What happened
On February 18, 2020, at Warsaw-Okęcie Airport (EPWA), a crew from Lotnicze Pogotowie Ratunkowe (LPR) was performing a pre-flight inspection on a Piaggio P180 (registration SP-MXH) prior to a test flight. The purpose of the flight was to verify the rectification of a previously reported malfunction regarding the secondary pitch trim system. During the check, the pilot identified that the elevator trim was not functioning correctly in the primary mode, specifically that the trim could not be set to the "heavy tail" position, although the backup mode remained operational.
Technical personnel at the Warsaw-Okęcie Maintenance Station diagnosed a failure in the Horizontal Tail Trim Actuator (HTTA). To resolve the issue, a replacement actuator was retrieved from LPR's existing warehouse stock and installed. Following the installation, a successful functional test of the stabilizer controls was performed, and the subsequent test flight was completed with positive results.
The investigation
The investigation focused on the documentation and procurement process of the replacement component. Upon reviewing the maintenance records, the Continuing Airworthiness Management Department discovered that the installed actuator had been incorrectly labeled. The component had been placed into storage on December 7, 2015, with a specific shelf-life limitation expiring on March 23, 2018.
While the physical green tag attached to the actuator listed the part number (P/N: 70220100) and serial number (S/N: D33143) and noted "N/A" in the remarks/limitations section, the actual expiration date was documented on the associated EASA Form 1 (No. AXB34601) in field 12. This critical information was located at the bottom of the actuator's packaging rather than on the primary identification tag.
Findings
- The primary cause of the incident was a lack of proper oversight regarding the stored component.
- The warehouse clerk incorrectly processed the actuator into inventory, recording "N/A" for the time-limited storage period on both the receiving card and the green tag.
- Discrepancies existed between the physical tag and the EASA Form 1, which contained the actual expiration date.
Following the discovery, the expired actuator was removed and replaced with a new, valid component, after which a successful test flight was conducted and the aircraft was returned to service.
Safety action
- LPR operational and technical personnel are to be briefed on the incident.
- Periodic training for technical personnel will include reminders regarding procedures for the acceptance, inspection, and storage of components and materials from external suppliers, as well as the supervision of components.