TOP FLITE T-34B Mentor GOLD EDITION

Model Airplane News, Aug 2004 by Corbett, Bobby

Tandem warbird trainer

The T-34 Mentor is the military version of Beechcraft's popular civilian aircraft, the Model 35 Bonanza. In anticipation of the U.S. Air Force's great need for trainers for jet pilots, the first T-34 was built in 1948, but USAF officials were torn between two training methods: whether to use a piston-powered plane, such as the Beechcraft, as a transitional trainer or simply to train pilots in existing jets. At last, a decision was made in favor of the Beechcraft, and in 1954, the Air Force-and, shortly thereafter, the U.S. Navy-adopted the military version of the Bonanza and renamed it the "Model 45 T-34 Mentor." More than 100 of these planes are still flying today, and the T-34 has a loyal following among warbird owners and operators worldwide.

THE KIT

Top Flite's 1/5-scale, T-34B Mentor Gold Edition kit features all-wood, die-cut balsa and lite-ply construction. The wing features a sturdy I-beam wing-spar design that simplifies construction. Flaps also add to the model's scale appearance and greatly improve its overall performance; they're worth the extra effort it takes to build them. The wire landing gear is prebent, but I felt that a model of this stature needed retracts, so I chose to use Robart's (item no. 630BNZ); they're specifically designed for the T-34B, and I highly recommend them.

The kit is built using the same construction methods as Top Flite's civilian Beechcraft Bonanza; the tandem seats in the fuselage, the rudder and the larger fin are, however, departures. The canopy comes in two parts so that it can be made to slide open, and Top Flite offers an optional cockpit kit for a final scale touch. One useful item included in the instruction manual is a tear-out sheet that shows the plan in a reduced size. The kit includes a full complement of hardware, and the instruction manual (it's more like a small book) is highly detailed with many in-process construction photos. There are also little tricks of the trade. They call them "Hot Tips," and believe me, they do help. Overall, this is a very well-outfitted kit.

CONSTRUCTION

During construction, I used thick, medium and thin Great Planes Pro CA and 5- and 30-minute epoxy where necessary. Another must-have is Great Planes' Plan Protector; it really helps prevent subassemblies from sticking to the plans when you assemble them.

Before starting construction, I read the manual and identified all of the die-cut patterns to familiarize myself with them. Do not remove any of the wing ribs until you're instructed to do so; this helps to keep them organized. As with most kits, you should have at hand all the accessories necessary to complete the project; this saves a lot of time (and frustration), especially during those late-night building marathons when the hobby shop is closed!

* Tail surfaces. Building them is the first step, and it's a straightforward, simple one. First, assemble the stabilizer, elevator, rudder and fin skins as instructed, and before the glue dries, make sure that the sheets are flat. The skins are oversize, and the kit includes templates to help you cut them accurately to the proper size. The tail surfaces are built over the plans, and the ribs for them all have jig tabs on their bottom edges; this results in a true, straight, flat surface. When you align the ribs, use a small square to make sure that they are all truly vertical. The computer-aided design ensures that the parts fit very precisely or tightly; they can almost be assembled before you add any glue. After you've built the basic frames, sheet them, and then cut the elevators and the rudder free. As you prepare to sheet the tail surfaces, be careful not to change the shape of the airfoil.

* The wing. The wing is built in three sections: the two outer panels and the center section. Make sure that your building surface is flat and that the rib's jig tabs are securely pinned to your work surface as you build. Before you begin construction, you must decide whether you're going to install retracts and flaps, as the rib subassemblies need to be built accordingly. Top Flite recommends that you build the right wing panel first so that your progress matches the photos in the manual. This is great advice.

Lay the ribs and spars over the plan, but do not glue anything until the instructions tell you to do so. The spars and ribs interlock, and they fit well. Make sure that the spar web fully contacts the bottom spar. Top Flite includes a die-cut, 90-degree gauge to help you keep the ribs vertical as you glue them. After you've glued the ribs and spars together, add the top spars and the leading edge to the panel. Sheet the top of the panel on the building board with the rib tabs flat on the table; be careful not to twist the wing. Remove the panel from the building table, and add the flap and aileron sub-ribs. Now build the left panel in the same way.

At this point, I installed the Robart retracts. Their installation went without a hitch, but it's very important that the gear rails be perfectly flat. Now add the hinge blocks, servo rails and hatches, and bevel the trailing-edge sheeting. Then set the panels aside, and build the center section. It, too, has subassemblies that must be built before it's framed up. After you've built the center section, sheet the top of it. Then prepare the dihedral braces, and fit them to the wing panels. Dry-fit the three wing panels together, and check their alignment. When it's perfect, separate the panels so that you can sheet their bottoms. Use a balsa cradle to align the wing panels while you sheet them.