Friday, 23 March 2012

Quadcopter History 101


I would like to correct my statement last week that we have recently achieved manned flight with Multicopters. This was achieved nearly 100 years ago!

The de Bothezat helicopter was an experimental quadrotor helicopter built for the United States Army Air Service by George de Bothezat in the early 1920s, and was said at the time to be the first successful helicopter. Although its massive six-bladed rotors allowed the craft to successfully fly, it suffered from complexity, control difficulties, and high pilot workload, and was reportedly only capable of forwards flight in a favorable wind. The Army canceled the program in 1924, and the aircraft was scrapped.
Working almost entirely without models or wind tunnels, de Bothezat's helicopter was completed in December of 1922. Featuring four six-bladed rotors at the end of massive, bridge-like girders braced with piano wire, the craft had two vertical propellers – "steering airscrews" – for lateral control, and two additional three-bladed propellers mounted horizontally above the Le Rhône engine to provide airflow for cooling. The rotors tilted in towards the craft's center at an angle of five degrees, enhancing stability. The aircraft had two control wheels, a control stick, and foot pedals for control, with each rotor featuring variable-pitch blades for individual collective control.
After initial ground testing, the de Bothezat machine made its first flight on 18 December 1922, piloted by Major T.H. Bane of the US Army Engineering Division, and hovering to a height of 1.8 m (6 feet). The propellers for lateral control were soon found useless and removed. Its original Le Rhône engine proved underpowered and was replaced by a Bentley rotary type. Over the next year, over one hundred flights were made, carrying up to four passengers in addition to its pilot, and setting records for duration (2 minutes 45 seconds) and altitude - 9.1 m (30 feet) for helicopter flight.

I do believe if he just had a gyro /accelerometer based control board (now available for about a hundred bucks), I'd be driving to work in a quadcopter tomorrow.

1 comment:

  1. Awesome this will be my next project

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