GREAT PLANES Christen Eagle II ARF
CLASSIC AEROBATIC BIPLANE
The Christen Eagle II is one of the most popular home-built aircraft ever made. Developed in the late 1970s, the Christen Eagle II set a new standard in excellence for home-built aircraft. Based on the famous Pitts Special designed by Frank Christensen, the Eagle II was designed for unlimited class aerobatic competition, advanced aerobatic training and sport cross-country flying. The Christen Eagle II is a delight to its owners.
When you first open the box, you will see how Great Planes has captured both the looks and quality of this beautiful sport biplane. Its magnificent color scheme will impress you. All of the components are covered with MonoKote, including the feather graphics. As usual, Great Planes includes a complete hardware package for the kit. You will also find an included fiberglass cowl and wheel pants, flying wires and a polished aluminum spinner.
PLANE: Christen Eagle II
Manufacturer: Great Planes Model Mfg.
Distributor: Great Planes Model Distributors
Type: Sport Aerobatic
For: Intermediate to advanced pilot
Wingspan: 68.5 in.
Wing area: 1,436 sq. in.
Weight: 290 oz.
Wing loading: 29 oz./sq. in.
Length: 62.5 in.
Radio: 4-channel with 8 servos; flown with a Futaba 9C transmitter, Futaba FP-R127DF receiver and Hobbico C-65 servos
Engine Range: 1.6 to 2.2 ci 2-stroke, 1.8 to 3.0 ci 4-stroke, 2.0 to 3.2 ci gas; Engine used: Fuji BT 50 gas
PROPELLER/SPINNER: Top Flite 20×8; Spinner include in kitTOP RPM: 7,420
FUEL: Gas and oil mixture as recommended by engine manufacturer
ONBOARD BATTERY: Sanyo 1400mAh NiCd 4.8 volt
Components needed to complete: Radio, servos, engine, prop, fuel tubing, battery servo leads, Y-harnesses and switches (one for radio and kill switch for engine)
Before I go any further, I think I should point out that the full-size CE II is a real hotrod. Keep in mind that the Great Planes Christen Eagle II is designed for a maximum gas engine size of 3.2 ci. I know that we are always tempted to go bigger than recommended—not a good idea for a kit of this scale. You know what will happen: Put an outsized engine in the plane and you won’t be able to resist the temptation to fly the Eagle wide open. And if the airframe fails it will be your loss. So stay within the range suggested by the manufacturer.
The wings are very well prepped for assembly. The top wing is made up of three sections: two outer panels and a center section. Inside each of the outer panels you will find pull strings for the servo wires. Just be careful not to glue the strings when you are joining the three sections. I used PK Industries 30-minute epoxy and alcohol to clean the excess epoxy.
The bottom wing is made up of two panels. Along the same line, take note of the pull strings. All of the hinge locations on the airplane are pre-cut, which saves time. A generous amount of PK Industries Hyper Bond thin CA on each hinge will result in a very strong hinge system. Included in the kit, as with most Great Planes kits, is a better than average hardware package. In this case, most of the hardware is heavy-duty, which is great when using a high output gas engine. Spend a little extra time on the alignment of the wings. It will be worth it in the end. A straight and true plane will always fly better.
The Christen Eagle is designed for several engines, the Fuji 50 being one of them. The engine installation is very simple and the fit is excellent. The only thing you may want to do is to add an extension to the Fuji muffler to get the exhaust out past the bottom of the cowl.
The entire assembly of the Great Planes Christen Eagle is straightforward and as usual, the high quality and well-written instruction manual will make assembly of this beautiful ARF trouble free.
The Fuji ATM (Automatic timing module) is supposed to make this engine start by hand. The first time was somewhat difficult. However, after running the engine for about fifteen minutes and allowing the fuel to get into the engine and lubricate the parts, hand starting was as good as with an electronic system. Two or three flips with the choke on and the engine will pop. Two more hand flips and the Fuji 50 comes to life. After the pre-flight and run up, the Eagle was ready to fly.
|Takeoff— Ground handling is excellent. Just remember to hold in some up elevator while taxiing. With the nose into the wind and a touch of up elevator, the Eagle tracks straight down the runway and as you relax the elevator, the tail comes up and the Eagle is airborne. The Fuji has more than enough power. To my surprise I did not have to add right rudder. The climbout was straight and true. Once leveled out I only needed to add about two clicks of right aileron and the Eagle was trimmed and ready to play.|
General flight handling— With power set at about 70 percent, the Christen Eagle handles very nicely. Both elevator and ailerons are positive and quick to respond. Turns in both directions needed some elevator input to keep the plane level. Stalling the airplane is a bit touchy. As I pulled back the throttle and the plane lowered down, I found that I needed to add a generous amount of elevator. The nose dropped sooner than one would think. It seemed that the stall speed was higher than you would expect. However, the stall was clean and straight. By adding power and slight up elevator, the plane was straight and level once again.
Aerobatics— Now the Christen Eagle comes to life. At full power the rolls to both left and right are straight as an arrow. The Fuji 50 yanks the Eagle up through a loop with authority. Even with a snap at the top of the loop, the controls are clean and crisp. Slow rolls do require some down elevator on the inverted side. Inverted flight also required down elevator input. Knife edge also required a good amount of rudder to keep the nose straight. The plane acts as though it is slightly nose heavy, yet the CG was set at the recommended point as per the instruction manual.
The manual notes that after gaining familiarity with flying the Eagle II, you may experiment by moving the CG forward or aft by as much as 3/4 in. I moved the CG 3/8 in. aft of the recommended starting CG point and found that rudder and elevator inputs provided much more authority in maneuvers where input is needed to keep the nose up. If you want a more responsive ship, I can only advise that you move the CG aft in very small increments. If you back the CG too far aft of the recommended location, the Eagle II will become quite a handful and you would not want to risk such a beautiful plane.
Landings— Biplanes have more drag than their single wing brothers. Therefore, they require a little more power on final approach. With the Christen Eagle lined up on final, it settled in very nicely. However, when I went to flare for landing, the plane seemed to run out of elevator response somewhat early. Be ready and close to the ground. This can be remedied by moving the CG slightly aft.
This is another winner from Great Planes. I was impressed with the Eagle’s looks, construction and quality. The hardware is of high quality and the engine I installed, the Fuji 50, is a perfect match to the airframe. I found the recommended CG to be a little forward for my aggressive flying style, but after moving it back by 3/8 in., the airplane flies extremely well. The Great Planes Christen Eagle II is a welcome addition to my hangar.
The Great Planes Christen Eagle is one of the best looking planes to come to market in a long time. The 1/3 scale is big, but not too big to transport to the field. I was impressed with its looks, construction and quality. Flight characteristics were quite good and, if you prefer a very responsive aerobatic airplane, can be improved through careful experimentation with a slightly more aft CG. After many flights and some CG adjustments, I have the ship set up to fly exactly the way I want it to. There’s no doubt, this is a great looking and great flying model.
Great Planes Model Manufacturing
distributed exclusively by Great Planes Model Distributors