STOL a military animal....que..?
Old Sybl..VH-SIB was a TU-206 with a Robertson STOL conversion. Modified leading edge, droopy ailerons with the flaps, extended wings. Had been operated with SIL / Summer Institute of Linguistics in the highlands of PNG. STOL capabilities being the go for the "airstips" there. Could certainly do the tight spots ok.
A Higher Authority trod on it in the BNE super cell storm Jan 1986. Vale SIBL.
There is a Wren Cessna 180 about, also a STOL conversion.
I guess they were certified as per the mods for STOL ops.
These days there are 'flying ' gadgets about for off field landings like the LSA Highlander STOL. Bit of a breeze and its landing run = length of the aeroplane !!
I want one .