More really great stuff, Dan. I've never seen the 1993 notes, I have the 1953 and 1966 ones, plus a 1969 Chipmunk T.10 Student Study Guide.
Just in case someone decides to try this at home, could I point out in reference to item (iii) "...more positive spin entry...by applying aileron opposite the direction..." that CAP 562 states "If aileron is so used it should be centralized when entry is achieved. Under Spin Recovery: "b) check ailerons CENTRAL;"
Lastly, in my posting on 26th Sept I made the comment: "..the Australian DCA published a report in June 1960 (i.e. two years after the RAF fitted their strakes) which never mentions the effectiveness or otherwise of this item?" Having finally located my references to this, I can categorically state that I was wrong!
Dan's earlier posting stated:
"An Australian document written in 1960 after flight testing of Chipmunks in response to series of accidents mentions that;
It was found that although the strakes had no effect on the entry, the spin itself or on the recovery of an aircraft with good recovery characteristics, they did tend to shorten the recovery time slightly on an aircraft normally slow to recover, but it was only a reduction in the order of three quarters of a turn in the worst case"
He is correct, this is an exact quote from the DCA document.