How the UK had a stealth attack helicopter design proposal almost a decade before the US RAH-66 Comanche. Former Leonardo Helicopters Chief Engineer on the Merlin Mk3 and Apache, JEREMY GRAHAM FRAeS reveals archive details of this never-before publicised Westland Helicopters low observable chopper proposal from the 1980s that have just come to light.
Image of one configuration of the WG 47 stealth attack helicopter that was studied by Westland as a private confidential proposal for the UK MoD requirements. Note that this is not the final WG 47 configuration described in the text below (Leonardo MW).
In 1984 the Westland Future Projects team proposed a solution to GST 3971, the “Light Attack Helicopter”, based on the Lynx/W30 dynamics family and identified as WG 44. This was the first of several AH proposals that incorporated low observable technologies across the broad spectrum of detectable signatures. These technologies in themselves derived from company experience with unmanned aircraft system design completed for projects SUPERVISOR and PHOENIX in the period 1977 to 1983.
The definitive development of the low observable AH project, by then identified as WG 47, was completed in 1987, as a confidential private venture activity running in parallel with the multi-national A129 LAH study led by Agusta but supported by Westland, Fokker, MBB and CASA. The WG 47 configuration defined an aircraft having a faceted fuselage with internal weapons, twin canted tail rotors and the pilot in the front seat of a tandem cockpit. Engine, environmental and cooling systems exhausts were integrated into a side-exiting infra-red suppressor and the cockpit transparencies were angled outward to eliminate optical glint to the horizon.
The Boeing-Sikorsky RAH-66 Comanche was cancelled in 2004. (Boeing)
Many of these design solutions presaged the US Army RAH-66 Comanche helicopter which was first shown in public at its roll-out in 1995. Some of the fuselage shaping principles developed for the AH studies were proposed by Westland for NH90 during the multi-national Feasibility and Cost Definition Study involving France, Germany, the UK and Holland: the production aircraft retains these features to this day.
The current NH90 helicopter incorporates fuselage shaping to reduce detectability. (Airbus)
An exclusive full article on this previously confidential Westlands helicopter project, only now unearthed in the company archives, by Jeremy Graham FRAeS will appear in a forthcoming edition of AEROSPACE magazine.