Retired BA/BY
I "Googled' after I had made my post and I was right about the name, but wrong about the details - as you said he was not killed in a collision, and it was later in the 70s than I thought.
Stack lived in the same village as me in North Dorset for a few years, and once at his house there was an ex-Herc guy I had not known, that Stack had met when he used to fly BA 747s down to the Falklands. IIRC the guy had joined BY at his 38pt and after a year or two joined BA - hence I made the wrong assumption! IIRC initials LR.
I did my LHR ATCO Concorde jolly with Stack - absolute star! He could tell jokes all night and had everyone in our pub in stitches.
Apologies for the thread drift folks.