H34 Choctaw

Subject:
RCAF Sikorsky
H-34A Choctaw
Kit Used: Italeri 1/72

Review & model by:
Steve Freeman
Pictures: R. Forys

March 2003
Model of the Month

[The Italeri UH-34D with a Canadian twist.]

History: The Sikorsky model S-58 was conceived in 1952 from a US Navy requirement for an anti-submarine helicopter with greater power and range than the Sikorsky HO4S-1 (H-19). The S-58 won the competition when it's only rival, the Bell HSL-1, failed to meet the performance requirements.

The Navy ordered the helicopter under the designation HSS-1 Seabat. The Marines followed with an order under the designation HUS-1 Sea Horse. The US Army and Air force matched the Sikorsky against the Piasecki H-21. The S-58 lost the competition, but Air Force orders had consumed Piasecki's production capacity, making it impossible to fill an order for the Army. This forced the Army to place an order with Sikorsky under the designation H-34A Choctaw. For an aircraft that wasn't anyone's first choice, three companies, Sikorsky, Sud Est, and Westland, produced 2,351 units in three countries, US, France, and England, over a 25 year period.

Canadian Service Canada was the second foreign purchaser (after France) of the H-34. The Royal Canadian Air Force purchased six "A" models in 1955 to support construction of the Mid-Canada Line early warning defense system. After completing that task they served with various units across the country in SAR, cargo, personnel transport, and training roles. The surviving aircraft retired in 1971. The subject modeled here represents an aircraft half way through its RCAF career (circa early '60s). It is based on a picture of a SAR marked machine performing a re-supply mission to a forest fire fighting base camp near Sioux Lookout in Northern Ontario. The exact unit that the aircraft belonged to at the time is unknown. Given the location of the base camp, it was probably from the 111th Communications Unit out of RCAF Base Winnipeg.

The Kit: The model was built using the 1/72 scale Italeri UH-34D Sea Horse (kit #066) as the basis. The Cobra CH-34D/G Cockpit and Cabin detail set (kit # CC72002), the Eduard UH-34D Sea Horse detail set, and the radial engine components from an 1/72 scale Esci M4A1 Sherman tank were used to expand the level of detail. The Italeri kit is well molded with fine details and engraved panel lines. The level of detail in the interior and on the drooping rotors would make this kit a nice model out of the box. The only construction problems I had were self inflicted.

In preparation for the addition of details I removed the cooling grills around the nose and the extension of the fuselage bottom that covers the oil cooler bay. As the moldings are thin, I reinforced the main fuselage seams with plastic strips. The basic interior structure was built using the Cobra detail set. I had to test fit and file the vertical bulkheads at both ends of the main cabin to get the fuselage halves to close properly. The instrument panel and cockpit/main cabin seats were supplied by Eduard, Cobra, and the base kit, but ultimately, the Eduard pieces were used. Masking tape seat belts for the troop seats completed the interior.

The engine bay bulkheads and framing were scratch built. I didn't quite get their shape right, and I had to fiddle with the seam when I glued the nose pieces to the fuselage. (I glued the nose sections to their respective fuselage halves first, then to each other. That way I only had one seam to rework.) A hole was cut into the bulkhead that forms the forward edge of the clutch compartment (visible through the cooling grills). The Esci Sherman radial engine, mountings, and cooling fan were assembled and a clutch fairing and drive shaft were added. When installed on the bulk head, you can see the drive shaft and fan through the grill, and the engine through the bottom of the nose cowlings. To represent the exhaust system used on the "A" model, thin diameter solder was run from each cylinder to the point where the exhaust exits the nose. After tacking them together with a little superglue, the assembly was removed and gently heated and formed into a single unit of ever expanding size. It was completed by attaching the end of the kit exhaust to the assembly, and gluing it back on to the engine. I then added an oil cooler, accessory boxes, and various hydraulic lines to complete the engine bay detail.

The Eduard framework that supports the main rotor seemed a little flimsy for my taste, so the rotor mast support from an Italeri H-19 was borrowed, and a resin copy was cast. A hole was drilled in the support to take the rotor shaft where it was mounted to the kit. This successfully took the stress off of the brass frame work. The last modification made was to open the side windows. The side window frames were cut out of the fuselage parts, and square stock was added around the side window clear pieces to replace what was removed. When painting was complete, the side windows were attached in the open position. Construction was finished by adding the small details from the Eduard set to the fuselage, rotors, undercarriage and doors.

Maybe the biggest problem occurred when the tail wheel strut broke off during painting. The original strut would not reattach strongly enough to support the weight of the model, so a new strut was constructed out of brass rod.

Finishing: The aircraft was finished in the standard red over blue with white cheat lines applied to all RCAF helicopters of the era. Eduard H-34 Express Masks (# XS085) were applied to windows and the whole airframe was sprayed flat white. The day glow orange tail band was than masked and sprayed on. The large white band along the fuselage sides and the orange tail band were then masked off, and the upper half of the fuselage was sprayed red and the lower half blue. Note the red and blue colors are not the same as the red and blue in the RCAF insignia. Model Master paints were used in this project, specifically White Primer, Italian Red, and Ford/GM Engine Blue. The majority of the decals are from the Belcher Bits 1/72 scale Canadian Helicopter sheet. The large "RESCUE" markings where taken from an Arrow Graphics sheet. They are supposed to be insignia red but are very translucent. I applied two sets, one over the other, to try to fix this, but without much success.

One other problem I had finishing this kit was that the mesh around the cooling grills filled in with paint restricting what can be seen behind them. In the future, I'll mask off the mesh before I spray, and finish the section by hand with thinned down paint.

Conclusion: Ever since I discovered the Esci Sherman kit many years ago, I thought about building a helicopter around a tank engine. Earlier, I'd used the Esci engine in a simpler modification of the Italeri H-21 kit and decided to tackle the H-34. I had a lot of fun with this project and learned quite a bit. As soon as I recover, I'll tackle a RCN H04S (H-19). Who knows, I may even build one those engineless Shermans some day.

References:
1. High Flight, Vol. 2 No. 4, pages 142 - 152 The Mid-Canada Line
2. Sikorsy H-34 An Illustrated History; Lundh, L., Schiffer Publishing, 1998