Sikorsky R4 ‘Eggbeater’ Helicopters: A Long Journey
It seems that transport helicopters have progressed greatly in the past 80 years since the days of the Sikorsky R4 “Egg Beater,” which took to the sies in World wᴀʀ…
It seems that transport helicopters have progressed greatly in the past 80 years since the days of the Sikorsky R4 “Egg Beater,” which took to the sies in World wᴀʀ…