Boeing, the current AH-64 manufacturer, took over McDonnell Douglas, who in turn had taken over Hughes, the original Apache designers, all work is carried out at Mesa, Arizona.
Agusta-Westland is the helicopter company based at Yeovil who are responsible for final assembly and support.
QinetiQ at Boscombe Down performs test and evaluation functions for the MoD.
2 Regiment AAC at Middle Wallop is the main Army Air Corps Training Centre
651 Sqn was the "fielding squadron". Once the Apache had been introduced into service, the role was no longer required and so the squadron disbanded.
654 Sqn was previously part of 4 Rgt at Wattisham, but disbanded in July 2014
667 Sqn is the trials unit (previously the D&TS)
673 Sqn is responsible for converting AAC crew to the Longbow
3 Regiment AAC at Wattisham are assigned to 16 Air Assault Brigade
653 Sqn In 2015 it became the Apache OCU
4 Regiment AAC at Wattisham are assigned to 16 Air Assault Brigade
7 Regiment AAC at Middle Wallop took over all flying units there from 2 Rgt during 2009
9 Regiment AAC at Dishforth introduced the Apache into operational service. Its units subsequently moved to Wattisham under 4 Regiment
7 Air Assault Battalion REME at Wattisham take care of major in-field maintenance, and many minor modifications
Air Manoeuvre Training Advisory Team (AMTAT) moved to each unit in order to help prepare for Apache introduction