In the December 2012 issue of MAN, our Scale Special issue, Sal Iasilli reported on his amazing giant scale Fieseler Storch build from the Vogelsang Aeroscale kit. Sal too many more photos than could be used in the print article so we’ve included there here in this exclusive online article. Here’s Sal’s complete text, photos and video.
The Fieseler Storch was designed in 1935 and was the most advanced short takeoff and landing aircraft of its time. It servedGermanyin WW II from North Africato the frozen Tundra of Russia. It provided reconnaissance, transportation for high officials and also served as an ambulance. There is an ongoing trend throughout the world now as people are restoring wartime Fieseler Storches to flying condition. Kermit Weeks of Fantasy of Flight regularly flies his Storch at his museum inFlorida, and the Collings Foundation inNew Englandregularly flies theirs at air shows throughout the northeast. There is also a company inColumbiacalled Cricket Aviation that now makes a 3/4 scale replica (the size of a J-3 Cub).
When I learned that Vogelsang-Aeroscale (Vogelsang-Aeroscale.com) was importing a 1/4 scale Fieseler Storch, I was happy to find they had several kits still available. After reading all the literature and visiting the designer and manufacturer’s website (paoloseverin.it), I decided to order one. Paulo Severin, the kit designer, lives in northernItalyand is a highly regarded model designer/manufacturer throughoutEurope.
The kit features the following:
- Brazed stainless steel tubes epoxy powder painted fuselage;
- Streamlined scale struts;
- Functional undercarriage and tail wheel;
- Undercarriage aluminum pants;
- Functional door;
- Motor mount structure;
- Fiberglass detailed cowling with accessories and stainless steel laser cut supports;
- Fiberglass slats;
- Complete preformed and vacu-formed windows with aluminum laser cut frames and 500 scale rivets;
- Inflatable scale wheels;
- CNC cut ribs and all plywood parts;
- All balsa sheets and block;
- Cedar and Obeche spars;
- Balsa/fiberglass special spars;
- Scale aileron and flap hinges;
- Carbon fiber tubes;
- Rolled color plans;
- Mounting photo album; and
- Screws and laser cut stainless steel accessories.
Scale – 1:4
Wingspan – 139.4”
Length – 94.4”
Weight – 25.5 + (Reviewed Model – 32 lbs.)
Engine – 50 cc
Cost: $4,295 plus shipping.
What distinguishes this kit from any other is the magnificent, pre-built stainless steel tube fuselage. It is replicated directly from the factory drawings fromGermany. Every detail that is on the full scale is here. The plans are multicolored and huge and took up one wall of my workshop.
I started by mounting the shock-absorbing landing gear to the fuselage so it would have some stability while I was working on it. I epoxyed the firewall to the fuselage main frame and sheeted the rear cowling with 1/32 plywood. All areas of the steel to wood were roughed up with some 120 grit paper for better adhesion. I next mounted the steel engine mount to the fuselage which gets bolted to the opposite side of the firewall. I then epoxyed the mating wing roots to the upper cabin along with the upper cabin cross members.
I installed the shock-absorbing tail wheel assembly along with the adjustable elevator yoke and epoxyed the two 1/32 plywood side elevator yoke supports. Next, I epoxyed the five CNC cut light plywood ribs onto the metal fuselage fin posts and sheeted the outer framework with 3/32 balsa.
I assembled the rudder ribs onto two carbon fiber rods along with the light ply outer frame then sheeted the trailing edge and base of the rudder with 3/32 balsa. The two carbon fiber rods act as an alignment tool when assembling the rudder. I virtually built the rudder completely in my hand without the use of pins to the board. I then epoxyed the hinge tube to the leading edge of the rudder post and added the balsa half-round leading edge and sanded to shape. The standoff hinges that attach the rudder to the fin post must be aligned properly to the rudder tube which in turn accepts a metal rod that enters the base of the rudder. This took quite a bit of time to align since the upper standoff was slightly larger than the lower hinge standoff. I contacted the manufacturer regarding this minor error and was assured that future kits will be all properly aligned.
The stab and elevator are built in the same manner as the rudder with carbon fiber tubes used for aligning the ribs with the exception that the carbon fiber tubes are removed after the assembly is complete.
I started the wing construction by first pinning the two lower wing spars to the plans and building board and fitted all the ribs to the two spars. Seven of the main ribs have slots cut into their frontal part. These seven ribs support the slat standoffs when the wing is completed. The seven slotted ribs also get both sides laminated to form a pocket to support the slat standoffs. Once the ribs were all lined up to the plans, I C/A’d them to the lower spars. I then fitted the upper spars and also C/A’d them in place. Next, I glued in place the 1/8 light ply sheer webbing to the front and rear spars as shown on the plans. The trailing edge was then added to the wing assembly along with the nose spar. The wing was then removed from the plans and building board and inspected for alignment. I then installed the two steel wing mounting plates to the inner hardwood spars and fitted them to the fuselage mounting studs. The steel wing strut mounting lugs were also installed at this point.
Next, I installed the Fowler hinges for the ailerons and flaps. The wing was then sheeted with 3/32 balsa sheets and the wing caps were glued in place. I temporarily installed the seven 1/8 inch plywood slat supports into the wing leading edge slots. I then aligned the fiberglass slats to the seven supports and held them in place with some masking tape. The positions of the slat supports were then marked with a felt marking pen. The tape and slats were removed from the wing and a grinding bit from my Dremel used to roughen up the marked surfaces to ensure a secure bond. The flaps and ailerons were built in the same manner over the plans as the main wing panels.
I installed the two aileron and flap servos in the wings as shown on the plans. I used Hitec high torque HS645MG servos and installed the light ply servo access hatches.
The rudder uses a pull/pull cable system and the elevator uses a carbon fiber pushrod. I used high torque HS755MG servos for this application.
Next, I fitted the engine to the pre-built engine mount. This required quite a bit of modification. The kit was originally designed for a Laser 300 4-stroke engine. My intended engine was the DA50. To completely enclose the engine cylinder in the cowl, I had to move the engine much further back than called for on the plans. This also required me to have the engine prop shaft extended by an inch and a half. This was done by Sierra Retracts. I also had a complex problem installing the muffler. The cowl is very narrow on the Storch. So, I had to make a mockup custom muffler to fit in the tight confines of the cowl.
I sent the mockup to JTEC Radiowave, and they did an excellent job replicating my mockup. There was very little room for error to make this muffler fit. The fiberglass cowl was then fitted to the mounting brackets. (The engine throttle servo is also mounted alongside the rear firewall in the cowl.) A 24-ounce circular fuel tank fit nicely between the steel engine mount frame. I made a platform on top of the rear engine mount where I fitted two A123 2300mah battery packs along with the DA ignition module. This helps in the balancing of the model by keeping everything as far forward as possible. A third A123 2300mah battery pack for the ignition system was mounted just behind the rear firewall. I gain access to my switches and fuel fill with two scale hatches just behind the cowl.
Covering and Finishing –
The entire model was covered with Solartex. To adhere the Solartex to the metal framework, I used the same procedure as is used for the full scale. I used a product called Poly-Tak Fabric Cement distributed by BalsaUSA. I brushed on a very light coat where I wanted the fabric to adhere to the framework. Normally, on the full scale, they put the fabric on while the Poly-Tak is still wet. Since Solartex has its own adhesion, I let the Poly-Tak completely dry and then ironed the Solartex on as I would normally do for a wood structure. The Poly-Tak is only used to ensure a good bond to the metal. This worked out very well. Once the model was completely covered, I started the tedious task of applying ribstitching and pinking tape. The pinking tape I used was from Get Stenciled. It’s called, “Pink It”. It is made from Solartex. So, it easily irons on and is the same texture as the covering. All the cabin glazing was installed after the fabric covering was completed.
The model was completely painted with white satin Rustoleum enamel. All metal and fiberglass parts were primed prior to painting with Rustoleum auto primer. I wanted something different in the color scheme. That was why I decided on the white ambulance version of the Fieseler Storch. I found a fellow that makes decals for plastic models on the internet named Mike Grant fromCanada. He had the complete artwork he had made up for the Fieseler Storch ambulance version. The artwork was in 1/32 scale, his maximum size. However, he no longer makes the decals but was kind enough to email me his original artwork. The artwork was forwarded to Callie Graphics inNew Mexicoand was enlarged to quarter scale. The finished result was excellent.
Pre-Flight Setup –
The radio used is the JR 12X along with the AR9100 receiver. Since the DA50 engine is much lighter than the Laser 300 that the designer used, I had to and a pound and a half of lead in the nose to correctly balance the model. The ailerons were set with differential – 45 degrees up and 30 degrees down along with 60 per cent exponential. The elevator does not require much movement. I set it at 25 degrees up and 25 degrees down with 60 per cent exponential. The rudder is 45 degrees to the right and left. I used 40 per cent aileron to rudder mix.
Flying – Due to the high winds in the Northeast, my test flying had been delayed many, many weeks. When I finally got a break in the weather, I headed out to my club’s (Skyhawks) magnificent flying field. The wind was coming directly down the runway. I started the engine and checked the throttle for high and low response and all was well. I also did a range check with the engine at high speed. The Storch was positioned straight down the runway and once I gave it power, it started to veer to the right. When I tried to correct it with left rudder, for some reason it continued to the right. Fortunately, I gave enough ailerons to correct the inexplicable condition. When I got to altitude, I kept telling my flying buddy that something was not right and the flying characteristics felt very strange. After a few minutes, I landed to check it out. When I tried to taxi back to the pit area, I had a problem directing the plane. I decided to shut the engine down and walk the plane back myself. When I got the model to the pit area and checked the controls, I was mortified to find that my rudder was working in reverse! I don’t know how this happened, but I was trying to program an on/off switch for my mixing on aileron/rudder and somehow the rudder reversed. I still can’t figure out what caused this. That explained the crazy takeoff and strangeness of the maiden flight. Once this was corrected, the second flight was magnificent. The Fieseler Storch took off straight as an arrow in less than six feet and climbed into the wind at an astonishing 45-degree angle without flaps and at less than half throttle just as I have witnessed the full scale fly. The control response was flawless. After a few minutes of flight time, I had the confidence to do some low, slow flybys for the photographer, Lou Cetrangelo. I was amazed, as were the spectators, at how slow this model can fly without falling out of the sky. I also performed some 60-degree bank circles. Landing was awesome. Into the slight headwind, the Fieseler Storch looked like it was flying in slow motion as it gently touched down. This model is the closest you will ever get to flying the full scale Storch. I love it!