GREAT PLANES T-CRAFT
PRODUCT TEST REPORT
by Hollis Fenn
Type: Sport Scale Aerobatic
Manufacturer: Great Planes Model Mfg. Co. PO Box 788 Urbana, IL. 61801
Distributor: Great Planes Model Distr. Co.
Suggested Retail Price: $139.99
Box Dimensions: 37.5 x 7.5 x 4.5"
Wing Span: 56"
Wing Area: 497 sq. in.
Fuselage Length: Advertised 40-3/4"
Req. Controls: 4 (Ail, El, Rud, Throt)
Req. Engine: 20-32 2C, .26-30 4C
Req. Weight: 3-3/4 to 4-1/2 lbs.
Basic Materials: Balsa and lite-ply
Instructions: 48 pages
Plans: Two 36 x 46" sheets
Hardware Included: Engine mount w/hardware, pushrods, control horns, hinges, FasLinks, nylon wing bolts, one screw lock connector, and misc. nuts, bolts, screws, and washers.
Items Needed to Complete: Spinner nut, propeller, engine, fuel tank and line, 4 ch radio w/3 std and two mini (or micro) servos, one Y-harness and two 24" extensions, two 2-1/2" main wheels, one 1" tail wheel, 5/32" and 3/32" wheel collars, adhesives, two rolls of covering material, and matching fuelproof paint.
Finished Weight: 3 lbs 12 oz (60 oz)
Wing Loading: 17.38 oz./sq.ft.
Engine Used: O.S. .20 FP (9.4 oz.)
Prop Shaft to Ground: 7.5" (held level)
Fuel Tank Used: Sullivan RST-6
Radio Used: Hitec Flash 5
Covering/Finishing Used: Carl Goldberg Ultra Cote and Chevron Perfect paint.
Special Items: Great Planes 1/4-28 Aluminum Safety Spinner Nut.
CHEERS - Builds light; flies well; very aerobatic, but has a nice flat glide for landing; a good entry level sport scale aerobatic design.
JEERS - Problems with instructions (see text); wheel pants don't fit well; side window material (see text); die-stamped part numbers difficult to read; landing gear fairings are held in place with short sections of rubber band that are glued in place.
The Great Planes T-Craft 20 is a sport scale model of the clipped wing Taylorcraft, which is an aerobatic light plane and an air how favorite. You may notice the resemblance to the Piper Cub, which began as a Taylor Brothers design. They sold out to Mr. Piper in 1930, but then went on to produce their own aircraft designs. I decided to finish mine in Cub Yellow to have some fun at the field, and it worked. When I took the model to the field the first time, one of the first comments was, "So you finally decided to do a Cub!" NOT! (heh, heh)
The Great Planes T-Craft 20 kits arrives in a sturdy, well packed, and attractive box. The box photos include the completed model, a famed up model, 4C and 2C engine installations, and an alternative color scheme. There are also lists that give the airplane's specifications, and the additional items needed to complete the model. The 48 page instruction manual features the now familiar Great Planes thoroughness for building, finishing, and operating the airplane. However, I did find a few confusing points that I'll mention as we go along. The plans are well drawn, and helped to clarify the points of confusion.
The construction technique is the familiar Great Planes sequence of tail, wing, and fuselage. The tail parts are all made from a few die cut balsa parts and balsa sticks. This is very light and easy to build, and no problems were noted with these parts.
The wing is a strong D-tube semi-symmetrical design built upright over the full view plan. The problem is, once you've taught an old dog a new trick, it can be even harder to re-train him. I've built a lot of Great Planes and Top Flite models where the wing is built upside down. Now, this is not a problem with the plans or the instructions, and the wing ribs do have tabs on the tops and bottoms, but I glued a few ribs in place upside down, and later had to cut them free when I discovered my error. That slowed me down a bit. I then encountered a problem with the aileron bay's trailing edge. The instructions on page 13, item 16, have you center the wood. But it turns out the part should be installed with the 1/16" overhang past the tops of the ribs. I also had some problems with the provided trailing edge sheeting, which was not the size called for in the instructions. But that wasn't difficult to overcome either. In addition, the 1/4" sq. balsa aileron bay trailing edge stock is not properly detailed on the plan, and the photos are hard to see in this area. Just be sure that wood is provided for the end hinge.
The ailerons are built up on this model, and no problems were encountered there. They're light, strong, and realistic. Two mini servos operate the ailerons, requiring a Y harness and two extensions to reach the servos. No provisions are made for tubes for the servo leads to the ailerons, so when I finished the wing, I covered the bottom first, then installed the servos and the extension leads, and then covered the top.
The fuselage is built up from die cut balsa and lite ply parts. The sides are balsa sheet and stick parts. The doublers, formers, and firewall are lite ply. The top longerons of round metal rubbing is simulated by wooden dowels, and they look quite realistic when covered. The only problem I had with fuselage construction is that the die stamped part numbers on the balsa parts were faint and difficult to read.
In my opinion, this kit's plastic parts are not the usual Great Planes quality. The windshield molding definition was not visible in places, and when the part was cut out, I found that it was not symmetrical. The wheel pants and cowl parts are to be glued edge to edge, with no lip overlap to strengthen the joint. And when the pants were assembled, they were not identical, and the grooves for the landing gear wires were not molded right for a proper fit. I couldn't get them to work well, so I just left them off. I didn't like the attachment method for the landing gear fairings, either. They have us use rubber bands, glued in place! The cowl spacing was wrong, too, so I had to make a 1/4" plywood spacer to fit between the firewall and engine mount.
Once the model was completed, I then had to wait for decent weather to paint the cowl, and more good weather to make the maiden flights.
Good weather finally came, the cowl was painted, and the test flight day was scheduled. After all the usual pre-flight checks revealed no problems, it was time to fly.
The first take off was straight and true. The T-Craft lifted off and climbed out well, and I needed only a little down and left trim for good level flight. I was very pleased to note that the complete model built up to the minimum weight advertised, so the little .20 2C engine pulls the plane with good authority. The loop and roll performance are very nice.
My oldest son, Michael, now 13, went to the field with me, and he flew the T-Craft during the first flight so I could take the mandatory photos. He found the plane very easy to fly. The landing was particularly easy, as the plane has a nice, long, flat glide.
In subsequent flights I was soon doing snaps and spins and more. The T-Craft 20 really does live up to its heritage, and is quite a snappy performer. I had aileron and elevator at the recommended low rates, with the rudder maxed out with all the throw I could get.
But... right after a snap roll, I started getting glitches in roll response, so I throttled back and headed for a landing. It settled down when throttled back, so I thought I had it made. But on final approach, at just 7' high, the plane banked 90 degree to the left and went in on the left wing tip, cart-wheeling to a stop. The wing pooped off, so I expected the worst, but the wing bolts had broken as designed (a first for me), so only the wing tips were damaged, and one landing gear fairing had come loose. It was an easy repair for such a crash.
I later determined that either the left aileron servo gears stripped during the snap roll (it was an old and well used servo), or the Y harness and extensions may have caused the problem. I'm not sure yet.
We flew the model enough that first day to know that it's an aerobatic but well mannered plane, made possible by its low wing loading and high wing placement. I consider the Great Planes T-Craft 20 to be a good entry level sport scale aerobatic design. The building problems I encountered were mostly minor, and the finished product made it all worthwhile. I believe the model is IMAC legal, too, so check it out!Reprinted with permission.
May, 2001 R/C Report
Editor: Gordon Banks