What happened
On October 12, 2016, a Neiva EMB-810D, registration PT-RVM, departed from a farm in Manacapuru, Amazonas, en route to Boa Vista, Roraima. The flight was intended to transport personnel, with a single pilot on board. During the flight, approximately 110 NM from the destination, the pilot experienced abnormal vibrations in the right engine, accompanied by a drop in oil pressure and an increase in engine temperature.
Due to the worsening vibration and engine instability, the pilot decided to perform an emergency landing at a dirt runway on Fazenda Novo Para验íso, near Caracaraí. During the final approach, the pilot maintained a speed of approximately 95 knots, which was 10 knots above the manual's recommended speed. To avoid holes in the center of the runway, the pilot landed on the right side of the strip. The aircraft subsequently drifted off the runway, struck bushes, and the left landing gear struck a hole in the terrain. This impact caused the aircraft to rotate 180 degrees and resulted in the landing gear being retracted into the airframe. The aircraft sustained substantial damage, though the pilot remained uninjured.
The investigation
CENIPA investigators examined the right engine (Continental LTSIO-360-KB2) and fuel samples. While fuel tests confirmed the fuel met all regulatory specifications, the investigation revealed several mechanical discrepancies. The right magneto was found to be inoperable due to a failed capacitor, and the left magneto showed deficient spark performance. Additionally, the fuel pump was operating at pressures below the required manual specifications, and there was a lack of fuel return.
Further analysis of the engine cylinders showed evidence of operating with a lean mixture, which likely caused overheating and potential pre-ignition or detonation. Investigators also discovered an unauthorized air filter installed in the injector nozzle pressurization tube that was not part of the manufacturer's maintenance manual. The investigation also noted that the aircraft's flight log was not available during the initial phase of the inquiry.
Findings
- Maintenance of the aircraft was a contributing factor, specifically regarding the degraded state of components like the magneto and fuel pump which did not match recent maintenance records.
- The pilot did not file a flight plan or check meteorological conditions prior to departure.
- The pilot's decision to fly at a low altitude (3,500ft) may have limited options, as a higher altitude might have allowed for a safer diversion to an airport with better runway conditions.
- The approach speed was 10 knots above the recommended manual speed.
Safety action
It is recommended that the National Civil Aviation Agency (ANAC) coordinate with the maintenance facility involved to verify the compliance of services performed by that workshop, ensuring the organization maintains the required levels of competence and operational safety.