McCulloch MC-4

The McCulloch Model MC-4 was an American tandem-rotor helicopter and was the first helicopter developed by McCulloch Aircraft Corporation, a division of McCulloch Motors Corporation.Harding, Stephen ''U.S. Army Aircraft Since 1947'', Airlife Publishing, Ltd. 1990. It was evaluated by the United States Army as the YH-30 and the United States Navy as the XHUM-1.

Design and development

The MC-4 was a larger version of the earlier HERC JOV-3 tandem-rotor helicopter and was developed by the McCulloch Aircraft Corporation. The JOV-3 was developed by Jovanovich when he headed the Helicopter Engineering and Research Corporation. The JOV-3 first flew in 1948. In 1949, Jovanovich moved to the McCulloch Motors Corporation, where an enlarged helicopter, the MC-4, first flew in March 1951. It was followed by a similar MC-4C and three evaluation helicopters for the United States Army (as the YH-30). The MC-4C was slightly larger than the MC-4. When the MC-4C was certified in 1953, it was the first tandem-rotor helicopter to be certified in the United States for commercial use. Three examples were evaluated by the United States Army as the YH-30, but the Army's evaluation showed the helicopter to be underpowered.

The YH-30 had a steel tube framework with a light metal skin, A single 200  hp Franklin piston engine was horizontally mounted amidships and powered two intermeshing tandem rotors. It had a fixed-wheel tricycle landing gear with a castering nosewheel.

No civil or military orders were received and Jovanovich formed his own company, the Jovair Corporation, where he modified the MC-4C as a prototype for a four-seat private helicopter designated the Sedan 4E. The Sedan 4E was powered by a 210 hp Franklin 6A-335 engine. A version with a turbocharged engine was designed as the Sedan 4ES and a more basic Sedan 4A for agricultural use. By 1965 a small number of Sedan helicopters were built. In the early 1970s, McCulloch regained the rights to the helicopter designs.

Variants

; McCulloch MC-4
: Prototype with a 165 hp Franklin engine, two built, one for evaluation by the United States Navy.
; McCulloch MC-4A
: Variant for evaluation by the United States Navy as the XHUM-1, two built.
; McCulloch MC-4C
: Prototype with a 200 hp Franklin engine, one built and an additional three for United States Army evaluation as the YH-30.
; Jovair Sedan 4E
: Production civil four-seat version powered by a 210 hp Franklin 6A-335 engine.
; Jovair Sedan 4ES
: Sedan with a turbocharged 225 hp Franklin engine.
; Jovair Sedan 4A
: Simplified agricultural version.

Military designations

; YH-30
: Military version of the MC-4C, three built.
; CHUM-1
: Two MC-4As for evaluation by the United States Navy, later redesignated HUM-1.

Operators

;
*United States Army
*United States Navy

Surviving aircraft

* 133817 – HUM-1 on static display at the Pima Air and Space Museum in Tucson, Arizona.
* 133818 – HUM-1 on static display at the Yanks Air Museum in Chino, California.
* 52-5837 – YH-30 on static display at the United States Army Aviation Museum at Fort Novosel, Alabama.

Specifications (YH-30)

References

Notes

Bibliography

* John Andrade, U.S.Military Aircraft Designations and Serials since 1909, Midland Counties Publications, 1979, (Page 121)
* The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing, Page 2213/2214.

External links

Jovair history

{{USN helicopters

1950s United States experimental aircraft
Tandem rotor helicopters
1950s United States helicopters
Aircraft first flown in 1948
Single-engined piston helicopters