What happened
On July 7, 2013, a Bell 206B helicopter, registration PT-HCH, was performing a series of flight legs to transport guests to a private event in the state of São Paulo. During the final leg of a sequence of flights conducted without intermediary refueling, the pilot noticed the fuel pump light illuminate, followed immediately by an engine flameout.
The pilot initiated an autorotation procedure over a pasture area. During the landing attempt, the aircraft struck the irregular terrain with a high rate of descent. The impact was followed by a collision with a wire fence, which severed the tail boom. The helicopter tumbled onto its right side and skidding approximately ten meters before coming to a rest. The accident resulted in one serious injury and two minor injuries among the passengers and crew, while one passenger remained unhurt. The aircraft sustained substantial damage to the fuselage, rotors, landing gear, and cabin.
The investigation
CENIPA investigators focused on determining the cause of the engine flameout and the circumstances leading to the hard landing. Technical inspections of the aircraft revealed that the fuel pumps and the fuel gauge were functioning correctly, ruling out mechanical failure. However, testing confirmed that the remaining fuel in the tanks was less than 10 US gallons.
According to the Aircraft Flight Manual (AFM), 10 US gallons is considered unusable fuel due to potential sloshing or pump inoperability. The investigation established that approximately 3 hours and 20 minutes of flight time had elapsed since the last refueling, and the pilot had been monitoring fuel levels solely via the gauge without accounting for the hourly consumption rate. Furthermore, the investigation examined the pilot's experience level and the operational planning regarding the flight sequence.
Findings
- Fuel exhaustion was the primary cause of the engine flameout.
- The pilot's lack of experience in this specific aircraft type (having fewer than 10 hours) contributed to poor flight planning and a failure to monitor fuel consumption against time elapsed.
- Inadequate flight planning resulted in the pilot relying exclusively on the fuel indicator without calculating the remaining endurance based on the 95–100 liters per hour consumption rate.
- The pilot's application of controls during the autorotation was likely inappropriate, leading to the high rate of descent and the subsequent hard impact.
- There was a lack of managerial oversight, as the operator did not adequately evaluate the need for refueling between the multiple flight legs performed over the weekend.