(2) when high intensity strobe lighting was (a) removed and (b) refitted to the second Sea King marks trials aircraft; and under whose authority this action was taken;
(3) whether the retro fitting of his Department’s Sea King helicopters with high intensity strobe lighting was approved at all stages of planning and installation by the helicopters’ manufacturers.
[holding answer 26 March 2008]: High Intensity Strobe Lighting (HISL) was progressively fitted to all Marks of the UK MOD Sea King fleet between 1983 and 2001:
Mark 3—Rear Light introduced in 1983; Forward Light introduced in 1985.
Mark 3a—1996 (fitted when the aircraft was introduced to service).
Mark 2—1997 (all Mark 2 aircraft have subsequently been converted to the Mark 7 standard).
The Mark 2 to Mark 7 conversion programme that was undertaken between 1999 and 2002 was conducted in two phases, giving rise to two different build-standards of trials aircraft. The trial installation of HISL was undertaken during the first phase before the equipment was transferred to the second phase trials aircraft and re-tested, prior to release to service. This approach was agreed jointly between the MOD and the helicopter Design Organisation (Westland Helicopters, now AgustaWestland).
The retro-fitting capability was introduced as a Service Modification—either a Service Engineering Modification (SEM) or Naval Service Modification (NSM)—where design, test and installation is undertaken by MOD personnel. In all cases, the Department is required to seek independent airworthiness advice before the modification is released to service. Additionally, MOD personnel are required to seek advice from the helicopter Design Organisation, as was the case for all Marks of HISL modification. For all Marks except Mark 5 and Mark 6 aircraft, the HISL modification has retrospectively been formally accepted onto the aircraft drawings by the helicopter manufacturer through a process called Cover Modification.