Two different helicopters are tested in flight, climbing and descending by airborne pilots in 1955. (1940s)

Name: Two Different Helicopters Tested Flight Climbing
Uploaded: 2016-09-09T00:00:00.000Z
Duration: 1 min 9 s
Channel: Rick Ray
Description: Two different helicopters are tested in flight, climbing and descending by airborne pilots in 1955. (1940s) Stock Footage Video (100% Royalty-free) 19442770 | Shutterstock