AO-2009-005

Cessna 182N, ZK-FGZ. Courtesy of NZ Skydive Ltd.
Cessna 182N, ZK-FGZ. Courtesy of NZ Skydive Ltd.
Cessna 182N ZK-FGZ and Bombardier DHC-8 Q311 ZK-NEF,
loss of separation and near collision, Mercer, 40 km south of Auckland, 9 August 2009
Status
Closed
Occurrence Date
Report Publication Date
Jurisdiction
NZ
Legacy Inquiry Number
09-005
ATC issues led to a loss of required separation and a near collision between a Cessna 182 parachute-drop aircraft with a single pilot on board and a Bombardier DHC-8 Q311 airliner with 3 crew and 31 passengers on board near Mercer on 9 August 2009.
Both aircraft were operating as cleared by ATC when the airliner’s equipment detected the conflict and directed it away from a potential collision with the parachute-drop aircraft, which had just dispatched 4 parachutists and commenced its descent.
The ATC issues identified were that: the 2-member ATC team managing the airspace did not ensure that a third member of the team was available as required the controller, in clearing the airliner to its destination, did not fully examine the route it was to take and along which a parachuting aircraft was operating the 2 controllers did not recognise the developing conflict as the 2 aircraft approached each other an automated collision warning in the control centre was missed.
During the investigation it was found that an Airways Corporation of New Zealand-sponsored audit had identified that the ATC centre had a rate of communication-related errors higher than those of other comparable control centres, although this type of error was not involved in this incident.
Since the incident, ATC has improved the visibility of the parachute drop area on controllers' screens, and is determining if the activation of the collision warning can be made more distinct. The parachute-drop aircraft has been fitted, beyond requirements, with collision-avoidance equipment similar to that on the airliner.
The Commission has made 5 recommendations to the Director of Civil Aviation to address safety issues relating to the operation and air traffic management of parachute drop areas, ATC's internal standards' monitoring, how the high number of general communication errors was being addressed, and controller actions following collision warning alerts. A sixth recommendation was made to the Director of Civil Aviation, to progress legislation for the acquisition and protection of controller-station recordings to assist future safety investigations.
(Note: this executive summary condenses content to highlight key points to readers and does so in simpler English and with less technical precision than the remainder of the report.)
Location
near Mercer (-37.203535,175.144043) [may be approximate]