Report on serious aviation incident in Kongsvikdalen, Tjeldsund municipality in Troms og Finnmark county 20 November 2021 involving Airbus Helicopters MBB-BK117 D-2, LN-OOS, operated by Norsk Luftambulanse AS
Aviation report 2022/10
On Saturday 20 November 2021, a helicopter from the air ambulance service was out to help three persons that were lost in the mountains. The helicopter had to wait in heavy snow showers while boarding the passengers. The crew were aware of a powerline they had to be carefull to avoid while navigating out of the valley. Due to the heavy snow the crew had issues locating the poweline. As they were hovering and searching for the powerline one of the engines suddenly stopped. The crew landed safely immediately, and shortly after landing the other engine also stopped. Nobody was injured in the incident. The investigation has found that the engines stopped due to ice in the air induction system that could enter the engine unhindrerd.
The investigation and tests after the incident have not found any technical fault with the engines that could have caused the shutdowns. The ice probably built up in the Inlet Barrier Filter (IBF) system while the helicopter was waiting for the party in distress. The IBF system is an optional and removable dust and particle filter that replaces the standard air inlet.
The weather conditions that can cause ice build-up are Norwegian winter conditions along the coast with temperatures of around zero degrees centigrade and high humidity.
The helicopter type has two configurations for the air intake and the safety issue is only for the IBF-system. Airbus Helicopters Deutschland have started the process of correcting this safety issue.
Published 15.11.2022
Facts
| Location | Kongsvikdalen, Troms og Finnmark, Norway |
| Occurrence date | 20.11.2021 |
| Aircraft | Øvrige helikoptre |
| Operator | Norsk Luftambulanse AS |
| Registration | LN-OOS |
| Meteorological conditions | VMC |
| County | Troms og Finnmark |
| Type of occurrence | Serious incident |
| Type of operation | Commercial, other |
| Category of operation | Heavy, helicopter (> 2 250kg) |
| Aircraft category | Helicopter, Multi-engine |
| FIR/AOR | ENBD (Bodø ATCC) |