Offshore Wind Farm Helicopter Search and Rescue Trials 3 Report of the original trials As was noted in the trials report of November 2004 ( ref. 1) , the WTGs produced radar side lobe, reflected and multiple spurious echo effects with blind and shadow sectors. The effect was that other turbines and vessels in these areas may not be detected and displayed. Additionally, the strong response of the WTGs when nearby, and with their close spacing, appeared to produce saturation areas in which targets were not detected, particularly if radar receiver gain was reduced to cancel side lobe and other spurious echoes. 4 Helicopter search and rescue trials The foregoing effects were determined using only ship-borne and shore-based marine radar systems. These included those carried in the Rhyl and Hoylake Mersey Class RNLI lifeboats. However the RAF, RN and HM Coastguard all contribute greatly to search and rescue operations at sea and therefore it was considered necessary to assess representative systems used in helicopters. It was originally hoped that this could be done during the trials periods in July and August 2004 but, for operational reasons, it was not possible and arrangements were made to do this on 22nd March 2005. The aircraft carrying out the trials was a Sea King Mark lll of C Flight, 22 Squadron, Royal Air Force, of RAF Valley, Anglesey, in whose operational area the North Hoyle wind farm lies. A number of other consented Round 1 and proposed Round 2 wind farms will also be in RAF Valley’s area of responsibility when constructed. Fig 5 : Mk lll Sea King of C Flight , 22 Squadron, used in the trials Pilot Sqdn Ldr J.M. Stanley, Officer Commanding The majority of the aircraft systems relating to search and rescue are described in Squadron Leader J.M. Stanley’s report ( Section 9) Radar details not included in that section are : Operational frequency - 9240 MHz Pulse length - 0.5 microsec Beam width ( in azimuth) - 4° Beam width ( in elevation)- 5° Blind arcs - 30° ahead & approx 4° astern ( due to to gearboxes and engines) The aircraft operates with a crew of four : Two pilots ( Captain and co-pilot ), a medically qualified winchman and a radar / winch operator Note : Section 12 of Squadron Leader Stanley’s report on page 16 explains that the radar operator doubles as the rescue hoist operator. As can be seen from figures 8, 9 & 10, the radar console will not be visible from the rescue hoist position or from the cockpit – i.e. once the rescue hoist is in operation the pilots are radar blind. |
