Historical Snapshot

In 1950, McDonnell Aircraft Corp. began building its second ramjet-powered utility helicopter, called the Model 79. Nicknamed Big Henry, it was based on the McDonnell XH-20 Little Henry of the late 1940s.

The single test model showed satisfactory flight characteristics during testing, but like its smaller predecessor, Big Henry's ramjet engines were too noisy and used too much fuel. It did not attract a buyer, so the project was abandoned.

Technical Specifications

First flight March 26, 1952
Model number 79
Rotor diameter 27 feet
Length 15 feet 6 inches
Height 8 feet 4 inches
Empty weight 647 pounds
Loaded weight 1,800 pounds
Power plant Two 8RJ4 ramjet engines
Speed 86 mph