22 April

The 1st Air Commando Group using Sikorsky R-4 helicopters stage the first use of helicopters in combat with combat search and rescue operations in the China Burma India Theater.

The Sikorsky R-4 was a two-seat helicopter designed by Igor Sikorsky with a single, three-bladed main rotor and powered by a radial engine. The R-4 was the world’s first large-scale mass-produced helicopter and the first helicopter used by the United States Army Air Forces, Navy, Coast Guard, and the United Kingdom’s Royal Air Force and Royal Navy.