GREAT PLANES: Christen Eagle II

Model Airplane News, Apr 2004 by Reid, John

1/3-scale showstooper

The Christen Eagle II was one of the best flying acrobatic biplanes ever built. I knew that Great Planes would stay true to the plane's scale outline and style, but would this model be an outstanding aerobatic performer? Well, I'm happy to say that it is! The Great Planes Christen Eagle II has the same great looks as the full-size aircraft and a fantastic color scheme, and it is the easiest-to-fly biplane I have ever flown. It can tumble across the sky in aerobatic gyrations that would make even a diehard Edge 540 or Extra 330 pilot smile. It's definitely a plane that you will never get tired of flying.

OPENING THE BOX

All four wing halves and the tail feathers arrive wrapped in plastic and protected by bubble wrap. Accessories include the canopy, landing gear, wheel pants, cabane and wing struts, flying wires with metal brackets, tail-gear assembly, tank, engine mount, decal sheet and spinner. The hardware package includes just about everything you need for assembly. A 51-page instruction manual gives details for mounting three types of engine (one glow and two gas) and for installing the flying wires.

CONSTRUCTION

* Wing assembly. Following the instructions, 1 started with the wings, which took only an evening to complete. The bottom wing joiners have to be glued together with 30-minute epoxy; while the glue was curing, I removed all the wrinkles in the wing covering. The next step was to install the four ailerons; this went quite fast. No real tricks here: insert T-pins through the middle of the hinges, slide them into the hinge slots, apply six to eight drops of thin CA and let it dry.

When I test-fit the wing panels, I adjusted the wing joiners by sanding them with a sanding block. When I was satisfied with their fit, I mixed 30-minute epoxy, applied it to the wing roots and joiners and then pushed the wing halves together. The manual shows a great idea for wiping away the excess epoxy that oozes out of the joint. Cut small squares of paper towel (eight per sheet), and use these and rubbing alcohol to clean off the excess epoxy. When the joint was clean, I used strips of masking tape to hold the wing halves together until the glue had cured.

The upper wing assembly is completed in the same way as the lower wing, but the wing halves are attached to a center section. When you epoxy everything together, be careful to ensure that you don't glue the string that you'll use to pull the servo wires through the wing to the inside of the panels. To avoid doing this, pull the string back and forth a few times as the epoxy dries. I was somewhat negligent and allowed one string to become firmly attached to the inside of the wing. Don't let this happen to you.

With both wings assembled, all I had to do was install the control horns and the servos and hook the linkage up to the ailerons. Again, this took much less time than I had anticipated; I finished both wings in just one evening.

* Fuselage. Assembly begins with the tail feathers. I removed the MonoKote from the cutouts for the stabilizer and servos. I put the rudder and elevator servos in the cutouts and drilled the screw holes. Then I removed the servos, and I added a few drops of thin CA to strengthen the holes. I squared up the stabilizer with the fuselage and bottom wing. With everything lined up, I marked the stabilizer and removed the covering from its center section. Using 20-minute epoxy, I set the stabilizer back into place, cleaned off the excess epoxy and rechecked the alignment. Once the epoxy had hardened, I attached the fin using the same process, making sure that it was at 90 degrees to the stabilizer. With the tail feathers installed, I moved on to installing the engine.

* Engine and cowl. I installed a Fuji BT-5OSA gas engine following the manual's instructions for that type of engine It was easy: cut out the mount pattern, line it up with the scribe marks on the firewall and tape it down. Drill the holes where indicated and mount the engine. I did eat up some time installing a bellcrank for the throttle, but the newer Fuji-BT-50SB engines have the throttle arm in a better position on the carburetor that allows a straight shot on the pushrod. No matter which type of engine you use, don't use a metal pushrod for the link to the servo.

Mounting the cowl was next; the plywood-cowl-ring mounting system really makes for a slick installation. Screw the ring to the fuselage with five 4-40 bolts, slip the cowl over the ring, and line it up with the fuselage and the spinner. When I was satisfied with the alignment, I put six large drops of epoxy around the ring where it meets the cowl. After the epoxy had hardened, I removed the cowl and reinforced the joint with epoxy, microballoons and fiberglass strips. The cowl is attached with five bolts from the inside-a nice, clean installation. The plywood ring also greatly strengthens the cowl. Great Planes includes an extended hex wrench for cowl removal-a nice touch.

Next, I attached the landing gear and wheel pants: I screwed on the landing gear, fastened the gear fairings and mounted the wheel pants. To bulletproof your wheel pants, buy a 13x 3/8-inch swatch of Dave Brown Carbon Fiber Tape, and epoxy it to their insides. 1 highly recommend that you take the time to do this. You'll be very glad that you didn't skip this step.