What happened
On April 17, 2018, a Bell 407 helicopter, registration PT-YZJ, was conducting a shuttle flight from Campo Grande Aerodrome to Hercílio Luz Aerodrome. The aircraft was carrying two crewmembers and two passengers, including a maintenance mechanic.
While approximately 15 nautical miles from Maringá, the crew heard a loud noise emanating from the engine. The pilot-in-command initiated a precautionary landing in an unprepared field. During the descent, at an altitude of approximately 200 feet, the engine suffered a flameout. The crew performed an autorotation to land the aircraft. The impact resulted in substantial damage to the engine, tail rotor driveshaft, tail cone fairing, and finlets, as well as minor damage to the main rotor blades. All four occupants of the aircraft escaped the occurrence unharmed.
The investigation
CENIPA's investigation focused on the engine's mechanical condition and maintenance history. Investigators examined the Rolls-Royce Model 250-C47B engine and found that while a manufacturer service bulletin (CEB 72-5058) regarding bearing no. 2 had been implemented, another recommended update (CEB 72-6081) regarding the replacement of the oil injector (piccolo tube) had not been performed.
Furthermore, the investigation revealed that less than eight hours after an oil change, the engine chip light had illuminated, indicating the presence of metallic particles. Despite this, the aircraft was released for flight, in violation of established manufacturer procedures. The investigation also looked into the organizational structure of the Federal Highway Police (PRF), noting a lack of effective information flow regarding flight safety and management oversight.