Report on serious incident at Bryne in Rogaland county, Norway, 25 October 2022 with Airbus Helicopters AS 350B3, LN-OGN operated by Helitrans AS
Aviation report 2024/01
The Commander experienced what he believed to be Pilot-induced oscillations (PIO) when stringing lines through power line pylons. The helicopter became uncontrolable and hit a high-voltage mast so that the right skid was bent. The Commander released the cargo line and the tool, regained control of the helicopter and landed.
When the phenomenon of PIO is mentioned in connection with helicopters, the term Rotorcraft Pilot Coupling (RPC) is often used. RPC can be divided into two subgroups. PIO where the pilot contributes with active steering commands and PAO (Pilot-assisted oscillations) where the pilot gives unintended steering commands because he is influenced by the helicopter's movements. It cannot be definitively determined whether abrupt maneuvering by the Commander and/or contact between the tool and the mast triggered the RPC.
Relatively high friction on the collective reduces the likelihood of RPC occurring in a helicopter.
Published 19.01.2024
Facts
| Location | Bryne (11 NM south of Stavanger airport Sola (ENZV)), Norway |
| Occurrence date | 25.10.2022 |
| ICAO Location indicator | ENZV |
| Aircraft | Airbus Helicopter AS 350 B3 Ecureuil |
| Operator | Helitrans AS |
| Registration | LN-OGN |
| Meteorological conditions | VMC |
| County | Rogaland |
| Type of occurrence | Serious incident |
| Type of operation | Commercial, other |
| Category of operation | Light, helicopter (<= 2 250kg) |
| Aircraft category | Helicopter, Single-engine, Turboprop/turboshaft |
| FIR/AOR | ENSV (Stavanger ATCC) |