What happened
On September 27, 2022, an Airbus A320-214, registration HK5413, was performing a scheduled commercial passenger flight from San Andrés (SKSP) to Cali (SKCL). The aircraft was operating under IFR conditions during a night approach via the RNAV ASIKO1C arrival procedure.
While descending through the Cali Terminal Control Area (TMA), the crew deviated from the published arrival path, navigating directly to waypoint CL807 without verifying the minimum sector altitudes. As the aircraft flew over the mountainous terrain of the Los Farallones de Cali National Park, the Enhanced Ground Proximity Warning System (EGPWS) issued a 'TERRAIN' alert, followed by a 'PULL UP' warning.
At the moment of the warning, the aircraft was at approximately 1,740 feet radio altitude. The pilot flying (PF) responded by applying maximum thrust (TOGA) and executing an immediate climb. The aircraft reached a minimum altitude of 1,528 feet above the terrain before the warning ceased and the crew successfully continued the approach to land at SKCL without further incident. There were no injuries to the 171 passengers or 6 crew members, and no damage was sustained by the aircraft.
The investigation
The GRIAA investigation examined the flight data, cockpit voice recorder, and air traffic control (ATC) records. The investigation focused on the deviation from the RNAV arrival procedure, the crew's decision-making process, and the performance of the Cali ATC radar services. Investigators also reviewed the status of the Minimum Safe Altitude Warning (MSAW) system and the communication between the flight crew and controllers.
Findings
- The crew failed to strictly adhere to the ASIKO1C arrival procedure, opting to navigate directly to waypoint CL807 without checking terrain clearance.
- The crew's failure to follow established arrival procedures was a primary factor in the near-collision.
- There were significant breakdowns in Crew Resource Management (CRM), as the pilot flying did not communicate navigation intentions to the pilot monitoring, preventing the crew from detecting the altitude deviation.
- The pilot flying exhibited overconfidence, relying on visual references of the city and mountains which biased their judgment regarding terrain separation.
- ATC authorized the direct routing to CL807 without verifying the aircraft's position or altitude relative to minimum safe altitudes.
- The MSAW system had been intentionally disabled by Cali ATS to prevent frequent alerts, and no alternative safeguards were implemented to compensate for this loss of protection.
- The radar controller failed to utilize available resources to detect that the aircraft was flying outside of standard RNAV procedures and below minimum altitudes.