As Two's In has indicated, a letter explaining who you are and therefore the purpose of your enquiry should be addressed to;
Aviation Standards
Army Air Corps Centre
Middle Wallop
Stockbridge
Hants
If the accident report is available, they may, and I reiterate may let you have a copy.
The accident was well briefed amongst the Army Lynx fraternity, but I am reluctant to disclose details on an open forum.