Tiger Airways has implemented an auditable process for identifying and managing navigational database anomalies that were a primary contributor to the incident on June 7 2011 that allowed the crew of an A320 on approach to Melbourne to descend 500ft below the minimum altitude of 2,500ft, the ATSB has said in its report on the incident.
The crew had been relying on incorrect information loaded into the aircraft’s flight navigation systems and had not picked up an anomaly between the incorrect information displayed on the aircraft’s electronic systems and paper charts that showed the altitude limitation.
In its findings on the incident, the ATSB said: “…there was an increased risk of inadvertent non-compliance with published instrument approach procedures because of the inconsistent application of the operator’s safety management system to the identification and management of database anomalies. In addition, different assumptions by the data suppliers and the operator compromised the quality assurance of the navigational data.”
It wasn’t until air traffic controllers intervened while the aircraft was 17km from the airfield that the crew re-established the aircraft on the correct approach altitude.
“This occurrence reinforces the safety benefits of a resilient safety management system and operator procedures in the management of safety-critical database and other information. The accurate application of those procedures by all key personnel is also important as a safety defence.”