Hello Nige
His logbook has two entries for that day ; Self.......Cadets 1hr.45 and 2.10. Presumably before and after lunch.
If I remember rightly , 20mins was the usual flight time.
Pleased to be of help
A few pages ago in this thread there is a photo of WK576 at Roborough, Plymouth, on 11th February 1967. My father is in the front seat.
I'm finding these bits of various jigsaws interesting and hopefully will be able to fill in more details in the future
Best wishes
Chipnostalgia