What happened
On March 16, 2016, during a routine hangar maintenance inspection at the EPWA technical base, a defect was discovered on a Piaggio P.180 Avanti II operated by SPZOZ Lotnicze Pogotowie Ratunkowe. The inspection was being conducted as part of a scheduled maintenance task following 200 flight hours.
During a visual examination of the brake assembly, personnel identified that eight rivets on the outer rotor disc had become detached or sheared. The brake assembly in question (P/N 2-1504-4) had been previously installed on the aircraft on August 15, 2015, following a repair. Since that installation, the aircraft had completed 592 landings. The damaged component was subsequently replaced with a serviceable, overhauled unit in accordance with the Aircraft Maintenance Manual (AMM 32-42-00).
The investigation
The investigation, conducted by the operator, focused on the structural integrity of the brake assembly and the history of its installation. The inquiry examined the condition of the rotor disc and the state of the rivets that had failed. The investigation confirmed that the failure occurred on the outer rotor disc of the brake assembly.
Findings
The investigation established that the primary cause of the incident was improper riveting during the assembly process or excessive installation clearance that developed during the manufacturing of the brake assembly component.