What happened
Two distinct incidents occurred at Auckland International Airport in 2007, both involving aircraft entering a runway in front of others already in motion or lined up.
On 29 May 2007, a Saab SF340A was holding on an angled taxiway when it received clearance to line up in front of an arriving Raytheon 1900D. Although the aerodrome controller attempted to issue an amended clearance, the transmission overlapped with the Saab crew's readback of the original instruction. To prevent a collision, the pilots of both aircraft performed evasive maneuvers, eventually stopping on the runway. There were no injuries or damage reported.
On 1 August 2007, a second incident involved a Raytheon 1900D holding on an angled taxiway. The crew mistakenly accepted a takeoff clearance intended for a different Raytheon 1900D that was already on the runway and possessed a similar call sign. Both crews read back the clearance, and while the controller heard the error, no corrective action was taken. The holding aircraft entered the runway ahead of the aircraft that had already begun its takeoff roll. The pilots of both aircraft took avoiding action and stopped on the runway without any damage or injury.
The investigation
The investigation examined the operational environment at Auckland International Airport, specifically focusing on the use of angled taxiways for runway entry. Investigators looked into the handling of flight progress strips for departing traffic and the effectiveness of radiotelephony (RTF) procedures. The inquiry also assessed how the Civil Aviation Authority of New Zealand (CAA) recorded and defined runway incursions, noting that a consistent method for investigating such incidents had not previously been established.
Findings
Several contributing factors were identified across both events:
- The use of angled taxiways, which can create restricted cockpit visibility for pilots attempting to monitor runway traffic.
- Ineffective management of flight progress strips for departing aircraft.
- Non-adherence to standard radiotelephony procedures, including the failure to correct crossed transmissions.
- Confusion caused by similar call signs during clearance delivery.
- The captain of the entering aircraft failed to visually identify the traffic already on the runway.
Safety action
The investigation highlighted the need for improved procedures regarding the issuance and acceptance of conditional clearances for runway entry, particularly for aircraft types with limited visibility when positioned on angled taxiways.