What happened
On December 13, 2019, a Fairchild SA 227-AC (Metro III), registration SX-BKZ, operated by SWIFTAIR HELLAS, landed at Athens International Airport (LGAV) after a cargo flight from Thessaloniki. While the crew was taxiing via high-speed exit A6 to vacate runway 21R, the nose wheel steering suddenly and sharply turned to the left without any input from the commander.
In response to the unexpected movement, the pilot decided to stop the aircraft immediately. The sudden turn caused the nose gear and the left main landing gear to leave the paved surface and enter soft ground, while the right main gear remained on the taxiway. The crew performed a standard shutdown and evacuated the aircraft; no injuries were reported to the two crew members on board.
The investigation
The AAIASB investigation focused on maintenance records, pilot training, and the mechanical integrity of the steering system. Investigators reviewed the aircraft's maintenance history, noting that the nose wheels had undergone several interventions in 2019, including work for unbalanced wear in March and a routine removal for normal wear in October.
Following the incident, airline technicians inspected the steering system and found no identifiable malfunctions. As a precaution, the entire nose wheel assembly was replaced, and a hard landing check was performed on the aircraft. Flight data and cockpit voice recorders were analyzed but provided no specific clues regarding the sudden steering movement.
Findings
- The crew was properly licensed, certified, and medically fit for duty.
- The aircraft was airworthy with no pending items in the Minimum Equipment List (MEL).
- The nose wheel steering failure could not be specifically identified through mechanical inspection or data analysis.
- The investigation noted a pattern of similar unidentifiable steering malfunctions in other incidents involving this aircraft type, including previous cases in Spain and the United States.