"The Flying Club" is a very good episode from Season 16.
However, before reading this review, read the review that is titled "Competently made bit of hokum" as the person who wrote this knows his planes, and what he had to say was interesting.
A flying instructor, Bernard King, is hit on the head and flown in his own plane over a lake and dropped. DCI Barnaby and DS Nelson are on the case.
The flying club is run by Perry Darnley. He is from a family of fliers; his father flew during WW II, and his mother delivered planes to bases as a member of the Air Transport Auxiliary. Darnley's son flies for the RAF.
They find the murder weapon in an employee's work box. This man carries a very heavy grudge against the elder Mrs. Darnley. He denies having anything to do with the murder.
There are a few possible motives for the murder as well as suspects: the company was being restructured which would cause people to lose their jobs. Then there is a second murder, reminiscent of a famous scene in a Hitchcock film. The victim had a record of landing at night with no lights. Barnaby suspects a smuggling operation.
Good episode, with the usual past secret coming to light, but this time not attached to the murder.
Barnaby's alone with Sykes as his wife is off visiting, and there are some cute scenes with the two of them.
June Whitfield, who plays the ditsy mother on Absolutely Fabulous, is absolutely fabulous here in a dramatic role as a proud, accomplished woman. I read a little about her after seeing this - being American, I didn't realize that she has had an amazing career.
Enjoyable.