Near collision involving a Cessna Aircraft Company 402C, VH-AZO and Cessna Aircraft Company 210M, VH-IDZ, 16km N Victoria River Downs, NT on 22 July 1994

VH-IDZ was enroute Darwin to Kalkgurung, tracking via Victoria River Downs, tracking 174 degrees at the correct cruising level of 9500 feet. About 16km north of Victoria River Downs the pilot observed another aircraft pass directly under him in the opposite direction with a vertical separation of 100-200 feet. The other aircraft, VH-AZO, was enroute from Tanami to Darwin via Victoria River Downs tracking 007 degrees, and also cruising correctly at 9500 feet. Changes made to Australian airspace, which replaced the quadrantal cruising levels with hemisphere cruising levels, allows opposing VFR traffic within the same hemisphere to operate at the same altitude.