Gallery: Sal Calvagna’s Award-winning Sikorsky Bomber
The world’s only RC 1913 Ilya Muromets
The world’s only RC 1913 Ilya Muromets
In the world of RC scale, there are scale projects, and then there are scale projects—those scale airplanes built because they mean something special to the builder. Just such as a project was first unveiled at the 2016 Westchester Radio Aero Modelers (WRAM) Hobby Exposition, designed, built, and ultimately flown by our longtime contributor Sal Calvagna. Sal’s Sikorsky Ilya Muromets is an impressive 1/6-scale model of one of Igor Sikorsky’s early biplane designs. And it is hard to miss as it has a whopping 16-foot wingspan. Sal worked feverishly for about 16 months to finish his monster multiengine biplane, and his efforts impressed the judges, as the Ilya Muromets earned him the coveted Best in Show award. Sal said that he wanted to build the model to honor one of the great aviation minds of the 20th century, Igor Sikorsky. Always thinking outside the box, Sikorsky designed the Ilya Muromets in 1913, and powered by Sunbeam Crusader V-8 engines, it was the world’s first four-engine civil aircraft. Later converted to a heavy bomber for World War I, it first flew in that role in 1915.
Sal’s model has an impressive 194-inch wingspan, and it is powered by four AXI 4130 brushless motors. It is completely detailed inside and out, and most—if not all—of the hardware and attachment brackets are handmade. The model is covered with Solartex and painted with scale-matched latex paint. There are 200 wing ribs, and Sal had his friend Gunny Bumburs at Aviation Concepts laser-cut them. The thicker plywood ribs were CNC machined, and they are the same scale airfoil used on the full-size aircraft, all fitting perfectly into place. For the main spars and for the leading and trailing edges, he used carbonfiber tubes. This allowed the wings to be built with a scale thickness while still maintaining stiffness and rigidity, making the RC model structure practical. The fuselage is almost 10 feet long and is basically a box structure. It has internal detailing for the cabin interior, and the completed model weighs 45 pounds.
When it comes to assembling the gigantic biplane, there are 32 wing struts and 170 turnbuckles to attend to, but this is where all the Ilya’s character comes from. There are no plans for Sal’s model, so he enlarged scale 3-view drawings to get the basic dimensions worked out. As far as anyone can tell, this is the only RC model of the aircraft
in the world. For guidance, Sal uses a 2.4GHZ Futaba 10C transmitter and standard sport servos, with all the control surfaces using pull-pull cable control. The four AXI 4130/20 motors are fed by four Jeti 77 OP speed controls with four 6S 5000mah Turnigy Lipo packs.
To produce the four scale Sunbeam V-8 engines, Sal made wood masters for all the engine parts and then resin-casted the detailed pieces. The engine blocks are made out of light ply, and when assembled, the AXI outrunner motors used for power fit precisely into place. The motors cannot be seen when the scale radiators are installed. For thrust, Sal uses Falcon propellers. The landing gear is scale and completely functional, with bungee suspensions. The wheels are made out of solid 5/4 pine, and Sal finished them so that they look just like the leather-covered dual wheels used on the original.
ON THE CIRCUIT
For the past two years, Sal has been attending several RC events, both flying and in static competition. Here’s the list of awards that Sal has earned with his impressive and unique RC tribute to Sikorsky’s vision of aviation: WRAM 2016, Best in Show Toledo 2016, Second Place, Designer Class Toledo 2016, People’s Choice Toledo 2017, First Place, Designer Class Toledo 2017, Best in Show Sal also commented that he is particularly proud of winning the “Spirit of Rhinebeck” award during the 50th Annual WW I RC Jamboree at the Old Rhinebeck Aerodrome in 2016. This is where the Ilya Muromets went from just a great scale project to a proven RC scale model, as it flew effortlessly from the aerodrome’s runway.
Sal receives the Spirit of Rhinebeck award at the 50th annual WW I RC gathering.
The Ilya Muromets bombers were powered by a myriad of engine types. Sal chose the British Sunbeam Crusader V-8 version of 150hp each. The dummy engines house the electric motors that power the model.
The Ilya Muromets was powered by four engines, all requiring a magneto switch. The leather pouch below stored maps.
True to the full-size version, the 1/6-scale landing gear incorporates a central truck that is wrapped by four sets of bungee cords to provide shock absorption.