Sycamore, thank you for the info. Anyway my aging brain was probably momentarily in QFE mode. Hunter went on to do circuits at Waddington and Humberside 'International'.
I preface this by pleading I was indoors. On the subject of sound playing tricks, what I initially thought was a distant Chinook, earlier today, rapidly transformed into an R22. I am clearly not getting enough sleep. Not a mistake I would have made when a Chinook passed close by at what, from its apparent size, looked like <200' just under the extremely low cloud earlier this week. (Transponder off or too low to register)