The world’s first ‘practical’ helicopter, designed by Igor Sikorsky, took to the air at Stratford, Connecticut, on September 14, 1939.
The helicopter named VS-300 was built by the Vought-Sikorsky Aircraft Division of the United Aircraft Corporation. It was the first to incorporate a single main rotor and tail rotor design.
The helicopter took a tethered flight, which means that the aircraft was connected via a measured tether or a cable to the ground. This is actually a safety measure to ensure the helicopter does not rise too high during testing and to help prevent the helicopter from becoming uncontrollable.
As the pilot becomes more familiar with the helicopter, or the helicopter is trimmed and controls adjusted, the tether is lengthened or done away with completely.
The first flight of VS-300 only lasted just a few seconds. The VS-300 had a 28-foot diameter, three-blade, variable pitch rotor, with a blade speed of 250 to 300 mph. This helicopter provided the basis for the first production helicopters and it also became the standard for helicopter manufacturing across the globe.
Sikorsky submitted the patent application for a direct lift aircraft, which included all major engineering features of the VS-300 on June 27, 1931. Four years later, the patent was then granted on March 19, 1935.
Development of VS-300
While developing the concept of the rotary-wing flight, Sikorsky was the first to introduce a single engine to power both the main and tail rotor systems. The designer later added a vertical air-foil surface to the end of the tail in a bid to assist anti-torque. However, this was later removed when it proved to be ineffective.
Sikorsky added two smaller vertical-axis lifting rotors to either side aft of the tailbone as the cyclic control was found to be difficult to perfect. By varying pitch of the rotors simultaneously, fore and aft control was then provided. Roll control, on the other hand, was provided by differential pitching of the blades.
It was in 1941, that Sikorsky fitted utility floats to the VS-300 and performed a water landing and take-off. On May 6, 1941, the VS-300 beat the world endurance record, by staying aloft for 1 hour 32 minutes and 26 seconds.
The final variant of VS-300 was powered by 150 hp Franklin engine. The VS300 was one of the first helicopters capable of carrying cargo. Over a two-year-period, VS-300 was modified until the new cyclic control system gave much improved flight behaviour.
Today, this helicopter remains on display at the Henry Ford Museum in Michigan.
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally-spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally.
These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft cannot operate due to space limitations.
The English word ‘helicopter’ is adapted from the French word ‘hélicoptère’, coined by Gustave Ponton d’Amécourt in 1861, which originates from the Greek word ‘helix’ or ‘spiral, whirl, convolution and pteron’ meaning wing.
English language slang nicknames for helicopter include ‘chopper, copter, heli, helo and whirlybird.’
The world’s first operational helicopter was the Focke-Wulf Fw61, flown in 1936.
It was not until 1942 that a helicopter designed by Igor Sikorsky reached full-scale production, with only 131 aircraft built. Earlier designs used more than one main rotor, the configuration of a single main rotor (mono-copter) accompanied by a vertical anti-torque tail rotor has become the most common helicopter configuration.
Alternative Helicopter Designs
Twin-main rotor helicopters (bi-copters), in either tandem or transverse rotor configurations, are also in use due to their greater payload capacity than the mono-rotor design.
Co-axial rotor helicopters, tilt-rotor aircraft, and compound helicopters are all flying today.
Quad-rotor helicopters (quad-copters) were pioneered as early as 1907 in France, and other types of multi-copters have been developed for specialized applications such as drones.
Igor Sikorsky would always fly with his hat on, and used to test his own designs himself, and only later using a test pilot. Considering that all his early helicopters were open cockpit designs, this was very unique, as was the man himself.