The disaster was the crash of an RAF Chinook helicopter (ZD576) into the side of a mountain on the Mull of Kintyre (SW Scotland). It killed everyone on board instantly: four crew and 25 passengers, the latter all experienced counter-intelligence officers (police and military), headed for a conference at Fort George near Inverness. Their speciality was dealing with the IRA insurgency in Northern Ireland, from where they came.
I described the incident in the only book devoted entirely to this accident (Chinook Crash), published in 2004. I covered, not just the background to the flight and the crash itself, but the complicated aftermath, which included several inquiries, from a Scottish Fatal Accident Inquiry to debates and inquiries in the UK Parliament (the Scottish Parliament has never interested itself in the matter). My book also described a possible cause of the accident—namely a navigation error.