What happened
On April 14, 2018, a Cessna 152, registration PR-TXH, was conducting a specialized aerial advertising flight near Ipatinga, Minas Gerais. The mission involved flying at low altitudes near the local municipal stadium to broadcast audio via external devices. After departing from Aeródromo Aerovaço (SJWA), the aircraft had been in flight for approximately seven minutes when the pilot reported engine parameter oscillations, followed by a total engine failure.
During the emergency procedure to perform a forced landing in an open area near the intersection of highways BR 458 and BR 381, the aircraft's left wing struck a public lighting pole. This impact caused a loss of control, resulting in the aircraft striking the ground in an inverted position. The aircraft sustained substantial damage, and the pilot sustained serious injuries.
The investigation
CENIPA investigators examined the engine and the fuel supply chain. Analysis of the engine by the Department of Aerospace Science and Technology (DCTA) revealed metal shavings in the oil filter and crankcase, as well as significant wear on the piston plug of cylinder number one. Additionally, cracks and discoloration were found on the intake valves of cylinders one and two, indicating operation at high temperatures.
While these mechanical discrepancies were present, investigators determined they were insufficient to cause the immediate engine failure. Instead, the investigation focused on the fuel used for the flight. Samples taken from the aircraft's tanks and the storage containers at the contracting company's site were analyzed. Of the four samples taken from the storage canisters, three were found to contain water, with only one meeting the required aviation gasoline standards.
Furthermore, the investigation found that the fuel was being stored in plastic containers, which violates the ABNT NBR 15216 standard requiring the use of stainless or carbon steel. The company also lacked a formal quality control process for fuel sampling.
Findings
- The engine failure was likely caused by water contamination in the fuel.
- Fuel storage practices at the contracting company failed to comply with safety standards, specifically regarding the use of improper plastic containers and the lack of periodic quality testing.
- Ineffective management supervision regarding the technical and operational planning of the aerial advertising services contributed to the lack of fuel quality control.