Wolkenhaar joined the RAAF on the 14th of August 1941. He arrived at 2OTU Mildura on the 14th of November 1943 ex 2BAGS for the No.26 course.
Wolkenhaar was carrying out ‘shadow shooting adjoining Lake Victoria in Spitfire A58-241 on 21 Dec 1943 accompanied by Flight Sergeant Morton as his No 2 for the exercise. Morton saw Wolkenhaar peel off from about 1,200 feet altitude in a steep dive for a front quarter attack on the shadow target some 800 yards from the edge of the lake. Wolkenhaar’s aircraft was flying very low when it struck the top of a sandbank in a range of sand hills 40 feet high. The aircraft caught fire on impact. Wolkenhaar was still alive when the ambulance arrived but sadly died on the way back to the Mildura aerodrome.