What happened
On October 12, 2004, a Cessna 150G, registration PT-LMR, was conducting a navigation training flight from Guarapari, ES, toward Conselheiro Lafaiete, MG. The flight crew, consisting of an instructor and a student, had previously completed a leg to Viçosa, MG, without incident.
Approximately three minutes before reaching the destination, the engine began to lose power. The instructor reported that the engine RPM dropped to approximately 2,000, significantly below the expected 2,500 RPM for full throttle. Despite the crew performing all prescribed emergency checklist procedures, the power loss could not be rectified. Due to the inability to maintain level flight, the instructor executed an emergency landing in an unprepared rural area. During the landing roll, the aircraft nose-over, resulting in severe damage to the propeller, left wing, landing gear, and right wing tip. Both the instructor and the student were uninjured.
The investigation
CENIPA's investigation focused on the cause of the engine failure and the operational legality of the flight. Technical analysis of the engine conducted by a specialized workshop found no evidence of mechanical defects or internal failures that would justify the loss of power. Investigators also examined meteorological data from nearby Barbacena, which indicated low ceilings and light rain, contradicting the crew's assertion that weather conditions were suitable for VFR flight.
Findings
- Flight indiscipline: The flight was conducted illegally as the instructor's medical certificate (CCF) had expired, and the operating organization was not authorized to provide practical flight instruction.
- Adverse weather conditions: Evidence suggests the flight may have been operating in weather conditions that were not suitable for VFR, potentially leading to carburetor icing due to high humidity and reduced power settings.
- Inadequate flight planning: The crew lacked updated meteorological information for the route and destination prior to departure.
- Engine failure: While the engine failed in flight, no mechanical cause was identified during post-accident testing.