The helicopter was provided with a new control system, revised instrumentation, and larger fuel tank.
[2] A total of 211 KH-4s were built, including four that were modified from existing Bell 47Gs.
The vast majority of these were bought by civil operators, although some were purchased by the military forces of Japan and Thailand.
[2] Data from Jane's All The World's Aircraft 1966–67[7]General characteristics Performance
Related development Aircraft of comparable role, configuration, and era