What happened
On July 1, 2020, a Cessna A188B, registration HK-1997, was conducting agricultural spraying operations over a rice crop at Finca Venecia, near Fundación, Magdalena. The aircraft had departed from La Palestina airfield to perform the day's first scheduled flight.
Approximately eight minutes into the flight, while the pilot was descending to begin spraying the field, the engine experienced a significant reduction in power. At an altitude of approximately 100 feet, the pilot initiated emergency procedures and executed a controlled forced landing in an unprepared field located about 250 meters from the intended target area.
The impact with the uneven terrain caused the left main landing gear to detach and resulted in extensive damage to the airframe, including the fuselage, wings, flaps, ailerons, and the spraying boom system. The pilot sustained minor injuries and was able to exit the aircraft unassisted. No post-crash fire occurred.
The investigation
The GRIAA investigation focused on the engine's performance and the mechanical state of the powerplant. Investigators examined the Continental IO-520-D113B engine and its accessories. The inspection revealed that the number 4 main support bearing had shifted from its original position, causing significant material loss on both the crankshaft and the engine crankcase. This displacement led to the obstruction of the lubrication lines, resulting in increased temperatures and a drop in oil pressure.
Findings
- The primary cause of the engine failure was the wear and displacement of the number 4 support bearing, which blocked the lubrication passages.
- The bearing displacement was likely caused by engine assembly inaccuracies or misalignments occurring during a previous overhaul or during regular operation.
- The pilot's focus on configuring the aircraft for the emergency landing prevented him from noticing specific instrument indications during the power loss.
- The aircraft sustained substantial structural damage due to the landing on unprepared terrain.