What kind of aircraft was developed by Igor Sikorsky in the United States in 1942?

The story behind the answer

Helicopter is correct. In 1942, Igor Sikorsky introduced the Sikorsky R-4, the first practical, mass-produced helicopter. Unlike jets, blimps, or space capsules, helicopters use a main rotor and a tail rotor to counter torque, allowing vertical takeoff, hovering, and precise landings in tight spaces.

A Russian-born engineer who emigrated to the U.S., Sikorsky had proven the concept with his VS-300 (1939–40). The R-4 brought it to service in World War II, where it was used by U.S. forces and the RAF for reconnaissance and lifesaving rescues. Memory tip: S for Sikorsky, S for Spinning rotor—think helicopter.