The crash seems to have indeed happened on a location on an extended downwind for 13 righthand about 3 NM (northwest) beyond Tango
http://www.austrocontrol.co.at/en/Im...m586-67006.pdf
the direction of the crash should indicate if he was indeed in the odd shaped circuit, and extended his downwind leg, or that this location is coincidental.
Alternatively he could have been on a long final for 13 or
still joining the procedure, although in that case his routing is peculiar (broadly heading 160), which seems less likely
Circuit height is 2500 ft MSL, the elevation of the "cone" is 2884 ft, Vienna III SRA extends down to 4500 ft