Land east of Llantwit Major was purchased in 1936 and RAF St Athan opened as a training centre for ground based fitters and flight engineers at 4 School of Technical Training, in 1938.
Aircraft maintenance has also been a feature of the work at St Athan on RAF and RN fixed-wing aircraft, including Harriers, Sea Harriers, Hawks, Jaguars, Tornados and VC-10s. Engineering work also involved repair and overhaul of aero-engines, mechanical and structural components, as well as providing upstream design and manufacturing services.
A grand plan emerged under DARA auspices to save cost and centralise all RAF 2nd line maintenance at St Athan. MoD had declared an intent to close St Athan but the then Welsh Development Agency was suckered into buying the site from the MoD and leasing parts of it back. With this arrangement in place, DARA then committed to build the
Super hangar as a state-of-the-art aircraft maintenance facility, which opened in Apr 2005. Once built, the RAF declared it had no intention of participating and consolidated all its Tornado fast jet work at
Marham. With the lack of critical mass, that project began to unravel and this also spelt the end for
DARA.
The Welsh Assembly was now looking for a use for the site and buildings it had inherited and was seeking to use the facilities and skills of the workforce to create an
Aerospace Centre of Excellence here (it is also quite close to
Cardiff International Airport).
An MoD Defence Training Review concluded this would be an ideal location for a tri-service engineering / training consolidation, which was also cancelled, in Oct 2010.

As a result of the
UKSRR SAR service main contract award from Apr 2015,
Bristow has been building new SAR facilities due to transition here from
22 Squadron A Flt
Sea Kings (from the
RMB Chivenor site), on 1 Jul 2015.

During Apr 2015, the base was host to a number of UK helicopters during the later phases of
Exercise Joint Warrior 15-1, including RAF
Chinook and
Puma and
846 NAS Merlin HC.3.
