What happened
On May 25, 2012, at approximately 20:45 UTC, a Cessna 150H, registration PT-DFZ, was conducting a flight training navigation mission from Umuarama to Cascavel, Paraná. The flight was part of the Private Pilot License (PPL) training program. After 40 minutes of flight, as the crew began descending from FL045 to a traffic altitude of 3,500 feet, the engine experienced a partial power loss, with RPM dropping from 2,500 to 1,400. Unable to restore power, the instructor executed an emergency landing on an asphalt road near the Espigão Azul district. Both occupants of the aircraft escaped without injury, and the aircraft sustained no damage.
The investigation
CENIPA investigators examined the aircraft's maintenance records and conducted engine tests the day following the occurrence; these tests revealed no mechanical abnormalities. The investigation focused on environmental conditions and flight planning. At the time of the incident, the region was experiencing low temperatures and high humidity. Meteorological data from Cascavel (SBCA) indicated a dew point of 11 degrees Celsius against an ambient temperature of 18 degrees Celsius, suggesting conditions conducive to carburetor icing. Additionally, the investigation noted that the aircraft was operating outside of its weight and balance limits, with a total weight of 1,717.6 lbs.
Findings
- Carburetor icing was identified as a likely cause due to the high humidity and low temperatures present during the flight.
- Inadequate flight planning contributed to the occurrence.
- Pilot judgment regarding the operational environment contributed to the incident.