What happened
On April 19, 2016, a Cessna 152, registration PR-ADD, operated by Aeroclube de Ponta Grossa, departed Ponta Grossa Airport (SSZW) for a local test flight. The flight was intended to verify engine parameters following recent maintenance on the aircraft's magnetos. The aircraft was flying without a filed flight plan.
While returning to the airport at an altitude of approximately 4,50 and feet, the pilot experienced intense vibrations through the control column, which made maintaining aircraft control increasingly difficult. Unable to reach the runway, the pilot executed a forced landing in a soybean plantation in a rural area of Ponta Grossa. The pilot and the passenger both escaped the incident without injury, and the aircraft sustained no damage.
The investigation
CENIPA investigators examined the aircraft's control system and maintenance records. Upon inspection of the wreckage, investigators discovered that a bolt, nut, and cotter pin—essential components of the elevator trim compensator system—were missing. It was determined that this hardware assembly had detached during flight.
An analysis of the actuator rod and linkage revealed areas of superficial corrosion caused by discontinuities in the protective paint. While this corrosion had not caused significant material loss or mechanical play, it was noted as a factor in the hardware's condition. Furthermore, the investigation found that the aircraft's maintenance logs for the airframe, engine, and propeller were not up to date, with significant gaps in hour entries dating back to 2013. Additionally, the weight and balance documentation provided was incomplete, preventing a definitive calculation of the aircraft's center of gravity at the time of the event.
Findings
- Maintenance and management oversight regarding the inspection and upkeep of the elevator trim system.
- Fragile operational procedures at the flight club regarding maintenance standardization and pre-flight inspections.
- Presence of superficial corrosion on the control rod due to inadequate paint protection.
- Incomplete maintenance record-keeping for the aircraft's primary components.
- The detachment of the bolt, nut, and cotter pin from the elevator trim compensator system during flight.