Investigators looking at a near miss between a light plane and an Air New Zealand passenger aircraft near Mercer south of Auckland last year have blamed air traffic controllers for not following procedures.
A Cessna 182 which had just dropped four parachutists on August 9 and had only the pilot on board nearly collided with an Air New Zealand Bombardier carrying three crew and 31 passengers on a scheduled flight from Auckland to Tauranga.
The Transport Accident Investigation Commission (TAIC) said both aircraft had been cleared by air traffic controllers at Auckland airport, but the Air New Zealand aircraft's own sensors detected the Cessna and a possible mid-air collision was avoided because of the actions of its crew.
In the TAIC report several issues identified were:
• the two-member air traffic control team managing the airspace did not ensure a third member of the team was available when needed;
• when he cleared the airline to its destination the controller did not fully examine the route it was to take and along which the parachute aircraft was operating;
• the two air traffic controllers did not recognise the developing conflict as the two aircraft approached each other, and
• an automated collision warning in the control centre was missed.
After the incident, the pilot of the Cessna said the other aircraft passed about 400 feet below him and he had no time to react.
The crew of the Air New Zealand flight said the Cessna was "very close" when it passed overhead.
When both aircraft told the air traffic control of the near miss, the controller was relieved.
TAIC made several recommendations to improve air safety, including a review of some procedures at Mercer because it was close to a busy domestic and international airport.
It also recommended that more be done to look at the performance of individual air traffic controllers and to reduce communications errors.
The system warning controllers of potential risks also needed to be reviewed.
TAIC also recommended the installation of a recording system to capture verbal communications between controllers which could be use as valuable lessons when an incident happened.
