What happened
On December 14, 2014, an Airbus Helicopters AS 350 B3, registration LN-OWE, was conducting an aerial work mission to transport equipment for a mobile base station near Flatøy, Meland. The mission involved flying a GSM cabinet as underslung load to a mast location and returning with old equipment. Prior to the flight, the pilot and loadmaster had inspected the landing site via ground vehicle, noting the area was somewhat tight but manageable, bounded by a power line, a wall, and concrete elements.
During the approach, the pilot performed a reconnaissance flight to assess the site. While approaching from the west into a headwind, the pilot observed a person standing in an unfavorable position on the landing area. To maintain a safe distance from this individual, the pilot continued the approach. As the aircraft descended to approximately 2 meters above the ground, the tail rotor struck a stack of concrete elements that had been placed like steps. The impact caused high-frequency vibrations and a noticeable strike. The pilot immediately increased altitude and moved forward to clear the obstacle before completing the landing safely. There were no injuries to the three occupants.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the landing site, the aircraft, and the flight conditions. The investigation confirmed that the landing area met the operator's size requirements of approximately 20 by 20 meters. Investigators also attempted to retrieve data from an onboard Appareo Vision 1000 cockpit recorder to review video of the event; however, the memory card was found to be missing data from the flight in question, and the internal memory could not be recovered.
Findings
- The primary cause of the incident was the tail rotor striking concrete obstacles while the pilot was focused on maintaining distance from a person on the landing pad.
- The pilot's attention was likely diverted by the presence of the individual on the ground, which reduced situational awareness regarding the proximity of the tail rotor to the concrete elements.
- The pilot's prior inspection of the site may have created a false sense of security, leading to decreased vigilance during the actual landing.
- Reduced visibility due to increasing rainfall during the approach may have further contributed to the lack of obstacle detection.
- There was no established communication between the flight crew and personnel on the ground at the time of the approach.