Robert McCulloch (1911-77) was a Missouri-born businessman most notable for founding the McCulloch Motors Corp., which produced small two-cycle engines that McCulloch used in his own line of chain saws.  The distinctive yellow McCulloch brand of chain saws is one of the most well-known lines of these instruments.

McCulloch’s other ventures included oil and gas, automotive engines, and aviation.  In 1946 he founded the McCulloch Aircraft Corp. which acquired the assets of a firm called Helicopter Engineering Research Corp., consisting mainly of the designs for some small, tandem-rotor utility helicopters and an autogiro.  McCulloch built several variants of the MC-4 helicopter between 1951 and 1957, when the rights to the chopper were sold back to its original designer, Drago Jovanovich.  About a dozen MC-4s were built in total, several being evaluated by the U.S. Army and Navy where they failed to win much support.  Three McCulloch MC-4 specimens are known to survive.

HUM-1, Yanks Air Museum

This is one of two MC-4C aircraft tested by the U.S. Navy, which designated it the HUM-1.  The “HU” stood for “helicopter utility”, the “M” was the McCulloch manufacturer code, and “-1” indicated the first version.  It is preserved at Yanks Air Museum.