Reprinted from August 2001, Vol. 38, No. 8
	By Tim Smith

During the time I was attending college in the early 1970's, the R/C bug bit me. As a young engineering student, the concept of building and flying a remotely controlled model airplane was extremely exciting. I jumped in with both feet, albeit on a starving student's income. I studied every aspect of the sport/hobby. The anticipation of each month's new issue of RCM magazine was overwhelming. I would read it cover to cover before the mailbox door closed! Many memories of airplanes, radios, and R/C products have stuck with me over the years. The original RCM Trainer is one of those memories. Although I never owned one at that time, I knew several fliers who did build and fly the RCM Trainer and loved every aspect of it. It handled well on the ground, was a very docile flier with excellent landing characteristics, and looked good to boot. What a combination. Global Hobby Distributors of Fountain Valley, California, has captured the essence of the original RCM Trainer in an extremely easy to build, almost ready to fly model. 

The Global RCM Trainer 40 ARF is a high wing tricycle landing gear trainer explicitly designed for the first- time R/C flier. The very attractive 46" x 13" x 7 .5" box draws you in with many full color pictures and graphics. All the information you need to know to get going with this kit is right on the box, making the initial purchase decisions very easy for the uninitiated. Details of all necessary accessories are not only described but also presented in full color photographs. The entire concept of this ARF is very well thought out. Opening the box reveals a well packaged model and accessories. There are four plastic wrapped packages in the box: the wings, the empennage, the fuselage, and the hardware. Nearly all items needed to finish this kit are included. Wheels, fuel tank, pushrods, clevises, and spinner are all included. All parts are very easily identified, and the hardware is bagged with like parts in the same bag. This adds to the convenience when you are trying to mount the landing gear, for example, and all the parts necessary to accomplish this task are in the same bag. Other items in the box include prebent pushrods, the landing gear wires, a very nice decal set, an RCM subscription form, an RCM Anthology Book order form, two genuine RCM decals, and a very complete final assembly manual. The manual will be discussed in more detail later. 

Once all parts are laid out on your workbench, you will quickly note that this is a very well built model. The "true-iron-on" polyester covering is tight right out of the box. Very little touch-up is necessary, and is easily accomplished with a standard covering iron if desired. The seams are very straight, with adequate overlap. The graphics are additional pieces of covering material applied over the base covering. Registration between the graphics pieces is excellent. All major assemblies, the wings, fuselage, and empennage, are straight and light.  Upon closer inspection, you discover the most exciting construction feature of this ARF: it bolts together! The RCM Trainer 40 ARF does not require any glue to assemble. The wing halves bolt together, and then the complete assembly bolts onto the fuselage. The horizontal stabilizer and vertical fin also bolt directly to the fuselage. All pilot holes for the screws and control horns are already drilled for you. Even the fuel tank stopper is assembled! As you begin construction, you will be very impressed with the quality of the 35-page final assembly manual. It is truly designed for the novice. Every step of the assembly process is detailed with photographs. The manual is arranged very logically, and each step has a corresponding check-off box so you won't lose track of where you are during the assembly process. Also included is a metric to standard conversion chart (all hardware in this kit is metric), full-size drawings of all included hardware items for ease of identification, and a comprehensive listing of all required additional items (radio, engine, glow plug, foam rubber, fuel line, and prop), recommended field equipment, and tools. The first step in completing this model is to assemble the wing halves. This entire step can be accomplished in about seven minutes. First, you locate the two hold-down screws, slide one wing half (with aluminum wing joiners pre-installed) into the other wing, insert the hold-down screws, and tighten. You are finished! All control surface hinges are pre-glued and require no attention except a simple tug to help you sleep better at night. It doesn't get any easier than this. The aileron servo and servo tray will be installed later. 

Next, the horizontal stabilizer/elevator is installed. Once again, it is a simple matter to locate the designated screws, insert the screws and tighten. The manual directs you to run a quick measurement check to verify the alignment of the stab with the wing. The review model was nearly perfect and no further alignment action was taken. Installing the vertical fin/rudder comes next. The bottom of the vertical fin has a mounting post inserted into it. Installing the fin is a simple matter of sliding the mounting post through the slot in the horizontal stab and out the bottom of the fuselage. The vertical fin is supported by angle stock attached to the horizontal stab, which fit tightly against the fin once it is inserted. All that remains is to install the supplied washer and crush nut to the mounting post and hand tighten with a 5.5mm socket. You can also use needle nose pliers (as suggested in the assembly manual), however, if you do, be sure you don't overtighten. At this point, you have about 20 minutes invested, and you have a complete wing and fuselage structure. 

Next comes the landing gear; main gear first, then the nose gear. Installation is very conventional for the main gear, and as stated before, the pilot holes are already drilled for the main gear attachment strap screws. I suggest that you round the inside corners of the main gear mounting blocks in order to allow the gear wires to seat completely. This only takes a moment with a Dremel tool, or a few seconds longer with an X-Acto knife. The nose gear installs easily per the instructions, and the nose gear wire has the appropriate flat spots already ground onto the wire. This is a very nice touch that eliminates the need to manually determine the mounting position for the steering arm, which can be difficult in a tight engine compartment. The nose wheel steering pushrod is factory bent with a z-bend and slides into a factory-installed plastic pushrod tube. The pushrod tube exits the firewall in a small horizontal slot, which allows the tube to move laterally as the nose wheel turns. This greatly reduces any nose wheel pushrod binding, which sometimes occurs in this type of aircraft. It is also another indicator of a well thought-out design. 

The final item to be installed in the fuselage (short of the radio system) is the fuel tank. The supplied 320cc (10.4 ounce) tank is pre-assembled. This is another nice touch for the new modeler. Fuel tank assembly instructions are included in the manual, in case the tank needs to be disassembled or replaced in the future. The tank slides into a balsa cradle in the extreme nose of the airplane. The stopper mates with a pre-drilled hole in the firewall. Once installed, the face of the stopper is flush with the engine compartment side of the firewall. All that protrude into the engine compartment are the vent and feed lines. The tank is held in the cradle by a piece of balsa and a piece of doubled 1/4" foam inserted between the top of the tank and the top inside of the tank compartment. 

Now that the airplane is sitting up on the gear with the fuel tank installed, the next step in the assembly manual is to install the engine. We used a Magnum XL46 to power the review airplane. This engine is a perfect fit. The engine bearers are pre-drilled and include factory-installed blind nuts. The Magnum dropped right in, the needle valve fit perfectly into a notch cut into the side of the engine compartment (specifically for this purpose ), and the supplied engine hold-down bolts and washers were of the correct size and length. We also used the stock muffler (included with the engine), and it fit perfectly into its notch also cut into the side of the engine compartment. Of special note here is that the supplied engine hold-down bolts are socket cap screws. This is an ideal fastener for engine installation, as it allows you to put proper torque on the bolts using an Allen wrench or ball driver. The final touch to complete the engine installation is to add the prop (not included) and the spinner (included). The prop cutouts in the white plastic spinner are factory-cut to accommodate a 10 x 6 propeller with no additional carving. At this point, you have essentially completed the assembly of the airplane. All that remains is the installation of the radio components, the control surface pushrods, and the control horns. Regarding the radio system, any of the mainstream 4-channel systems on the market today will fly this airplane adequately. 

This being a trainer-type aircraft, there is absolutely no reason to use anything but standard servos and a standard 500- 700 mAh battery pack. We used four Futaba S 148 standard servos which fit perfectly in the servo tray. When installing any of the servos, there is no need to use an electric drill (as suggested in the assembly manual) to drill the servo screw pilot holes. I recommend using the Great Planes Dead Center hole locator. This inexpensive device is equipped with a 1/16" drill and allows you to perfectly center and drill the servo pilot hole in one quick operation. The aileron servo is installed after the aileron servo tray. Remember that the wing has dihedral built into it, and the tray will not lie flush. Do not overtighten the tray mounting screws. The servo tray is cut to allow the aileron servo cable to exit on the side of the servo. The next step is to drop the servo in place, ensuring that the servo wire is properly routed, and install the servo mounting screws. The aileron pushrods and associated linkage install very easily per the well-illustrated manual. The rudder, elevator, and throttle pushrods and associated linkages also install very easily. The control horn pilot holes are precisely drilled in the rudder and elevator control surfaces, which makes control horn installation a snap. Of note here is that the supplied throttle pushrod was far too short, and the elevator pushrod was nearly too long. The throttle pushrod had to be replaced; the elevator pushrod was barely usable, as the elevator clevis was screwed on all the way to the end of the threads. (The manufacturer has been made aware of this. ) 

The last remaining task is to install the receiver and battery pack. As mentioned above, we used a standard Futaba battery pack and receiver. When installing these items, be sure to properly wrap them in foam. Once wrapped, the receiver and battery pack will not fit where the instructions suggest (which is under the forward part of the fuselage servo tray). As it turns out, the review model balanced tail heavy, so the battery pack and receiver were installed as far forward into the radio compartment as possible. Two ounces of weight were still required in order for the airplane to properly balance within the manufacturer's suggested range. The balance weights were installed immediately behind the fuel tank and glued to the fuselage floor.

 Now that the radio components have been installed and the airplane has been balanced, the final step before heading to the field is properly setting the control throws. If you carefully follow the assembly manual and connect the pushrods to the servo and control surface control horns in the suggested locations, your control throws will be nearly exactly as specified in the manual. If your radio happens to have an end point adjustment feature, you can more precisely adjust the control throws electronically. If the throws turn out to be larger than that suggested, you must perform either a mechanical or electronic adjustment to ensure you do not exceed the suggested throws. This is very important, as the low rate control throws are more than adequate for a first-time flier. The assembly manual provides very clear instruction on how to adjust the control throw(s) if necessary. 

Now for the part we've all been waiting for. Flying! The battery packs were charged up and off we headed to the field. As I was installing the wing assembly on the airplane at the field, I had several other sets of eyes take a peek at the control system and linkages. This is especially important to a first-time flier. Have your instructor (and others if appropriate) do a thorough visual inspection of your airplane before the first flight. Your airplane can never be over-inspected. I then performed a battery voltage check to be sure there was no malfunction in the airborne pack. 

After inspections were complete, we put a tank of Performance Plus 15% nitro fuel through the new Magnum to begin the break-in process and get the high and low speed needle valves set. Note: As mentioned previously, the engine provided with the review kit was the Magnum XL46 engine, also distributed by Global Hobby Distributors. My previous experience with the Magnum XL46 engine has been favorable; however, this particular engine was a bit finicky. After many attempts at tuning the low and high- speed mixtures, the engine refused to accelerate from mid throttle to full throttle without dying. Scratching our heads, we went on down to our local Hobby People store and purchased an XL46 off the shelf. This engine performed much better and managed to keep running during throttle transition, and was the engine used in the flight review. While the engine was running, we performed a very extensive radio range check. Engine vibration is always a potential issue, and we wanted to be sure we had perfect radio reception on the ground while the aircraft was experiencing its normal vibration environment. All went perfectly. 

After letting the engine cool and refueling, it was time to launch. As I smoothly advanced the throttle and the airplane accelerated down the runway, I made a mental note that the nose wheel steering was a bit too sensitive, but controllable. The flat bottom wing began flying very quickly and the airplane quickly lifted off the runway. As I climbed out, I was making mental notes on the trim configuration. I climbed to a safe altitude and entered a left-hand racetrack pattern to trim the airplane. At full throttle, very little trim was required. A bit of up elevator, and a bit of right aileron was all it took to have the airplane flying hands-off. Next was to get a feel of the control throws. Using the recommended low rate throws, the airplane presented a nice aileron/elevator balance. And good control response at all speeds. 

Next I checked both power on and power off stalls and found no problems here. Very little rudder or aileron control input was needed to keep the wings level. As soon as the nose dropped a little, it picked up flying speed and resumed normal flight. While not something that a new pilot will be doing, I did perform a few rolls and loops just to see how the RCM Trainer 40 handled these two maneuvers, and found that it will do both quite well for a basic trainer. The recommended control travel felt very good at all flight speeds and a good place for a new pilot to begin his flight training. If the factory control throws are used, and the factory C.G. is observed, approach to landing stalls are gentle and controllable. 

The final flight checks performed were landings themselves. I performed several touch and go landings to get a feel for the glide characteristics of the airplane. The flat bottom airfoil on this airplane performs exceptionally well during the landing phase. The wing flies all the way to the ground and slows down to a walk. Given a skilled instructor, a typical R/C student should be able to learn the fundamentals of landing in very short order. On about the tenth flight of this airplane, a normal landing approach was followed by a feather light touchdown. As soon as the nose wheel touched the ground, the nose gear collapsed! As it turns out, the nose gear bracket is attached to the firewall with four Phillips head screws and four nuts. Not blind nuts. Engine vibration had loosened the nuts on the back of the firewall, allowing the screws to pull out. When the airplane landed, the nose gear had nothing to hold on to! It appears that the bracket is installed on the firewall before the firewall is installed in the fuselage. Consequently, there is no way to get to the nuts on the back of the firewall to check their tightness. After pulling the engine and the fuel tank, I fixed my installation by replacing with original screws with #6 socket head sheet metal screws. Before installing, I packed the holes in the firewall with thick CA and put a bead of glue on the screws themselves just before screwing in. Alternatively, a small hole could be cut in the bottom of the fuselage in order to gain access to the space behind the firewall. This would allow insertion of a small wrench to hold the nuts while tightening the screws from the front. The hole can then be covered with a piece of covering material of your choice. Keep your eyes peeled for this condition and take action before your nose gear collapses! 

I believe Global Hobby Distributors has a hit with the RCM Trainer 40 ARF. The airplane is very easy to assemble, includes excellent documentation, and flies beautifully. The model and its final assembly manual are explicitly designed with the novice in mind. All details of required and recommended accessories are included in the documentation. If a novice were to buy this kit and follow the recommendations for the radio and accessories, they could feasibly get into the R/C hobby for a price of about $400.00 or less. That is excellent value in my mind. Global Hobby Distributors have captured the finesse of the original RCM Trainer at a price that is affordable to nearly anyone who desires to enter this exciting sport/hobby. Check this one out at your hobby dealers.

Editor's Note: Just prior to sending this issue to the printers, we received word from Global that all of the minor problems we encountered are now being corrected by the factory.