Here are two press cuttings about the incident:
The aircraft is variously described in these and other cuttings as a "Sundowner Beechcraft Musketeer" and a "Piper Muskateer". Helpfully, one of the cuttings above identifies the aeroplane as VH-UMH. The aircraft was eventually talked down by two DCA Examiners of Airmen in a Departmental Beech Bonanza (probably VH-CAB).
Rgds