What happened
On March 16, 1999, a Cessna 172-B, registration PT-BMI, departed from Pirassununga, São Paulo, bound for Ubatuba. The flight, which included the pilot and one passenger, began with a 20-minute low-altitude sightseeing tour over the departure city. Following this, the aircraft proceeded toward its destination.
At approximately 14:00, the engine failed while the aircraft was over the hilly terrain near Taubaté. Lacking sufficient altitude or power, the pilot attempted an emergency landing in an unprepared field. The aircraft's main gear struck the vegetation, creating a six-meter track before the plane struck several trees and a television antenna tower. The impact caused the aircraft to land in an inverted position, resulting in two fatalities (the pilot died instantly, and the passenger succumbed to injuries 2-4 weeks later).
The investigation
CENIPA's investigation revealed that the aircraft had been purchased by the pilot on the very day of the accident. The investigation focused on the engine's performance and the maintenance history of the carburetor. Investigators discovered that a maintenance workshop had issued a certificate claiming a general overhaul of the carburetor had been performed, but evidence showed the component had never actually been opened for inspection. Instead, the workshop had used improper domestic thread sealant and left excessive clearances in the carburetor rods. Furthermore, the investigation found that the pilot had not filed a flight plan and had failed to accurately calculate the fuel required for the trip, especially considering the high fuel consumption during the low-altitude portion of the flight.
Findings
- Fuel Exhaustion: The primary cause of the engine failure was the lack of fuel in the tanks, tanks which were not replenished before departure.
- Inadequate Planning: The pilot failed to account for the increased fuel consumption caused by flying at low altitudes with a rich mixture.
- Maintenance Irregularities: The aircraft's maintenance was found to be deficient, specifically regarding fraudulent documentation for carburetor servicing and damaged magneto wiring.
- Lack of Type Experience: Although an experienced pilot, the commander had no prior experience flying this specific aircraft model and had not received adequate transition training.
- Human Factors: High levels of motivation and anxiety regarding the new acquisition may have impaired the pilot's critical judgment and decision-making.