What happened
On August 4, 2008, at approximately 18:09 UTC, a Cessna 182F, registration OB-1229, operated by Aero Negocios JLE, departed from Pucallpa's David Abenzur Rengifo Airport bound for Contamana. The flight was carrying one pilot and four passengers.
Roughly 30 minutes into the flight, while over the Holanda settlement, the aircraft experienced a mechanical failure. The pilot declared an emergency and performed an engine-off landing on the banks of the Ucayli River, approximately 14.4 nautical miles from Contamana. Despite the impact, all 5 occupants escaped the aircraft without injury. The aircraft sustained structural damage to the lower fuselage, including a broken nose gear mounting, a detached right-side cowl flap, and a bent propeller blade.
The investigation
The CIAA investigation focused on the Teledyne Continental O-470-R engine. Upon inspection, investigators found an oil leak on the rocker cover of cylinder number one and a broken cylinder head cover. Further examination revealed that the exhaust rocker arm was not making contact with the valve, but rather with the rotocoil.
Testing showed that cylinder number one had no compression, while the remaining five cylinders functioned normally. Removing the lower spark plug from cylinder number one revealed metal particles, and a hole was discovered in the piston. Additionally, an oil leak was noted at the carburetor.