Aircraft No: K307

I have found old notes & papers from my father-in-law, Polish Flight Officer Boleslaw Palej, and it lists a forced landing, but the date (year) is not clear, perhaps you can help. The details as follows:
Form 171
Aircraft number K307
No 26 AC Squadron RAF Catterick
Date of forced landing: 5-7-40 at 1500 hours
Place of landing: Little Biggleswick, Manor farm, Thirsk, Yorks (place is unclear on the page)
Nearest railway station: Thirsk
Nearest RAF Station: Dishforth
Description of circumstances in which forced landing was made: Lack of oil pressure due to fractured pipe
Name & address of prospective claimant: Leslie …., …. Thirsk, York
Extent of damage: 20 yds of fence torn down
This date seems very early, the page is written in pencil that has faded & is quite difficult to read. If anyone could shed some light on this aircraft or incident I would be very greatful
etsah57