What happened
On March 17, 2017, a Cessna 208B, registration PT-OQT, was performing a cargo flight from Manaus to Carauari, Amazonas, when it experienced a runway excursion. The aircraft, operated by CTA - Cleiton Táxi Aéreo Ltda., landed at the Carauari Aerodrome (SWCA) with two crew members on board. During the landing roll, approximately 450 meters after touchdown, the aircraft veered off the left side of the runway. The incident resulted in light damage to the aircraft, but both crew members were uninjured.
The investigation
CENIPA investigators examined the aircraft's landing gear and found that the left main tire was deflated and deformed. The investigation also revealed that the nose gear fork had become detached, though the tire itself remained undamaged. Analysis of the left main tire's inner tube, conducted at the Institute of Aeronautics and Space (IAE), identified surface wear and two cuts; one of these cuts had caused the loss of pressure. While the exact cause of the cuts could not be definitively determined, the characteristics suggested the use of a sharp object, such as a screwdriver, which could indicate improper handling during maintenance.
Further investigation into the operator's maintenance records revealed significant discrepancies. The service order for the tire replacement listed a Michelin inner tube intended for the nose gear, yet a Goodyear brand tube was actually installed on the left main gear. Additionally, investigators found that the company's stock of inner tubes was significantly lower than its stock of tires, and there was no record of new tubes being issued from inventory. This led to the possibility that used inner tubes were being reused. The investigation also noted a lack of traceability, as maintenance records did not identify the specific personnel responsible for the assembly or disassembly of the landing gear components.
Findings
- Maintenance failures: The investigation could not definitively pinpoint the exact cause of the cuts, but identified a lack of traceability regarding the maintenance of wheel assemblies.
- Management oversight: A latent failure in managerial supervision regarding maintenance standardization and procedures allowed for the potential use of improper or reused components.
Safety action
CENIPA issued a recommendation to the National Civil Aviation Agency (ANAC) to ensure the operator implements an effective control mechanism for maintenance activities performed by its workshop, specifically regarding the disassembly, assembly, and replacement of landing gear wheel components.