What happened
On April 4, 2016, a Cessna 208B, registration PR-CRF, operated by TWO Táxi Aéreo Ltda., was performing a cargo and passenger flight from Alberto Alcolumbre International Airport (SBMQ) to Monte Dourado (SBMD). During the initial climb, at approximately 1,800 feet, the aircraft suffered a sudden loss of power followed by a complete engine flameout.
The crew attempted to restart the engine without success. Consequently, the pilot performed an emergency landing in an unprepared field located approximately 3NM from the runway 08 threshold of SBMQ. During the landing roll, the aircraft traveled about 10 and 100 meters before the nose gear separated from the airframe. The impact caused substantial damage to the propeller, engine, nose gear, and right wing. While most occupants were uninjured, one passenger sustained minor injuries.
The investigation
CENIPA investigators examined the engine components, specifically the fuel pump and the Fuel Control Unit (FCU), through bench testing at a certified maintenance facility. These tests confirmed that both components were functioning within manufacturer limits and ruled out fuel supply failure from these units.
Further inspection of the engine revealed that a fuel transfer tube near the 4 o'clock position of the igniter was displaced from its proper seat. Investigators found that the retaining plate for the transfer tubes had been deformed. This deformation was traced back to the improper anchoring of the igniter cable safety wire. The investigation determined that the high fuel pressure in that area caused the displaced tube to move, creating a leak at the conical seat of the injector nozzle, which led to the loss of engine power.
Findings
- Improper maintenance: The deformation of the retaining plate was caused by excessive tension applied to the igniter cable safety wire during maintenance tasks performed the previous day (a compressor wash). This improper anchoring allowed the fuel transfer tube to move under operating pressure.
- Inadequate management supervision: The failure to identify the improper safety wire anchoring and the resulting plate deformation during post-maintenance inspections indicated a lack of adequate technical supervision of maintenance activities.