What happened
On October 7, 2016, a Neiva EMB-202 aircraft, registration PT-ULQ, was performing agricultural spraying operations at Fazenda Menina Linda in Ipiranga do Norte, Mato Grosso. During one of the application passes, the aircraft struck the ground, resulting in the destruction of the airframe and the fatal injury of the pilot.
The investigation
CENIPA investigators examined the wreckage and discovered that the left wing had separated from the fuselage and was located approximately 15 meters away from the main wreckage. Laboratory analysis of the left wing spar's lower flange revealed macroscopic signs of corrosion.
Technical analysis conducted by the Department of Aerospace Science and Technology (DCTA) determined that the wing failure was caused by a fatigue process within the lower flange of the spar. The fatigue crack had propagated through approximately 70% of the flange section, significantly reducing its mechanical strength and eventually leading to a final rupture due to structural overload. The investigation also noted that corrosion present on the fifth hole and the pin contributed to the initiation of the fatigue process.
Furthermore, the investigation reviewed the aircraft's maintenance history and found that the operator had failed to comply with Airworthiness Directive (AD) 2015-09-01. Although the aircraft had undergone an Annual Maintenance Inspection (IAM) in September 2016, the specific inspection procedures required by the AD—intended to detect corrosion and cracks in the wing spars and attachment elements—were not performed. Had the inspection been carried out, the fatigue and corrosion could have been identified before the structural failure occurred.
Findings
- Failure to comply with Airworthiness Directive 2015-09-01, which prevented the detection of structural degradation.
- Fatigue and subsequent structural rupture of the left wing spar due to pre-existing corrosion.