What happened
On September 7, 2005, a Boeing 737-800, registration EI-DAV, was operating a scheduled flight from Niederrhein, Germany, to Rome Ciampino. During the approach, the crew encountered significant thunderstorm activity, necessitating several deviations from the original route. Due to the weather, the aircraft was diverted to Rome Fiumicino.
During the diversion, the crew's situational awareness degraded. While navigating through heavy turbulence and intense weather, the pilots descended below their assigned altitude of 3,000 feet without notification from Air Traffic Control (ATC). As the aircraft passed through 2,000 feet, it entered a traffic conflict with another aircraft approaching runway 34R. ATC instructed the crew to descend immediately to 1,000 feet to maintain separation. The crew continued the descent, eventually initiating a missed approach at approximately 454 feet above the ground—roughly 770 feet lower than the minimum altitude specified in the official instrument approach charts.
The investigation
The ANSV investigation examined the flight operations, crew performance, and air traffic control capabilities. The inquiry focused on the crew's management of the unplanned diversion, the impact of meteorological conditions, and the technical limitations of the Roma ACC radar sector. The investigation also reviewed the psychological state of the commander and the technical proficiency of the crew in managing complex radio navigation settings during high turbulence.
Findings
- The primary cause of the event was the improper flight management by the crew during the unplanned diversion to Fiumicino.
- The commander was experiencing significant psychological distress following a recent family bereavement.
- The co-pilot, facing his first experience with such severe weather, struggled to program the Flight Management System (FMS) and radio aids due to intense turbulence.
- There was a breakdown in crew coordination and integration, alongside a progressive loss of situational awareness.
- ATC communications were occasionally non-standard, and the crew failed to switch to the newly assigned radio frequency.
- The Roma ACC radar sector lacked real-time weather radar information availability for controllers to assist aircraft effectively.
- The radar system lacked a Minimum Safe Altitude Warning (MSAW) function, which would have alerted the controller when the aircraft descended below the sector minimum.