nuts. I used a Great Planes Dead Center Hole Locater to mark the location of the engine-mounting bolts, then drilled and tapped the mount for 8-32 mounting bolts. I mounted the engine inverted and used an O.S. Exhaust Header to allow the muffler to be positioned in the perfect location under the model.

Next, I assembled and installed the fuel tank in the fuselage with the neck inserted into the hole in the firewall. I put foam rubber in front of the tank and held the tank in place with rubber bands attached to hooks that I installed in the fuselage former. I used a two-line fuel system with a Great Planes Easy Fueler mounted on the firewall.