Report on aviation accident in Uvdal on 18 March 2019 involving Robinson R44, LN-OGT
Aviation report 2020/05
The aviation accident occurred on Monday 18 March 2019. The helicopter was parked on a landing site with a marginal size. When the helicopter hovered, about 1 m above the ground, the commander experienced the helicopter as unstable. The helicopter rotated to the right, which the commander attempted to compensate by pressing the left pedal unsuccessfully. He chose to set the helicopter down. When the helicopter was on the ground it rotated to the left, thereby the tail boom hit a snow drift. The tail rotor and vertical fin sustained damage. The commander was uninjuried. Based on the meteorological information, the Accident Investigation Board Norway finds it likely that variable and strong downdrafts may have occured in the terrain around Uvdal during the period of the aviation incident.
It cannot be excluded that wind speed and wind direction resulted in Loss of Tail rotor Effectiveness (LTE). The unexpected crosswind also probably caused the helicopter to drift far enough to the right causing tail rotor blade contact with the snow when the commander chose to cancel the departure and land the helicopter. The AIBN considers that the chosen landing area gave small margins in relation to wind and turbulence. It may seem that helicopters are increasingly used for recreational purposes, and that the importance of choosing suitable landing sites not always are taken into account.
This report is in Norwegian only.
No safety recommendation is issued in connection with this investigation.
Facts
| Location | Uvdal ski centre, Uvdal in Buskerud county, Norway |
| Occurrence date | 18.03.2019 |
| Aircraft | Robinson R44 |
| Operator | Private |
| Registration | LN-OGT |
| Meteorological conditions | VMC |
| County | Viken |
| Type of occurrence | Accident |
| Type of operation | Private |
| Category of operation | Light, helicopter (<= 2 250kg) |
| Aircraft category | Helicopter, Single-engine, Piston engine |
| FIR/AOR | ENOS (Oslo ATCC) |