This item is discontinued.

GREAT PLANES TRACER
PRODUCT TEST REPORT
by Robert Hodgdon

Type: Sport or Pattern
Manufacturer: Great Planes Model Mfg. Co. PO box 9021 Champaign, IL 61826
Distributor: Great Planes Model Distr. Co.
Suggested Retail Price: $109.99
Wing Span: Advertised 52 1/2", Measured 52 5/8"
Wing Area: Advertised 514 sq. in., Measured 512.6 sq. in.
Airfoil: Symmetrical
Fuselage Length: Advertised 54", Measured 55 1/16" (with Fox spinner)
Rec. Controls: 4-5 (Ail, El, Rud, Throt)
Rec. Engine: .40-51 2C, .52-70 4C
Rec. Weight: 5 to 5.5 lbs
Basic Material: Balsa and lite-ply, with an ABS plastic cowl
Instructions: 48 illustrated pages
Plans: Full size
Hardware Included: Composite engine mount with hardware, ABS cowl with fasteners, servo tray, pushrod materials, servo connectors, aileron hardware, control horns, hinges, clear plastic canopy, preformed music wire main gear and mounting hardware, preformed music wire tail gear, tail wheel bracket, wheel collars, wing bolts, miscellaneous hardware, and decals
Items Needed to Complete: Spinner, propeller, engine, fuel tank and lines, 4 ch radio w/5 servos (5 ch radio w/6 servos if using retracts), 2" main wheels, 3/4" tail wheel, adhesives, covering, paint for cowl, and optional pilot figure.

COMPLETED MODEL
Finished Weight: 7 lbs. 6 oz.
Wing Loading: 33.15 oz./sq.ft.
Engine Used: O.S. FS 70
Propshaft to Ground: 7"
Fuel Tank Used: Sullivan SS-12
Radio Used: Futaba 9ZAW
Covering/Finishing Used: MonoKote
Special Items: Fox 2 1/4" alum. Spinner, Kraft 2 1/4" main wheels, and Rhom-Air retracts.

CHEERS - Very complete kit; top quality materials; ease of assembly; excellent parts fit; overall good looks; excellent flight characteristics.

JEERS - Test model came out much heavier than advertised; die cutting error in fuselage side

Did you ever want to build a pattern plane and try your hand at competing in pattern contest? But you thought it was too expensive? Well, Great Planes has released a new sport/pattern kit called the Tracer, and it's an all wood, straight forward design, that resembles a lot of the current pattern aircraft. It can be flown using any 4-ch radio (5 ch if you use retracts), and an inexpensive .40-50 size 2C engine. I competed in pattern from the early 7's through the mid 80's and it has changed quite a bit since then. I too have been discouraged by the high cost of today's pattern aircraft, but I still enjoy the smooth flight performance of pattern designs. With the introduction of Great Planes' Tracer, one can now build a plane that looks and flies like their larger counterparts, but for a fraction of their cost.

The kit come in a brightly colored box that's fully packed with rolled full size plans, a 48 page instructions book, all the balsa and plywood needed to build the model, and a very complete hardware package. In fact, I didn't have to purchase anything else in the way of wood or hardware to complete the model.

Building the Tracer was a joy, with remarkably few problems. In short, the kit pretty much just fell together! The parts fit is simply excellent.

I like to start with the tail components, and the instructions begin there as well. The rudder and fin are assembled over the full size plans from 1/4 x 1/2" stock in an open frame configuration left unsheeted. The stab is constructed of 3/16 x 1/2" framework with 3/16x1/4" ribs, and then sheeted with 1/16" balsa, which yields a strong but light structure. The elevator is simply cut from 1 3/4" standard trailing edge stock. All components are then sanded to final shape, and ready to be assembled to the fuse.

The wing is constructed mostly of balsa, with lite-ply used as needed for the dihedral brace, dowel platform, and retract servo tray. The landing gear is mounted on basswood rails, using retracts or fixed gear. The wing is built upside down over the plans, completing as much construction as possible before removing it. The instructions show to build the wing in two panels and then join them. I chose to cut the wing plan, tape the two halves together, and build the wing in one piece. We start in building the wing spars by laminating 1/8 x 3/8 basswood strips 30" long using medium CA, and then pinning the main spar down on the plans. Then a 3/16" sq. balsa stick is pinned to the plans to support the ribs near the trailing edge. Remember, the wing is built upside down over the plans, and there are several ribs that have a top and bottom. None have building tabs on them, however, to help identify which way they should go, so proceed with care. The ribs to keep in mind are R-3 and R-4, which support the landing gear mounting rails, and R-3 also has a cut out for the aileron servo tray.

Now is the time to decide between fixed or retractable main gear. The instructions include directions for both, and I chose retracts. I also decided to use pneumatically operated gear, and to enclose the entire system in the wing, locating the air tank between ribs and behind the spar. The operating valve will be on the bottom of the wing center section, enclosed in the belly pan. The die cut knock out from the belly pan bottom was used to make an access hatch. Then a Futaba S-3101 mini servo was installed in the normal retract servo location, to operate the retract valve. Ribs R-3 and R-4 have plywood doublers added to support either type of landing gear. Select the appropriate doubler and make a left and right set of ribs using medium CA. Then start adding the ribs on the spar, securing them with thin CA at the locations noted on the plans. Then add the bottom spar, landing gear mounting rails, shaped leading edge and trailing edge, followed by the sheeting for each, finishing up with the 1/16 x 1/4" cap strips. Then repeat these steps to build the other wing panel.

At this point, you can cut out the opening for the retracts and wheel wells. I chose to wait until the entire wing was completed except for the top leading edge sheeting. This will allow routing of the air lines (or mechanical linkage) that operate the retracts. 1/16" sheeting was used to line the retract wells. The air lines were then routed around behind the heel well to the center of the wing. The wing was then set in the wing jig to insure proper alignment, and the top wing sheeting and cap strips were added. The aileron/trailing edge was then installed using the shaped trailing edge stock. The instructions suggest cutting a 4" and a 2" piece from each 30" length of aileron stock, and then glue them to the trailing edge of the wing, with the 2" length at the tip, and the 4" length at the root. This method, however, makes it difficult to ensure that they are in proper alignment at the tip and root in conjunction with the aileron itself. An easier way is to mark the trailing edge of the wing 4" out from the center in each direction, and 2" in from each tip. Tape each piece of uncut aileron stock to the trailing edge of the wing, joined at the center of the wing. Ensure that both are properly aligned with the center line of the airfoil. Then, using thin CA, flue just 4" at the root, and 2" at the tip of the aileron stock, to the wing's trailing edge. Then use a square to mark the aileron using the marks on the wing, and using a thin-blade saw, cut off the unglued aileron portion. This process takes all the guess work out of lining up all three pieces, it's much easier, and it saves a lot of time. After final sanding, the wing is set aside with the tail components, awaiting the fuselage.

The fuselage is constructed primarily of balsa with lite-ply doublers and formers, but some cub assembly is required. The firewall pieces are laminated together, and the former F-2 and its doubler are glued together. Then the fuselage sides, with the three die cut pieces; aft, forward, and lower forward pieces, are assembled. This is where I encountered one minor problem. On the forward part of the rear fuselage side where it fits together with the forward fuselage side, there is a slight convex curve in the tongue which prevents the two pieces from properly aligning. Luckily, the fix is very simple. Take a sanding block and sand the tongue flat. Then I took a 60" straight edge and lined the top of the fore and aft fuselage side pieces along the edge, and sanded the joint to fill in any gaps with sawdust, before using thin CA to fill and bond the joint. This ensures a straight fuselage. Since the wing and stab incidence depend on this stop, it is very important that it is perfectly straight.

Then attach the small lower front side pieces, and using thick CA, attach the lite ply fuselage doublers to the sides, making sure to make a right and left side. Also, since the firewall has a 3 degree right thrust angle pre set by the slots in the lite ply doublers, make sure they are oriented in the correct direction, or the fuselage will be built with left thrust instead! Don't worry, because the instructions point this out in good detail. Complete the sub assembly work by joining the two balsa fuselage top pieces together, using the plans for alignment.

Now the real construction can begin. The fuselage top is pinned to the plans, and then the formers are added. Then the fuselage sides are attached to the top and formers.

Using the O.S. FS-70 Surpass engine made the plane nose heavy, so I installed the elevator and rudder servos behind former F-4A. The balsa knock-out from former F-4A can be used as a hatch to allow access to the servos, if desired. The battery can then go in the compartment intended for the servos. Without these or some other stops to redistribute the weight of the radio gear, several ounces of weight will have to be added to the tail to properly balance the model.

Now the rear fuselage bottom is glued in place. Then the wing is attached to the fuse, and the belly pan assembled and positioned on the wing. The wing bolt holes are drilled at the marked locations on the wing bolt plate. Once satisfied with the overall fit and alignment, the belly pan is permanently glued in place, and the wing is removed from the fuse.

Now the fuselage is removed from the building board, the pushrod tubes are installed, followed by the firewall, using slow cure epoxy. The fuel tank hatch is sanded to fit the opening on the lower front of the fuse, and held in place with the supplied screws. The turtle deck formers are added, and the 1/8 x 1/4" stringers are CA'd in place.

Here I encountered another minor problem. The distance between the formers was too great for the soft balsa stringers to handle the load of the turtle deck sheeting, so a dip occurred between F4B and F5B. There should be another former here, or hard balsa stringers should be used, and care taken to insure that the stringers are not deformed when attaching the sheeting in this area. I was pretty careful here, but I still ended up with a noticeable depression in the turtle deck on the right side of the model.

After the sheeting was added, the 1/4" thick top was CA'd in place. Now the front deck formers are added and the 1/8 x 1/4" top stringers installed, followed by the 1/4 x 3/8" side stringers. After this is done, fill the small gap formed at the joint of the fuselage sides and the side stringers, with a piece of scrap balsa to ensure a good joint for the top sheeting. The 3/32" top front sheeting is then added, making the fuselage ready for sanding. I used a sanding block with 180 grit paper to round the top of the rear fuse, and then sanded the front sheeting flush with the fuselage sides. Then I used 320 grit for final sanding on practically everything.

With the final sanding completed, the wing is bolted into place, and the stab is installed and aligned before gluing with slow-cure epoxy. Then the fin is epoxied in the slot above the stab, with the rudder post reaching to the bottom of the rear fuse. Once the epoxy has cured, the model is checked for any touch up sanding required. Then the hinge slots were cut in the control surfaces and their mating areas.

I used yellow Top Flite MonoKote to cover my Tracer, with typical excellent results, using red and black for accenting trim.

The two piece ABS cowl is cut from the single vacuum formed piece. Then several 3/8" wide strips are cut from the scrap, and attached to one side of the cowl at the seam, with one piece running from front to rear at the top, and another at the bottom. A small piece is added in the front, right below the prop shaft opening. Then the two pieces are joined and the joints reinforced inside with 1" wise 3/4 oz. glass cloth and slowcure epoxy. The seams were filled with automotive body filler, sanded smooth, primed, and painted with Top Flite Missile red LustreKote paint.

The control surfaces were attached after covering, and then the radio was installed. The Great Planes motor mount was drilled for the O.S. FS-70 Surpass, and installed with the supplied hardware. The retract system was then installed and tested, with no problems noted. I added an instrument panel decal from another kit, while the Snoopy head came from a discarded toy. Then the canopy was trimmed to fit, glued in place, and sealed with matching MonoKote strips.

The finished model balanced nose heavy, about 1/2" in front of the recommended CG location, but was left there for the first flights. The control throws were set up at the recommended amounts with the dual rate switches set to Hi. The low rates were set to 65% of the high rate. The model was then thoroughly inspected to ensure everything was installed correctly, and that the controls were operating in the proper directions.

During the 30 years I've been building R/C models, I've rarely had one come out as light or lighter than the suggested weight. Admittedly, most of my models somehow weigh a bit more than they should. It is extremely rare, however, to have one come out this much overweight! At 7.4 lbs., my Tracer weighs nearly 2 lbs. more than the advertised weight range of 5 to 5.5 lbs.! This is more than a little puzzling. Gordon allows no significant modifications to review kits, so this one was built almost exactly by the supplied instructions. I e-mailed Great Planes to ask the weight of their prototypes, and was told that one powered by an O.S. .46 FX with fixed gear weighed 5 lbs., and one powered by an O.S. FS-70 Surpass with mechanical retracts weighted 5.5 lbs. The only difference between theirs and mine is that I used pneumatic retracts. My entire retract system, including the wheels, weighs 9 oz. A suitable mechanical system weighs about 5 oz., leaving a net gain of 4 oz. But this till leaves the model 26 oz. overweight! Since the model was constructed with CA adhesives and about 2 oz. of epoxy, I've ruled out excessive glue. There was no ballast used to balance the model, either. Frankly, I'm looking forward to hearing from others who have built this model, with special interest in their completed weights.

Despite an early threat of rain, I was treated to a beautiful afternoon the day I first flew the Tracer. After the usual last minute checks, I filled the fuel tank, charged the retracts, and ranged checked the radio. Everything indicated a go! I started the engine, allowed it to warm up, and then taxied out to the center of the runway, and nosed into the breeze. Advancing the throttle smoothly forward, the Tracer accelerated down the runway, requiring only a slight amount of right rudder to maintain a straight heading. Then it was in the air. The model tracked straight, but needed a few clicks of up trim to maintain a level heading. It had been a long time since I'd last flown a pattern design, but the feeling was immediately recognizable. After making a few passes for the camera, and gaining confidence in its smooth demeanor, I decided to see if the Tracer lived up to its name. I began with a 4-point roll, followed by a Cuban 8, and then a square loop to test its vertical abilities. The Tracer performed every maneuver effortlessly! I followed that with several rolls and loops. The FS-70 Surpass pulls the Tracer with absolute authority, so I decided to really test its vertical performance. From about 50' of altitude, while the model was right in front of me, I directed the Tracer straight up, and slowly rolled to the right until I was looking at the top of the plane. And I watched it climb. And climb. And: well, I soon decided that it was either time to throttle back or donate it to the angles, because it was quickly becoming little more than a dot in the sky, and it didn't seem to be slowing at al!

At the top of the climb, I performed a stall turn and let the Tracer descend, performing another 14 roll to the right with the engine at idle, and then pulled out at about the same 50' altitude I'd entered the maneuver. If this model has any problems at all, a lack of power is not one of them!

I decided it was time to check out the Tracer's stall characteristics. Climbing to a safe altitude, I throttled back and slowly added more and more up elevator, until the nose dropped. As expected, since I'd balanced it slightly nose heavy, it fell straight forward with no surprises whatsoever. Then I put it into a spin, and after several revolutions, I released the sticks. The Tracer stopped spinning immediately. A little up elevator leveled it out.

It was time to land. After flying the standard traffic pattern, I lined up on final approach, lowered the gear, and watched as the Tracer tracked straight as an arrow for the runway. I flared the model for the first landing, which as a little hotter than expected because of the nose heavy condition, but it was otherwise uneventful. The model was refueled and flown two more times that day, all with the same pleasing results.

I moved the battery back under the servos as far aft as possible. The model then balanced at the forward edge of the CG range shown on the plans. Since the planes was already overweight, I didn't want to add even more, since repositioning the battery accomplished the intended goal. Subsequent flights were carried out with even greater success. The landings were significantly slower than the first few flights, and I was able to remove the slight up trim. What remained, however, was the highly pleasing, rock steady flight performance. It's small, perhaps, but it's a pattern design for sure!

CONCLUSIONS: The Great Planes Tracer truly lives up to its name. It literally traces the intended pattern maneuvers through the sky, going exactly where you point it. The kit itself was a joy to build, with excellent parts fit throughout. Building the Tracer took only two weeks, working two to three hours per evening, and even though mine appears overweight, its overall good looks and totally satisfactory flight performance leave me more than happy. Great Planes has produced still another model that's easy to build, well engineered, and offers excellent flight performance for any pilot with average skills. The Tracer provides the average Sunday Flyer the opportunity to experience the thrill of pattern flying, without the great expense. Even if pattern competition is not your cup of tea, the Tracer still make a fantastic sport model, that will make the average flyer look better than average in the air. As for me, the Great Planes Tracer is a keeper!