Lancaster reunion television drama

Hello. I wonder if anyone can recall a television drama from, I believe, the early to mid 1970s about a reunion of a Lancaster crew?
I remember watching it one Saturday night and here is the plot (as far as I recollect). The pilot of a wartime Lancaster crew is now (in the 1970s) a wealthy and successful businessman. He arranges a reunion of his crew at his country estate. They have a grand dinner and then he tells them he has bought and restored a Lancaster that is on his land. He asks them to don flying kit and go to their crew positions for take off. I seem to remember the reason behind all of this was to do with some ‘unfinished business’ from the war or to atone for some mistake or other. The drama ended in tragedy when the plane crashed.
I thought it might have been an episode in the Tales of the Unexpected series (because of the quirky story line and twist at the end) but cannot see it listed e.g. on IMDB.
If anyone can provide more information such as name of the drama and where it might be possible to watch it again (perhaps YouTube) I would be very grateful.
I was prompted to post this after reading a thread about another TV drama featuring a Lancaster that was apparently part of the Armchair Theatre series. This seemed to provide the person asking the question with quite a lot of help.
Thanks in anticipation of help.