What a machine! Although the aircraft is on the FAA register as a "McKinnon G-21G" c/n 1240, the conversion was done by US Fisheries & Wildlife Service. It is not a G-21G, but merely a G-21A fitted with TPE331 turbine engines (in 1971), a 40 inch fuselage extension (in 1974) and some G-21G modifications. There was no known involvement of McKinnon.