AO-1999-005

ATR 72-212 ZK-MCC and Boeing 737 ZK-NAT, airspace incident, Queenstown control zone, 26 July 1999
Status
Closed
Occurrence Date
Report Publication Date
Jurisdiction
NZ
Legacy Inquiry Number
99-005
On Monday 26 July 1999 at about 1250 hours, an Air New Zealand Boeing 737 was flying a circling instrument approach in the Queenstown Control Zone when a Mount Cook ATR 72 entered the zone without a clearance, infringing the separation requirements for the 2 aircraft.

The ATR 72 had descended early and was joining Queenstown under visual flight rules via Kawarau Gorge at low-level in poor weather. Before entering the gorge, the ATR 72 had been advised by air traffic control of a possible requirement to hold at a reporting point on the edge of the control zone. Committed to continue flying through the gorge in deteriorating weather, the ATR 72 was unable to hold at the reporting point when later instructed to. The crew of the ATR 72 had continued through the gorge in the belief that they did not need to obtain an entry clearance into the control zone.

Having entered the control zone the ATR 72 compromised the circling approach of the Boeing 737 that was operating in accordance with normal instrument flight rules procedures. The controller was initially unsure of the location and intended flight path of the Boeing 737, and when both aircraft were established in the zone he was left with little option than to position the ATR 72 in front of the Boeing 737. The captain of the Boeing 737 was then committed to continuing towards the aerodrome in reducing visibility because the ATR 72 had obstructed its primary escape route to the south of the aerodrome.

Safety issues identified were:
• the ATR 72 entering a control zone without an entry clearance
• safety procedures for flying through Kawarau Gorge
• a general poor industry understanding of the requirements for flight under special visual flight rules
• position reporting by aircraft after becoming visual on the instrument approach
• flight under visual flight rules by medium and large air transport aircraft
• poor industry understanding of the management of general aviation areas within the Queenstown Control Zone.

Recommendations were made to the operators of both aircraft, the Director of Civil Aviation and the Chief Executive of Airways Corporation to address the safety issues.
Related Safety Recommendation(s)
Location
Queenstown control zone (-45.000000,168.833331) [may be approximate]