In 1940s Burma, a New Kind of Flying Machine Joined the War: The Helicopter | Air & Space Magazine| Smithsonian Magazine
The First Helicopter Boys: The Early Days of Helicopter Operations - The Malayan Emergency, 1947-1960: Amazon.co.uk: Taylor, David: 9781526754134: Books
When was the 1st helicopter made and used? - Quora
CIA helicopter used in first Afghanistan mission post-9/11 finds home
Helicopter - Wikipedia
Helicopter - Wikipedia
HavKar : When Was The First Helicopter Invented
The First Helicopter Rescue | Defense Media Network
1st AFAMF Hummingbird — China's First Helicopter - Sino Records
Almanac: Father of the helicopter - CBS News
How Sikorsky's first helicopter took flight in CT: Getting There
World's first practical helicopter VS-300 took flight at Stratford on this day in 1939 | Rest of the World News
The Helicopter: A Hundred Years of Hovering | WIRED
Igor Sikorsky Built His First Helicopter Before the Wrights Flew – Disciples of Flight
Who Invented the Helicopter? (and When?) - Aero Corner
14 September 1939 | This Day in Aviation
The first operator: Helicopter Air Transport - Vertical Mag
The U.S. Army's first helicopter - Vertical Mag
When was the first helicopter ever used in combat? - Quora
The First BIG U.S. Helicopter | Naval History Magazine - April 2021 Volume 35, Number 2
World's First Helicopter - Prehistoric - YouTube | First world, Helicopter, Prehistoric
Aviation History - First Helicopter Flight-November 13, 1907 - Flight Journal
Black Hawk helicopter flies for first time without a pilot on board | CNN Politics
Helicopter | Facts, History, & Types | Britannica
Sikorsky R-4 - Wikipedia
World's First Helicopter – Today in History: September 14 - Connecticut History | a CTHumanities Project
The Helicopter: A Hundred Years of Hovering | WIRED
