What happened
During the night of December 30–31, 2016, a Bombardier/de Havilland DHC-8Q400 was undergoing an A-check at Warsaw Chopin Airport (EPWA). The maintenance was being performed by a maintenance organization at a hangar belonging to a different provider. All tools and materials required for the inspection were retrieved from a central warehouse.
During the maintenance process, a staff member left the work area to print necessary instruction cards. Following the completion of the inspection, the crew performed a standard tool and material inventory check before returning items to the warehouse. During this reconciliation, it was discovered that one flashlight was missing. The crew conducted an extensive search of the aircraft, the hangar floor, toolboxes, and nearby vehicles, and initiated the formal "Lost Tool Searching Protocol." Despite these efforts, the item remained unlocated.
After the aircraft was towed from the hangar and maintenance documentation was finalized, further searches were conducted within the maintenance facility's workshops, yielding no results. Shortly thereafter, the airport operator (EEPW) notified the maintenance organization that the flashlight had been found near the runway. The location of the discovery suggested that the tool had been left inside the aircraft and fell out during the takeoff roll.
The investigation
The investigation focused on the maintenance procedures and the tool control process during the A-check. The investigators examined the sequence of tool retrieval, the personnel movements during the inspection, and the effectiveness of the tool reconciliation process used by the maintenance organization.