Yes indeed, its the "
Slip-
Wing Hurricane", but the Internet bugbear strikes again! Wasn't for ferry range, or extra tankage! Hillson's DID do the conversion....but it wasn't known as the FH 40 that was a completely different and VERY funky-looking lightweight fighter prototype.....
The purpose of the
Slip-
Wing Hurricane was VERY simple - it was for extra lift ONLY, so that the
Hurricane became an instant STOL aircraft for short lengths of roadway, tiny fields etc. .....in time of invasion LOL It was built and flown once in late Summer, 1940...the idea being that once airborne in a few dozen yards, "
slip" the
wing" and fly normally. Very useful of your last airfields are destroyed or overrun.
By the time the conversion was completed and ready for testing, the requirement - like those for emergency fighters etc. - was over, and the
Hurricane in THIS mode only made one short hop to prove the theory, and the
wing was never jettisoned

The real FH40 went through quite a life of testing for the next couple of years.
"Well, my days of not taking you seriously are certainly coming to a middle." - Malcolm Reynolds