Advanced Helicopter Flight Principles (Part II) 1955 US Army Pilot Training Film TF46-2211 (Patreon)

more at http://quickfound.net/

Originally a public domain film from the US Army, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.

The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).

https://en.wikipedia.org/wiki/Helicopter

Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/

A helicopter... is a type of rotorcraft in which lift and thrust are supplied by 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 and many forms of VTOL (Vertical TakeOff and Landing) aircraft cannot perform.

The English word helicopter is adapted from the French word hélicoptère, coined by Gustave Ponton d'Amécourt in 1861, which originates from the Greek helix (ἕλιξ) "helix, spiral, whirl, convolution" and pteron (πτερόν) "wing". English language nicknames for helicopter include "chopper", "copter", "helo", "heli", and "whirlybird"...

https://en.wikipedia.org/wiki/Bell_H-13_Sioux

The Bell H-13 Sioux was a single-engine single-rotor light helicopter built by Bell Helicopter. Westland Aircraft manufactured the Sioux under license for the British military as the Sioux AH.1 and HT.2...

In 1947, the United States Army Air Forces (later the United States Air Force) ordered the improved Bell Model 47A. Most were designated YR-13 and three winterized versions were designated YR-13A. The United States Army first ordered Bell 47s in 1948 under the designation H-13. These would later receive the name Sioux.

Initially, the United States Navy procured several Bell 47s, designated HTL-1, between 1947 and 1958. The United States Coast Guard evaluated this model, and procured two HTL-1s for multi-mission support in the New York Harbor. The most common U.S. Navy version of the 47 was designated the HTL-4, and dispenses with the fabric covering on the tail boom. The U.S. Coast Guard procured three HTL-5s in 1952 (similar to the HTL-4 but powered by a Franklin O-335-5 engine) and used these until 1960. The Coast Guard procured two of Bell's Model 47G and designated them HUL-1G in 1959.

The H-13 was used as an observation helicopter early in the Vietnam War, before being replaced by the Hughes OH-6 Cayuse in 1966...

https://en.wikipedia.org/wiki/Bell_47

The Bell 47 is a single rotor single engine light helicopter manufactured by Bell Helicopter. It was based on the third Bell 30 prototype, which was the company's first helicopter designed by Arthur M. Young. The 47 became the first helicopter certified for civilian use on 8 March 1946. More than 5,600 Bell 47s were produced, including those under license by Agusta in Italy, Kawasaki Heavy Industries in Japan, and Westland Aircraft in the United Kingdom. The Bell 47J Ranger is a modified version with a fully enclosed cabin and tail boom...

Design and development

Early models varied in appearance, with open cockpits or sheet metal cabins, fabric covered or open structures, some with four-wheel landing gear. Later model D and Korean War H-13D and E types settled on a more utilitarian style. The most common model, the 47G introduced in 1953, can be recognized by the full "soap bubble" canopy, exposed welded-tube tail boom, saddle fuel tanks and skid landing gear.

The later three-seat 47H had an enclosed cabin with full cowling and monocoque tail boom. It was an attempt to market a "luxury" version of the basic 47G. Relatively few were produced.

Engines were Franklin or Lycoming vertically mounted piston engines of 178 to 305 HP (150 to 230 kW). Seating varied from two (early 47s and the later G-5A) to four (the J and KH-4).

In April 2011 there were 1068 registered with the Federal Aviation Administration in the United States and 15 in the United Kingdom.

Bell 47s were produced in Japan by a Bell and Kawasaki venture; this led to the Kawasaki KH-4 variant, a four-seat version of the Model 47 with a cabin similar to the Bell 47J. It differed from the "J" in having a standard uncovered tail boom and fuel tanks like the G series. It was sold throughout Asia, and some were used in Australia.

In February 2010, the Bell 47 type certificates were transferred to Scott's Helicopter Services. The sister company that was formed, Scott's - Bell 47, is in the process of starting production of a turboshaft powered version of the Bell 47, the 47GT-6, using a Rolls-Royce RR300 engine and with composite rotor blades, with deliveries planned from 2016...