First practical use of cyclic pitch (Hafner A.R.III)
Thursday, September 19, 1935 - Heston Aerodrome, United Kingdom
The pilot was Capt. Baker. More details of the aircraft can be found in NACA-AC-205, which shows a detailed view of the arrangement of the cyclic control (see Figs 4,5,6). The aircraft carried registration G-ADMV.
Note: The milestone date is the date of the article below. The actual date in September is believed to be a few days earlier.
Source: "Noteable Newcomers", FLIGHT, September 19, 1935