World's First Manned Electric Helicopter Takes Flight!
Sioux Helicopter – Warlord Games Ltd
Rotorcraft manufacturers celebrate anniversaries | AirMed&Rescue
Helicopter | Facts, History, & Types | Britannica
The Helicopter as a Combat Platform - Indian Defence Review
Which was the first military helicopter of the world? What was the purpose of inducting a helicopter in military aviation? - Quora
VFS - January 2019
World's First Helicopter - A History of the Helicopter | Engre
Why did the half-plane, half-helicopter not work? - BBC News
World's First Helicopter - Prehistoric - YouTube
The Helicopter: A Hundred Years of Hovering | WIRED
Helicopter | Facts, History, & Types | Britannica
Paul Cornu's “flying bicycle”: the 110th anniversary of the first helicopter flight | World Air Sports Federation
The World Encyclopedia of Military Helicopters: Featuring Over 80 Helicopters with 500 Historical and Modern Photographs: A Complete Reference Guide ... With 520 Historical and Modern Photographs: Amazon.co.uk: Francis Crosby: 9780754823865: Books
Sikorsky XR-4 Helicopter | Smithsonian Institution
The Helicopter: A Hundred Years of Hovering | WIRED
World first: the DGA carried out a test flight of a military helicopter with very high-grade sustainable fuel without modifying the engine or the aircraft - EDR Magazine
Evolution of the Helicopter timeline | Timetoast timelines
Who designed the helicopter design first? - Quora
Where it all began: 1st production helicopter on display at museum | Article | The United States Army
World's first practical helicopter VS-300 took flight at Stratford on this day in 1939 | Rest of the World News
World's First Helicopter – Today in History: September 14 - Connecticut History | a CTHumanities Project
Who Invented the Helicopter? (and When?) - Aero Corner
