Special Hobby 1/48 R4B Kit First Look

By Michael Benolkin

First Look

On 13 Jan 1942, the Sikorsky XR-4 took its first flight, becoming what would be the first 'production' helicopter to fly. The Luftwaffe had flown helicopters earlier than this, but none of them had entered 'production' In fact, legendary Luftwaffe Hanna Reisch had flown one of their early helicopters inside the Deutschland Halle (an indoor stadium in Berlin).

Powered by a 185hp Warner R-550 engine, the R-4B would become the production version of the series, with around 131 examples built for the USAAF, USN, USCG and RAF. The R-4B was used primarily as a training and observation aircraft. The fuselage 48 ft 2 in long, sporting a three-bladed main rotor with a diameter of 38 feet. Maximum level speed was 75 MPH, while the R-4B's maximum range was a modest 130 miles. Known to the USAAF as the R-4B, the Sikorsky machine was designated by the Navy and Coast Guard as HNS-1, while the RAF dubbed the aircraft Hoverfly Mk.I.

This is Special Hobby's second 1/48 offering, and this kit is highly detailed! Comprising 50 injection molded plastic parts, 17 polyurethane parts, and 13 photo-etched parts, the H-4B puts a great deal of detail in a small space.

As with most helicopters, the majority of the detail visible is inside the cockpit underneath the greenhouse canopy. The pilots seats come complete with lap belts, and both crew positions have collective and cyclic controls provided. There is even a radio and fire extinguisher mounted on the aft bulkhead.

The engine bay immediately aft of the cockpit is covered with photo-etch grillwork, adding to the level of detail of the kit. While not specified in the instruction, it appears that the best approach here is to paint the blank areas (representing the engine bay) aft of the cockpit flat black prior to installing the photo-etched grills.

Assembly of the landing gear and tail rotor framework will take a bit of engineering and patience to accomplish, but the final result appears to capture the 'fabric-covered' pipe skeleton that these early helicopters were. Additional details are provided to construct the unique tailwheel framework unique to the USN and USCG versions.

This would be the perfect time to break out that pinvise and brass wire. Drilling pin holes into the landing gear frames where they attach to the strut and to the fuselage, as well as drilling corresponding holes in the struts and fuselage will allow you to install short lengths of brass wire to reinforce the framework. The same technique will be required for the tailrotor framework as well.

The main rotor is also a kit unto itself (22 parts), capturing the detail of the swash plate, push rods and rotor head assembly.

The real H-4 was a lightweight aluminum pipe skeleton, the majority of which was covered in fabric. The Special Hobby kit captures the delicate construction of the H-4, and with some variation of the construction techniques suggested above, you can have a solid replica of this unique piece of rotary-winged history.