Formed from 447 Flight RAF with Swordfish. Disbanded at Lee-on-Solent in 1940. After a 4 month existence during early 1945, it reformed on 7 May 1947 with the Sikorsky R4 Hoverfly element from 771 NAS
, at RNAS Gosport as the Helicopter Fleet Requirements Unit. Operated the Dragonfly from Dec 1949 and during Jan and Feb 1951 conducted experimental ship landings aboard RFA Fort Duquesne
(A229). Sikorsky S-55s from November 1952, followed by British built Whirlwind HAR.1s and Hiller HT.1s in 1953. On 1 Feb 1953 the unit responded to a Dutch Government request to assist with relief from severe flooding in the Netherlands
by despatching 5 Dragonfly. It became the Helicopter Training Squadron in November 1955 and moved to RNAS Lee-on-Solent.
Moved to RNAS Culdrose in January 1958. The Hiller HT.2 (introduced in 1963) was replaced by the Gazelle HT.2 between Mar 1974 and Mar 1975 and the Whirlwinds were phased out.
In April 1997, the tri-service Defence Helicopter Flying School was formed and 705 moved to RAF Shawbury as the Advanced Single-engine Rotary Wing squadron. Some Gazelles were transferring to the RAF
and the Eurocopter Squirrel HT.1 was adopted.