Skyshark *** CHRISTEN EAGLE II **
In one of my weak moments I had purchased yet again another biplane. I have always liked bipes, and probably always will. I seem to lean towards areobatic biplanes. My first biplane was a 1/4th scale Super Stearman followed by a Astro-Hog, Waco, another few more Stearman's, then I moved over to aerobatic bipes. Having owned several Model 12 Pitts Monsters, S2S, and other Pitts variations I made a latteral move over to Christen Eagles. My Skyshark Christen Eagle is number three. I have also put a lot of air-miles on an Ultimate, as well as a Ultimate Pitts. In other words, I fly biplanes, lots of them. This is my first SKYSHARK model and I had no idea what to expect. Because there several reviews regarding the packaging, and building of the Skyshark Christen Eagle I thought I'd invest most of my time on the flying aspect. This ARF was a little tougher to build as compared to others I've assembled, but it was worth the trouble.
My purpose here is to inform you what to expect from a hot aerobatic biplane and to compare the Skyshark model in this line-up. First and formost. If you haven't flown biplanes in general and especially short-coupled ones, you may want to re-consider going to a Christen Eagle. Like all hot biplanes, this one requires a lot of high-quality stick time to successfully fly. Don't get me wrong here, Eagles fly great! But in the wrong hands they'll drop out of the sky in a New York second. My point here would be that you have to know and understand precisely how hot bipes fly. All of them (without exception) are hyper-responsive on the controls. Regarding powering a hot bipe, never under-power it. These airplanes depend on prop-wash... LOTS of prop-wash. Always use the upper recommended engine. I generally go one step farther. My Great Planes Eagle is powered with a G62 Zenoah, and my Skyshark Eagle uses a 3MM 53cc. Big engines will get you out of trouble more than they'll get you into trouble. I also don't use dual-rates on hot biplanes. Instead, I use Exponential. You will find your biplane to be much more forgiving especially on take-off & landing. Before I go into Skyshark Eagle mode, I'd like to mention wing incidence & CG. Take whatever time it takes to set these up properly before you even "think" about flying. This will either MAKE or BREAK your hot biplane experience.
OK, it's Skyshark Christen Eagle time. My Skyshark Eagle is powered with a 3MM 53cc gas engine, slinging a 22x8 Zinger prop. It weighs exactly 16 pounds Ready to Fly. My wing incidence is set at -.5 on the bottom, and +.5 on the top. The manual says you need 1 degree difference between top & bottom wing. I adhered to this recommendation! But I also set it up relative to the horizontal stab, which the manual made no reference to. The CG is perfectly neutral. After several tanks of gas being run through the engine, it was time for the maiden. I was a bit concerned about the Skyshark being 99.9% scale. Perfect scale models are typically tougher to handle than a semi-scale models. Not so with the Skyshark Eagle. I fired up the Eagle and let it warm up while checking the controls and range-checking it. I taxied out and tested the ground handling. The Eagle was fine. I lined up heading into the light wind, and checked the controls one last time. It's now do or die. I slowly throttled her up to about 1/3 throttle and let the Eagle gently build up speed. I did have to give it right rudder, but that's perfectly normal. This aircraft can take-off GREEN, so it's imparative to keep it on the ground until it reaches a safe take-off speed. Once it lifted off, I kept it level and gave it more power then began a gentile left-bank. She was smooth and stable. Once I got her going down-wind I checked the controls for trim. It needed some down-elevator but the ailerons were dead-on. After trimming it, I flew the first flight gentile to get familiar with the aircraft. I did basic laps, loops, and rolls for about 10 minutes. Now it was time to land. Heading down-wind, I pulled the throttle back to about 1/4 and gently left-banked while decending towards the runway. Once over the runway, I pulled the throttle down a bit more and the Eagle gentle settled into a tail-high touchdown and rolled about 200 feet. This was a perfect "text-book" landing. The next flight was considerably more aggressive. Once airborne, I began throwing the sticks. My first test was elevator SNAPOUT. Flying level at 1/2 throttle I jerked the elevator full up. The Eagle immediatly snapped to the left. This is preciesly what I had expected and was pleased with it.Next, it was time to try the rudder. Again, flying level at 1/2 throttle I threw the rudder full left. And as expected, it immediatle snapped into a hard left roll-over. I was very happy with this! While still holding full left rudder, I threw in full right aileron. The Eagle immediatly rolled into a slow decent inverted flat-spin. That was such a beautiful maneuver! Upon control release, she came right out. After that, I tried an upright flat-spin. It was smooth, pretty and graceful. It was now time to see if the wing orientation was good, bad, or ugly... Flying 1/2 throttle inverted and level, I put it into a 45 degree inverted climb and let off the controls. Normally, an aircraft would slowly loop down. The Skyshark Eagle looped up. This indicates the incindence is off relative to the thrust-line & horizontal stab. I will have to work on that.
Fitting a 53cc engine in the Eagle was easy. The entire engine fits within the cowling with room to spare. You'll notice there's no stand-offs needed. This is because the Skyshark has an adjustable firewall box. What a great idea! The radio I am using is a Spektrum 2.4 Ghz and I can't say enough good about it. I have never, ever had a single moment of trouble with this radio. All the servos are high-powered digitals and driven with a 5 cell 2500Mah Nickel Metal Hydride battery pack.
Landing the Christen Eagle is straight forward. I like to "tractor" mine in using good throttle management. Basically, all I do is cut the throttle to about 1/2 on the down-wind leg letting it bleed off speed. When I make my final turn I cut the throttle to a fast idle (approx. 1/4 throttle) letting the biplane gently decend over the runway, Once I have the Eagle set where I want it, I slowly pull the throttle down and hold the elevator up slightly. The Eagle sets down gently every time.
The down-side to hot biplanes! Because this is a very short-coupled aircraft it can change course in a flash. From the very moment you throttle up to take-off to the moment you land, you must keep total control of this biplane. Right rudder is manditory for take-off, and the faster you throttle up the more rudder it requires. I attempted a no-rudder take-off and the aircraft made a sudden left turn. I managed to get it flying, but barely. The Eagle is also eager to comply with control input, so it's imparative you plan your inputs. Any sudden change in control can AND will yield a rapid responce. I use exponential on my radio to minimize sudden pressure change. The recovery rate from high G maneuvers is good, but you have to be up high. This is an excellent aircraft if you like throwing your plane around! It's agile and very responsive. It's knife-edge is one of the best I've flown. Forget 3D though. This bird won't do hardly any 3D except for hovering, blender, and a few others. Zero airspeed maneuvers simply won't happen. This isn't a 3D aircraft and shouldn't be flown that way. Cross-wind landing is sort of tricky. It will yaw hard into the wind if you're not careful. From a Scale Model perspective, the Skyshark Christen Eagle II is very accurate. Even the wing plan-form is 100%.
I like this aircraft, but I probably won't fly it every day. Wind direction & conditions will dictate when it gets flown. Overall it's a reasonably well built, and rock-solid airframe. The canopy on my Skyshark is thin and it warps in the heat of the day, especially around the black trim. To date, I only have 7 flights on it so I can't really cover its durability but it appears as though it will hold up to the 53cc engine.
One final note about flying the Eagle... You would "think" that the color scheme would be very visible in the air, NOT SO! The colors just blend in to oblivion. Even my Black base color does this. And with the color scheme on both top & bottom really makes it difficult to tell top from bottom. I removed the bottom feathers and added some bright orange stripes. This cured the problem.
Copyright © 2007 M. B. Fuess