Global Avance

Model Airplane News, Jan 2003 by Luciano, Carmen

Fly like a pro with this sport-pattern ARF

Sport-scale aerobatic Sunday flyer

The Global Avance is a .46-size ARF designed for pattern-style aerobatics, but with a few minor changes in servo selection and wiring, it can also be set up as a sport plane. It's constructed of high-quality balsa and plywood and covered with iron-on film. It is built light and straight, which is what a pattern plane demands for precise, predetermined maneuvers. The model is complete right down to the propeller and the clear cowl template that makes installing the fiberglass cowl foolproof. The included custom mechanical retracts are a nice touch.

The 46-page instruction manual is well thought out and easy to follow with many photos and highlighted assembly points, and each section is prefaced by a list of the kit items required and the tools and supplies needed for assembly. The manual's last five pages contain everything you've ever wanted to know about trims, aerobatics versus sport setup, throttle and control-surface management, exponential and even a troubleshooting guide for trim problems.

I only added a .46 Magnum XLS engine, silicone fuel tubing, glue and the RC system. Construction of this low-cost ARF is relatively simple.

ASSEMBLY

* Wing and belly pan. 'I he wing halves are joined with the dihedral brace and epoxy. Ilie alignment was perfect out of the box (no sanding or trimming!). I reinforced the wing-root top and bottom with fiberglass, as the wing will have to endure high-(G forces during maneuvers. Wing mounting was easy; the doubler is predrilled and accurately aligned. I added plastic retaining clips to the mounting screws to prevent them from falling out into the fiberglass belly pan, which I then epoxied to the bottom of the wing. Maker FtK that you cut the wing covering just inside the outline of the belly pan So : none of the balsa is exposed.

* Tail feathers and hinging. The hinge slots are already cut, so it's easy to intall the hinges. Remember to put petroleum jelly on the center of the hinge to prevent glue from sticking to it and making it bind. I used epoxy instead of CA here--just my preference.

* Fuselage. The tailwheel assembly has a coiled spring, a nylon bracket and a tiller arm. For accurate alignment, I used wooden rails and clamps to center it on the rudder and fuselage. The engine is mounted on two separate composite beams. With a little patience, it's easy to properly orient the parts and attach the thrust plate and beams. Just remember that "right" and "left" are as if you are looking at the front of the plane. Three machine screws go into the preinstalled blind nuts in the firewall, and a fourth wood screw secures the right lower beam (don't forget to drill the firewall for this wood screw!). I used a Magnum .46 XLS engine. I find that my Great Planes Dead Center Tool accurately pre-taps the hole locations for the engine mount.

The instructions and photos weren't specific as to where to position the servo tray in the fuselage, so after a light sanding, I epoxied it into place just aft of the center fuselage former in the wing-- saddle area.

I used JR 507 servos for the elevator, rudder and throttle and 517s for the two ailerons, since I had these on hand. Make sure you pay attention to the orientation of the servo output shafts for clearance of the pushrods and pull/pull cables for the rudder.

* Pushrods and cables. The next step is to install the pushrods for the throttle, elevator and ailerons. The only problem here was the split elevator pushrod; inserting it into the fuselage was aggravating because of the fuselage formers and the angle I needed to insert it at. I highly recommend that you install the split elevator pushrod before you install the servo tray; it will make assembly a lot more enjoyable. I adjusted the throws for each control surface to the specifications in the instruction manual.

* Retracts. If you've never installed and aligned mechanical retracts, this may take a little longer to figure out, as it did for me. I mounted a lowprofile, JR BB retract servo with an output torque of 90.8 oz.-in. in position on top of the wing. The retracts come factory-installed on the wing rails, but to hook them up, you need to remove them first. Because the opening in the wing was perpendicular to the wing root (instead of parallel as in the photos in the manual), I had to hollow out the opening to make room for the servo tray. Because of this, I decided to reinforce this area with fiberglass. This wasn't a big problem; it just extended assembly time and complexity. Rather than glue the wheel liners into the wing, I used small wood screws with 1/8inch-ply reinforcing blocks under the wing balsa sheeting. Access to the landing-gear bays will be easier if you have to remove or repair the gear in the future. The retracts worked and cycled just fine.

FINAL ASSEMBLY

FINAL ASSEMBLY

I assembled the included three-line fuel tank with colored tubing to avoid mixing up the carburetor, vent and fuel-filler lines, then I installed it in the fuselage. The cowl alignment and installation was very easy compared with my past experiences. Why? Because Global provides a clear, two-piece molded template for trial cutouts for the engine and muffler parts. Adding the provided fuel filler, wing skids, decals, spinner and prop completed the project. I achieved the correct CG (54 inches behind the leading edge), by placing a 700mAh, 4cell battery in the fuel-tank compartment (suggested in the manual!). The plane balanced perfectly with this battery location. I also laterally balanced the model for better tracking in flight.