What happened
On July 15, 2016, during preparations for a mission at Szczecin-Goleniów Airport (EPSC), a Piaggio P.180 Avanti I operated by the Warsaw Air Ambulance (Lotnicze Pogotowie Ratunkowe) experienced technical irregularities. After the aircraft's electrical power was engaged, a BUS DISC warning appeared on the warning panel, indicating an electrical system fault. Simultaneously, the crew observed that the aircraft was tilting to the right side.
Upon inspection, a difference in the compression of the main landing gear struts of approximately 1.5 cm was identified. Technical personnel determined that the pressure in the right main landing gear strut was only 820 PSI, significantly below the required 1095 PSI specified in the Aircraft Maintenance Manual (AMM).
The investigation
The investigation established that the right main landing gear strut had been installed on the aircraft the previous day, July 14, 2016. The low pressure caused the aircraft to tilt, which in turn resulted in an incorrect position of the Weight On Wheels (WOW) sensor on the right main landing gear strut, triggering the electrical warning.
Findings
- The primary cause was the incomplete and improper execution of the strut replacement process, specifically the failure to recharge the strut to the required pressure.
- A lack of adequate supervision and quality control during the replacement of the right main landing gear strut contributed to the incident.