Airshow Models 1/32 Christen Eagle II By Ernest Thomas

History

To give the complete history of the Christen Eagle, we have to start with Curtis Pitts. In 1945 Curtis Pitts designed and built a cute little single place biplane that became the prototype (Number 1) for the Pitts Special. The Pitts Special reigned supreme as the ultimate acrobatic biplane for the next thirty years. In the hands of such Airshow legends as Betty Skelton in her Number 2 'Little Stinker', Caro Bayley, Joyce Cates, Charlie Hillard, Gene Soucy, Bob Herendeen, Art Scholl, and Tom Poberenzy, the single place Pitts S-1 was the aircraft to beat on the competition aerobatics circuit. More championship titles have been won in the Pitts than any other design.

Until the 1960s, the accepted method of learning advanced aerobatics was to talk about the maneuvers on the ground with an instructor and then go up and practice solo until it looked right. This method was a waste of time, fuel and money. What was needed was a two place aircraft capable of performing advanced aerobatics. Curtis Pitts already had a two place version of the Pitts on the back burner. In 1965, the two place Pitts was moved to the front burner and made its first test flight in 1966. This two place was dubbed the S-2A and carried the nickname 'Big Stinker'. It eventually earned FAA certification which allowed Pitts to sell the S-2A as a factory built aircraft. (Until the late 70s most of the S-1s were homebuilt.)

In the mid '70s, Frank Christen, who made his fortune in computers, tried unsuccessfully to buy the license and type certificates for the Pitts Specials. So Christen instead bought an S-2A and gave it to an engineer with instructions to improve it. The result was then dubbed the Christen Eagle.

The Eagle featured a roomier, more comfortable cockpit (Christen is very tall), increased area on the rudder and elevators for improved control, a spring type landing gear instead of the Pitts style bungee gear, and a fiberglass cowl. Additionally, Christen hired a graphic designer to create a dazzling color scheme for the Eagle. So the Eagle is essentially a clone of the Pitts S-2A. A more appropriate name might have been Grand Larceny. But the improved clone surpassed the original Pitts design in performance, along with a paint scheme that pilots lusted after. In addition, Christen packaged the Eagle as a homebuilt kit that was, and still may be, the most complete kit aircraft on the market with an extremely user friendly, comprehensive, four foot tall stack of builder's manuals that are still considered the best around.

The Kit

Airshow Models has produced a short run resin model of the Eagle II consisting of 17 resin parts, seven white metal, 10 cast brass, two vac formed canopies, a fret of photo-etched parts, decals for two color schemes (the original Eagle scheme with the full feathers and the tapered feather scheme) and a full color instruction sheet.

The resin parts are cast in a medium gray resin that has a slightly rough texture, similar to a 600 grit sandpaper. This rough texture vanishes after the first coat of primer with a light sanding. At first glance, I thought the cast brass was a bit of overkill. But as I assembled the resin parts, I realized that this is a heavy model and white metal may not have been strong enough to support the weight.

The fret of photo-etch contains the rigging wires, control linkages, canopy release handles and javelin struts. The decal sheets are gorgeous. Very crisp printing with bright, intense colors.

The Build

The first thing on my agenda was to collect references. I was very fortunate to know someone locally who was at the painting stage on an Eagle project. So I was able to make several trips to the local airport and take plenty of photos, not to mention getting enlisted to help out with the masking and sanding work, and thereby earning a ride or two when the airplane is completed. How many of us get that lucky?

After cutting away the pour blocks, I gave the resin parts a bath in warm soapy water to remove any mold release. I then began the main assembly. The first bump I ran into was a bit of asymmetry on the fuselage at the firewall. This was corrected by building up that area with plastic card and sanding to the proper shape. This turned out to be easier than I anticipated.

The second bump was a gap between the bottom wing roots and the fuselage. My first instinctive reaction was to close the gap by just flexing the wing panels up to close the gap, which would have produced a nice dihedral in the bottom wing. Since I was able to study the build manual for the real airplane, I learned that the lower wing has just 1* of dihedral (another deviation from the S-2A). This is barely noticeable - unless it's not there. So I filled the gap with more plastic card.

I then proceeded to attach the cowl, landing gear and tail feathers. The tail feathers went on without a hitch but the brass landing gear struts had a slight bend, causing me to try and put them on upside down. Then the one piece wheel/wheel pant wouldn't fit. Another trip to the airport got me straight on this and I straightened out the gear struts and got it all assembled correctly.

I then primed everything with white primer and proceeded to the cockpit. The kit supplied parts include the two seats, joysticks, instrument panel, throttle quadrants and canopy releases, with some detail molded into the floor. What's lacking is the steel tube structure on the sidewalls, rudder pedals, and the fuel tank which is visible below and behind the instrument panel.

The kit instructions say to paint the entire cockpit black, though the color photo on the instructions show black sidewalls with a white floor. I know for a fact that the real Eagle kit comes with black rubber floor mats. But all this black would make for a very large black hole on the model. Since this is such a large scale model and the bubble canopy shows so much, I decided to paint the side walls white (same as the full size specimen I had for a reference) and add all the steel tube structure. The tubing was made from brass rod painted black. I also added the oil breather line on the starboard side of the cockpit, a fuel tank facade from plastic card and some wire bits meant to resemble the rudder pedals for the front seat. The pedals for the pilot (rear) are so far under the front seat that they're hardly visible on the real aircraft. So I omitted them on the model.

The kit supplied throttles and canopy release didn't really look very much like the those parts on the full size aircraft that I used for a reference. So I scratch-built these parts with sheet styrene, bits of copper foil for the lever arms, topped with a drop of white glue for the knobs. On the rear throttle, I used photo-etched nuts and washers from Copper State Models and bits of wire to represent the circuit breakers and toggle switch that appear on the throttle on the real airplane.

One detail that was missing from the kit was the Christen 844 Fuel Pump, which is a very prominent feature on the floor of the rear cockpit. I scratch-built this from a hunk of round sprue from a plastic kit turned down in the Dremel tool, along with bits of plastic card, rod, strip, more PE nuts from Copper State, bits of brass wire, all topped off with a little blob of white glue for the knob on top of the pump lever.

For the instrument panel, I cleaned up the kit supplied resin panel, which comes with the instrument faces already drilled out. I applied the instrument decal to a piece of plastic card and then glued this to the back of the resin panel, already painted black. The final detail was to fill the instrument faces with Future to give the appearance of glass.

The only things left were the seats and sticks. The seats are molded with the cushion/ parachute and harness and it looked good enough for me. The seats in the full size aircraft are made from white plastic/fiberglass shells, supported by a steel frame which is part of the pre-welded fuselage structure. The aircraft I used for a reference will have seat pack parachutes but as of this writing, those are still not in place so I have no idea what they look like. I painted my seat cushions black with red stripes (molded in) with dark gray harness and silver hardware. There's a radio/transponder stack molded into the back of the front seat, which I also painted black with gray details. There's also a fire extinguisher next to the radio stack, which I painted red. The reference aircraft doesn't have the fire extinguisher.

I feel I must add a few words about all the colors I chose for this project. This is a homebuilt civil/sport aircraft, not some military job painted to spec. Yes, the pre-welded fuselage structure comes painted black but there's nothing to prevent the home-builder from painting it some other color. So I can say with absolute authority that the model builder is free to paint his cockpit (and exterior) any colors he chooses and there isn't an IPMS judge alive who can say it's wrong.

Finally there were the joysticks. The kit supplied brass sticks have a little bit of flash where the mold separated. I figured I could bend new sticks from wire quicker and easier than sanding the kit sticks so that's what I did. A couple of wire rings were added to represent the grips. The last details were the cockpit placards, which are supplied as decals. On the full size aircraft, these placards are white lettering on a black background. The kit decals are white without the black background. The instructions show the "EXPERIMENTAL" placards on the black sidewalls. Since my sidewalls are white, I applied them on the instrument panel and rear head rest/luggage door. The canopy release placards were applied over a little square of black decal film. And that finishes the cockpit.

With the cockpit finished, I felt I was on the home stretch and just about ready for painting and decals. Then I hit the proverbial brick wall. You know, the one that brings the project to a screeching halt and causes it to sit unfinished on the bench for 9 months or longer. On this model, it was the canopy. And it's only fitting that it was the canopy, as the guy who's building the full size Eagle that I used for a reference said the canopy on the real airplane was the hardest part of his project.

Here's the problem with the vac formed canopy on the Airshow Models Christen Eagle: First of all, starting about midway and going back, there's no clear demarcation line where the bubble stops and the canopy skirt starts. This makes masking the bubble an exercise in trying to just eyeball it. And then it probably wouldn't look very good. But an even bigger problem is that the vac formed canopy is too small. On the real aircraft, the canopy overlaps the edges of the cockpit opening by an inch or two in front and back, and about three inches on the sides. The kit canopy only just fits into the opening, with a very slight gap in the front or rear depending on how one positions it. And yes, my Eagle model sat on the bench for about nine months while I thought of how I might correct this.

I first tried gluing pieces of .01x.02 Evergreen strip around the edges and sanding them smooth to blend in. I almost had it perfect until I noticed a hairline crack on the rear edge. I tried to give just a few gentle licks with the fine sandpaper, and broke the Evergreen strip off. But even if I hadn't done that, I still would have had the problem of the no clear demarcation line where the bubble meets the skirt.

In the end, I went to the airport with a dress makers tape rule and took a bunch of measurements on the full size canopy skirt. I then drew a full scale pattern for a new skirt on Autocad, scaled it down to 1/32 and printed out a paper pattern which I then transferred onto .01 Evergreen sheet styrene. I then glued this to the vac canopy. It worked out great but due to the odd shape, the new skirt had to be made in two pieces. The pattern I made had one piece for the sides and back with the second piece for the front. This left the seams to be filled and sanded right on a severe curve. Hindsight being 20/20, next time I'll have the sides attached to the front and let the seams fall where the sides meet the part of the skirt that arches over the top in the rear.

After the new skirt was finally finished, I was ready to start painting.

With such great decals supplied with the kit, all I had to do was paint everything white. I started with a second coat of white primer, sanded with 1000 grit sanding film. I then sprayed three coats of flat white, sanding in between coats with the 1000 grit film. I chose flat white because I just seem to have more luck shooting a nice smooth coat with flats. I always have trouble with glossy paints. After letting the final sanded coat dry for several days, I applied two or three coats of Future to the entire model. Then it was time for decals and final assembly.

Before I could apply the decals, I had to attach the canopy. I first bent a piece of brass rod for the steel frame that the canopy and skirt is built on. Instead of trying to attach this to the canopy, I glued it to the fuselage so I knew it would fit in the opening properly. I then attached the canopy cross brace to the brass rod frame. Finally, the canopy was attached. Doing it this way was a lot easier than trying to attach these parts to the underside of the canopy and insured the proper fit and look when it was all assembled.

Then it was time for the decals. I chose the tapered feather scheme for this project because I have a second Eagle kit that will be finished as the real aircraft I got to use for a reference. This second model will be finished in the original full feather scheme.

The decals on the wings and tail planes went on with no problems at all. They're very large decals so you'll need to keep them plenty wet while moving them into position, but if you do that, you'll have no problems. The fuselage decals were a bit more fiddly. Mainly, getting the top blue stripe to go over the tail plane while the rest go under took some doing. I cut away some of the clear carrier film and managed to get the starboard side decal on in one piece. The port side ended up tearing but that only made things a bit easier.

The area around the canopy took some work. Several applications of Solv-A-Set made the decals snuggle down around the canopy skirt only so far. In the end, I had to cut the decal along the edge of the skirt and then try and mix up some purple paint to match the decal where the white base color showed through. Mixing colors was never my strong suit but I got something close enough to fill in the area that's in the shadow of the skirt edge.

With all of the decaling done, I was finally ready for the final assembly. I first drilled a small hole on the port side of the fuselage below the tail plane and inserted a short length of hypodermic tubing to represent the oil breather line and while I was there, I also installed the photo-etched rudder control linkages. I also added a fuel fill cap made from two small stacked disks cut from .01 styrene. The single I-struts and very rigid cabane assemble make this one of the easiest top wings you'll ever find on a biplane model. It only has three connection points. The white metal and brass cabane structure does require some filling and sanding but it's a good, solid metal assembly and not really much of a challenge. So after the top wing was in place, I added the aileron slave struts, which I made from brass Strutz (brass rod with an airfoil cross section). The kit supplies two pieces of airfoil section plastic rod but I had the brass on the bench so why not use it.

Rigging

The rigging for this model is also as simple as can be. Airshow Models provides all the rigging on the photo-etch fret and it's a good representation of the streamlined cross section tie-rods found on the real airplane. The tail rigging was anti-climatic. The doubled up flying and landing wires are made with a small cross plate at one end and a little bridge connecting the two wires about mid point. The little connecting bridges not only to keep the wires spaced properly, they also indicate where the photo-etch javelin struts attach. If using the PE javelin struts, these must be placed on the rigging wires before the rigging is attached.

I didn't like the flat look of the PE javelin struts so I made new ones from brass rod, using the PE struts as a template for the length and spacing of the notches for the rigging wires. It took a few tries before I got the angles of the notches right but once I had it close enough, the javelin struts fit right into place and were attached with white glue, which I also used to fill in the notches after the struts were attached. I added more PE nuts from Copper State Models to the little mounting plates on the rigging wires. I then added the PE aileron control linkages.

The only thing left was the prop and pitot tube and it was one more model for the shelf.

Conclusion

Except for the trouble with the canopy, this model is about as easy a build as you'll ever find. Especially in a short run resin. There just isn't that many parts.

In addition to adding detail to the cockpit, there are some opportunities for those with AMS to improve things a bit: the inspection covers on the undersides of the wings were omitted. I had meant to add this detail but after having the model sit on the bench for nine months while I hemmed and hawed over the canopy, I forgot to put them on once I got my momentum back. I will add them on the next one and they'll be made from disks punched from copper foil. Also on the next one, I will do a full sheet metal job on the forward fuselage.

On the real aircraft, the fabric on the fuselage ends at the rear of the cockpit and sheet metal panels cover the entire front section. These panels have hard corners bent in them that follow the lines of the fuselage stringers. The model doesn't have these hard corners on the sheet metal panels, instead having a rounded look. And for those who are really cursed with AMS, those sheet metal panels are held in place with hundreds of little sheet metal screws and washers. There was some effort by Airshow Models to represent all these screws but those were recessed into the fuselage and ended up being rendered invisible after all the primer, paint, clear coat and decals.

I did not keep track of the hours spent building this model. It did take about a year but if you subtract the nine months it sat idle, and factor in real life, it was a pretty quick build.

If one were to build it straight out of the box with no mods at all, it could easily be finished in a week of evenings. And the end result is a lovely and extremely colorful biplane on the shelf.