A Qinetiq-led trial has demonstrated a new stabilised visual landing aid concept on board the UK Royal Navy's aircraft carrier HMS Illustrious, with the work forming part of a de-risking study into the use of a shipborne rolling vertical landing (SRVL) manoeuvre for Lockheed Martin's short take-off and vertical landing F-35B Joint Strike Fighter with the service's two future CVF vessels.
Qinetiq's two-seat VAAC Harrier testbed flew multiple approaches to a demonstration deck lighting array mounted on the ship, with a total of 66 sorties flown over a week-long period in November and successful approaches made in conditions up to Sea State 6.
© Royal Navy
An SRVL involves a STOVL aircraft executing a "running landing" along a carrier's axial flight deck, using air speed to provide wingborne lift to complement engine thrust. The touchdown position is similar to that of a conventional carrier, but with no arrestor gear used and the aircraft using its brakes to stop. The technique offers significant additional payload "bring back" for the F-35B, and the potential to extend engine life through reduced wear and tear.
The UK Ministry of Defence has funded research to refine and de-risk the use of the SRVL concept by the F-35B, the preferred choice for its Joint Combat Aircraft replacement for the BAE Systems Harrier GR9/9A. Previous work, including flight trials of the VAAC Harrier on board the French navy aircraft carrier Charles de Gaulle last year, has established the fundamental safety and operational benefit of the technique.
For the latest trial, a demonstration visual landing aid dubbed a "Bedford array" was installed in the port catwalk adjacent to Illustrious's flight deck. Taking inputs from inertial references to stabilise against deck motions, this is combined with a ship-referenced velocity vector in a helmet-mounted display to enable a pilot to fly an accurate approach to the deck on a constant glidepath. A second lighting array was rigged on the carrier's flight deck, and was used during a parallel evaluation of its visual acuity.
The VAAC Harrier flew representative approach profiles down to a safety height of around 40ft (12m) above the deck, and according to the Royal Navy, such was the accuracy of the array that a non-aircrew member of the embarked trials team was able to fly a perfect approach from the rear seat position of the trials aircraft while the safety pilot forward remained hands off.
© Runlikehell Gallery on flightglobal.com/airspace
The trial may prove to be the last research tasking for the VAAC Harrier testbed, with the 39-year-old aircraft (above) expected to be retired from use in early 2009.