What happened
On 12 August 2024, an ATR 72-XX (registration LY-JUP) was conducting a scheduled passenger service from Southampton to Guernsey Airport. As the aircraft approached Runway 27, the crew continued their descent below the 1,000 ft approach ban altitude, despite the reported Runway Visual Range (RVR) being below the required 550 m for a CAT 1 approach.
As the aircraft reached the decision altitude, the crew experienced significant confusion. While the commander believed he had visual references to land, the co-pilot, perceiving no response to his call of "Minimums," initiated a go-around. During the subsequent maneuver, the aircraft failed to climb effectively. For approximately 15 seconds, the aircraft remained at a radio altitude of between 61 and 78 ft agl, maintaining a level pitch attitude despite the application of full power. The flight eventually established a climb and diverted to Southampton Airport, where it landed safely.
The investigation
The AAIB investigation examined flight data recorder (FDR) information, air traffic control recordings, and RVR data. The investigation established that the approach ban was not discussed during the pre-flight or approach briefings. The investigation also looked into the technical performance of the aircraft's automatic flight control system and the crew's communication patterns.
It was noted that the crew members did not share a common native language, and the operator's assessment framework at the time did not include a standalone category for communication skills. The investigation also found that the commander may have been operating under an outdated understanding of the regulations regarding approach minima.
Findings
- The crew continued the approach below the 1,000 ft approach ban altitude despite the RVR being below the required threshold.
- A lack of shared mental model and ineffective communication between the crew led to confusion regarding the aircraft's visual references and the necessity of the go-around.
- The commander did not challenge the approach below the ban altitude, and the co-pilot did not intervene when the aircraft passed the ban point.
- During the go-around, the aircraft's pitch remained insufficient to establish a climb for 15 seconds, leaving the aircraft at a dangerously low altitude above the airfield.
- The co-pilot did not attempt to take manual control to correct the flight path when the aircraft failed to climb, and the commander did not respond to prompts regarding the landing gear.
Safety action
Following the incident, the operator implemented several safety improvements, including:
- The introduction of a Flight Data Monitoring (FDM) programme.
- Enhanced recruitment processes involving psychological assessments.
- Revised simulator training requiring co-pilots to actively challenge deviations or errors.
- Updated guidance for instructors to emphasize crew coordination and collaboration.