What happened
On May 6, 2018, at approximately 18:00 UTC, a Robinson R22 Beta helicopter, registration PR-ACF, was performing a passenger transport flight in Quarto Centenário, Paraná. The flight originated from a local football field, where the aircraft had previously landed to pick up a passenger.
Shortly after takeoff, while executing a 180-degree turn, the pilot experienced intense vibrations. Upon checking the instruments, the pilot observed that both the engine and rotor RPM readings were approaching the redline limits. In an attempt to manage the situation, the pilot initiated an emergency landing by pulling the collective. However, the aircraft lost control, struck the ground, and overturned to the left. Both the pilot and the passenger survived the impact without injuries, though the aircraft sustained substantial damage.
The investigation
CENIPA investigators examined the aircraft and the pilot's operational history. While the pilot held valid medical and flight certifications, the investigation noted that the pilot had limited experience with this specific aircraft model, having completed rotary-wing training only in late 2017 and possessing approximately 50 flight hours on the R22.
The aircraft was found to be within weight and balance limits and possessed a valid Certificate of Airworthiness. Functional tests performed on the engine following the accident showed normal operation with no mechanical anomalies. However, investigators discovered that the overspeed governor switch was in the 'off' position. According to the Pilot's Operating Handbook (POH), this switch should be turned on during the pre-start checklist and remain on throughout the entire flight. The pilot indicated that he may have accidentally bumped the switch into the off position.
Findings
- The accidental disabling of the overspeed governor switch allowed the RPM to exceed safe limits.
- The pilot's limited experience with the R22 model contributed to the loss of control.
- Improper control inputs during the emergency maneuver contributed to the aircraft striking the ground and overturning.