What happened
On 11 May 2020, an AS350 B2 helicopter, registration PR-SCL, was operating a personnel transport flight from Belém to Breves, Pará, Brazil. The crew, which included two pilots, a special-equipment operator, and one passenger, was conducting a mission in support of COVID-19 pandemic response efforts.
While flying under Visual Flight Rules (VFR), the aircraft entered Instrument Meteorological Conditions (IMC) after flying above a cloud layer. To regain visual references, the pilot-in-command initiated an abrupt maneuver consisting of a descending right turn. During this maneuver, the main rotor speed increased to 4/93 RPM, exceeding manufacturer limits. This overspeed event caused high vibrations and triggered the automatic activation of the Emergency Locator Transmitter (ELT). The aircraft eventually stabilized and proceeded to its destination, sustaining minor damage to the main-rotor blade frequency adapters.
The investigation
CENIPA's investigation focused on the pilot's decision-making and the execution of the maneuver. Investigators examined the flight logs, meteorological charts, and the crew's actions. The investigation established that while the pilots were qualified and held valid medical certificates, they did not possess Instrument Flight Rules (IFR) ratings. The investigation also looked into the organizational culture of the operator, noting that the pilot-in-command acted unilaterally without coordinating the descent with the second-in-command.