What happened
On April 19, 2022, a PA-46-600TP, registration PS-RJJ, was performing a private flight from Porto Belo, Santa Catarina, to Primavera do Leste, Mato Grosso. While cruising at flight level 280, the pilot observed abnormal variations in fuel flow, which were followed by an engine failure and subsequent cabin depressurization.
In response to the engine malfunction, the pilot initiated an emergency descent and performed an in-flight restart attempt. After being unable to restore power, the pilot executed an emergency landing at the Governador José Richa Aerodrome in Londrina, Paraná. The aircraft sustained minor damage to the internal engine components, and the pilot was uninjured.
The investigation
CENIPA investigators examined the engine and fuel systems to determine the cause of the power loss. Laboratory analysis of the fuel line connecting the Fuel Control Unit (FCU) to the Fuel Flow Meter revealed a crack near the connection to the meter. Microscopic examination identified characteristics of high cycle fatigue (H/CF) that led to the fuel leak.
Investigators also examined the engine's power section, finding evidence of a seized turbine and damage consistent with exposure to excessive heat. The investigation focused on the relationship between the fuel leak and the pilot's actions during the emergency. Additionally, the team inspected the metallic ferrule of the fuel line, noting a deformation that may have created the stress concentration necessary to trigger the fatigue process.
Findings
- A crack in the fuel line caused a leak, leading to the initial engine failure.
- The crack was the result of high cycle fatigue (HCF) caused by stress concentration.
- The deformation in the fuel line ferrule may have been caused by the displacement of the tube during a maintenance procedure on the fuel pump outlet filter.
- Rapid movement of the Manual Override Regulator (MOR) lever during the emergency caused spikes in Interstage Turbine Temperature (ITT) and fuel flow, leading to engine component damage and seizure.
- The pilot's handling of the flight controls during the emergency exacerbated the consequences of the failure.