What happened
On March 21, 2019, a Cessna AA188-B, registration LV-LNN, was performing agricultural spraying operations near Sachayoj, Santiago del Estero. After taking off from an improvised runway, the aircraft entered a left turn at an altitude of approximately 250 feet and a speed of 100 mph. During this maneuver, the engine experienced a drop in power, preventing the aircraft from maintaining its flight path.
The pilot attempted to level the wings and verified that the throttle was at full power, the propeller was in fine pitch, and the mixture was rich. Seeking an emergency landing site, the pilot directed the aircraft toward a wooded area and deployed full flaps. While attempting to activate the emergency hopper release, the left wing struck a tree, causing the aircraft to lose control and crash into the ground. The pilot sustained one minor injury, and there were no fatalities.
The investigation
Investigators examined the wreckage and found significant damage to the aircraft, including the hopper and both fuel tanks, which resulted in the loss of all contents. The engine, a Continental IO-520-D, was sent to an aeronautical workshop for a detailed inspection.
Technical analysis of the engine's internal and external components revealed no evidence of mechanical failure or malfunction. Furthermore, physical evidence from the crash site, specifically the marks left by the propeller on the trees, confirmed that the engine was still producing power at the moment of impact. The investigation also noted that the maintenance logs for the airframe, engine, and propeller were not up to date, with the last recorded intervention occurring in December 2018.
Findings
- The engine was delivering power at the time of the accident, and no technical cause for an engine failure was identified.
- The aircraft was operating at a weight very close to its maximum takeoff weight.
- The investigation could not definitively determine the primary trigger, leaving two possible scenarios: a sudden engine power loss during the climb phase, or improper management of airspeed, altitude, and bank angle leading to a loss of lift.
- Maintenance records for the engine, propeller, and airframe were outdated.
- The emergency hopper release system was not activated prior to the impact.