What happened
During a scheduled periodic maintenance inspection at a certified maintenance organization (CAMO) based at EPBC, structural damage and deformations were discovered on a Czech Sport Aircraft PS-28 Sport Cruiser. The findings, reported in two separate technical occurrence reports in June and July 2015, revealed damage to the firewall, the nose gear attachment to the firewall, and the onset of damage to the firewall longitudinal members.
Initial inspections on June 22, 2015, identified a crack in the 'Bulkhead 1 bracket'. While the aircraft was initially permitted to continue flying under a strict inspection regime—requiring checks of the nose gear attachment every 25 landings—a subsequent inspection on July 17, 2015, revealed further degradation, specifically the buckling of the firewall longitudinal members.
At the time of the findings, the aircraft had a total time in service of 298.2 hours and 278 flight cycles. The aircraft was primarily used for intensive flight training operations, utilizing a concrete runway for takeoffs and landings, but frequently taxiing on unpaved, grass surfaces.
The investigation
The investigation focused on the nature of the structural deformations and their progression. The analysis established that the damage was caused by fatigue phenomena resulting from the specific operational profile of the aircraft and its design characteristics. The investigation noted that the aircraft's structure was not sufficiently adapted for the high-intensity flight training environment, particularly when operating on uneven surfaces. This pattern of damage was noted to be consistent with previous incidents involving other aircraft of the same type.
Findings
- The primary cause of the structural damage was the intensive use of the aircraft for flight training, which accelerated the fatigue wear of the airframe structure.
- Significant taxiing on unpaved surfaces contributed to the stress on the landing gear and firewall components.
- The design and structural characteristics of the airframe were found to be inadequately suited for high-intensity training operations on uneven terrain.