What happened
On September 10, 2016, during a maintenance inspection of an Embraer ERJ-135 Legacy 600 at the user's hangar at Warsaw Chopin Airport (EPWA), a tool was discovered left inside the aircraft structure. The tool, a pair of wire cutters, was found behind a cover in the landing gear bay.
The discovery was made on January 2, 2017, by mechanics from an external maintenance organization performing an inspection. The tool was identified as belonging to a mechanic from the aircraft operator via a serial number engraved on the handle. The tool had been left behind during previous maintenance activities completed by the operator's staff on the date of the incident.
Although the tool was located in a position where it could not fall out or strike sensitive moving components, its presence within the airframe constituted a maintenance incident.
The investigation
The investigation focused on determining how the tool remained inside the aircraft structure after the completion of maintenance tasks. It was established that the tool was left behind during maintenance work performed by the operator's mechanics, which concluded on September 10, 2016.
Findings
- Human error, specifically the failure to account for all tools following maintenance tasks.
- Inadequate procedures regarding tool control and management during maintenance operations.