G-AZOM
I was PAX on G-AZOM's penultimate flight. In 1984 helicopters were like hen's teeth and I organised a Shell charter of OM for a day from Norfolk to move survey positioning beacons in the outer isles of the Hebridean Sea for a seismic survey ship pre-GPS. The beacons were scarce too so the only way to cover the large survey area was by helicopter movement. I joined at GLA and we spent the day out at Islay and Barra Head refuelling at Benbecula. They dropped me at GLA and headed back to North Denes. I got back to Shell London two days later and was reading Lloyds List where OM's demise was reported. I remember being shocked as I had just got the photos back and remembered the call-sign from them. As you say, and quite amazingly, no casualties. I seem to recall the wrong grease was used in the tail rotor gearbox which seized causing the unfortunate series of events.
I liked the 105s, they felt safe and I flew in them a lot around the Northern fields in the North Sea.