What happened
On January 14, 2022, at approximately 10:00 UTC, an EMB-202 aircraft, registration PT-UPG, was performing agricultural spraying operations over a sugarcane plantation at Fazenda Aliança, in Cafelândia, São Paulo. During the flight, the left wing detached from the fuselage, causing the aircraft to lose control and collide with the ground. The impact resulted in fatal injuries for the pilot and caused substantial damage to the aircraft, including the separation of the right wing and landing gear due to the force of the impact.
The investigation
CENIPA investigators examined the wreckage and identified that the left wing separated from the fuselage during flight. Technical analysis of the fracture surfaces revealed beach marks, which are characteristic of fatigue cracking. The investigation established that the failure originated at the fifth 1/2-inch bolt position on the wing spar's lower flange. The process of fatigue-corrosion led to cracks propagating through all the plates of the lower flange, significantly reducing its mechanical strength and eventually causing a final rupture due to structural overload.
Furthermore, the investigation uncovered significant discrepancies in the aircraft's maintenance records. The aircraft's flight hour logs were outdated, and there were no evidence of the required 50-hour inspections being performed. While recent 100-hour inspections and airworthiness certificates were present, the advanced state of corrosion and multiple cracks found in the wing spar raised serious doubts regarding the quality and effectiveness of previous maintenance tasks and the adherence to mandatory Service Bulletins.
Findings
- The separation of the left wing was caused by a fatigue-corrosion process on the lower flange of the wing spar.
- Inconsistent aircraft records led to the underreporting of flight hours, which compromised the effective control and planning of scheduled maintenance inspections.
- There was a lack of effective maintenance oversight, as evidenced by the advanced corrosion and cracks found in the wing structure.
- Management and administrative non-conformities, specifically regarding flight log accuracy and operational safety management, prevented the timely identification of latent unsafe conditions.
- Maintenance quality was questionable, with doubts raised regarding the actual execution of required inspections and Service Bulletins.