What happened
On 06 March 2022, a Boeing 737-8AS, registration EI-EVR, operated by Ryanair, was performing a second approach to Málaga-Costa del Sol Airport (LEMG) following a missed approach. The initial approach had been aborted after the aircraft breached separation with a preceding plane on short final.
During the subsequent missed approach procedure, the flight crew requested radar vectors to reposition for a second attempt at runway 12. While cleared to descend to 6000 ft and proceed to the NEPUR waypoint, the crew descended to 4800 ft and later selected 3200 ft in the altitude window. The aircraft also deviated from the prescribed lateral path, turning right before reaching NEPUR and flying parallel to the MAR radial 148.
As the aircraft continued its descent, it breached several minimum vectoring altitudes (MVA) in the sectors it traversed. At 08:59 UTC, the aircraft's Ground Proximity Warning System (GPWS) issued a 'CAUTION TERRAIN' alert, followed by 'TERRAIN, TERRAIN, PULL UP' warnings. The autopilot disengaged, and the crew initiated a climb. The aircraft eventually intercepted the runway 12 localizer and landed safely with no injuries and no damage to the aircraft.
The investigation
The CIAIAC investigation focused on the deviation from the cleared flight path and the failure of altitude monitoring. Investigators examined the flight crew's decision-making regarding altitude selection and the aircraft's lateral navigation. The investigation also reviewed the air traffic control (ATC) performance, specifically the monitoring of the aircraft's altitude relative to cleared levels and the applicable MVAs. The study found that while the crew was concerned about fuel management, there was sufficient fuel to complete the approach as cleared.
Findings
- The flight crew failed to follow the cleared approach procedure, descending below the authorized 6000 ft altitude and deviating from the assigned lateral route.
- The aircraft flew below its cleared altitude for 2 minutes and 43 seconds before the GPWS alert.
- ATC failed to actively monitor and detect that the aircraft was flying below the cleared altitude and the prescribed minimum vectoring altitudes.
- The crew's decision to descend below the cleared altitude was not explicitly explained, though they reported high perceived workload.