Flight Details
Widerøe flight 710 departed Trondheim (TRD), Norway, at 19:23 local time with planned stops at Namsos (OSY), Brønnøysund (BNN), Sandnessjøen (SSJ), and Bodø Airport (BOO). The leg to Namsos was uneventful. After taking off from Namsos at 20:07, the crew contacted Trondheim ACC six minutes later, reporting a climb from FL70 to FL90. At 20:20, they began descent for Brønnøysund and switched frequencies to Brønnøysund AFIS.
Weather and Approach
The weather reported at Brønnøysund was: wind 220°/05 kts, visibility 9 km, 3/8 stratus at 600 feet and 6/8 at 1000 feet, temperature +6°C, QNH 1022 MB. The crew performed a VOR/DME approach to runway 04, followed by a circling approach to land on runway 22.
Accident Sequence
During the approach, the crew left the prescribed altitude 4 NM early. The aircraft descended and struck the Torghatten hillside at an elevation of 560 feet.
Mobile Phone Investigation
In July 2013, a retired police officer reported that a passenger had brought a mobile phone on board. The officer, who disembarked at Namsos, stated that the passenger with the phone was seated in the cockpit jump-seat. He reported this to the Joint Rescue Coordination Centre (JRCC) after the accident. During the 25th anniversary, he noted that the investigation report did not mention the phone. NMT 450 network-based mobiles at the time had a 15-watt transmitter and powerful battery, which could potentially disrupt electronic equipment. The Norwegian AIB investigated whether electronic interference from the mobile phone affected flight instruments, but concluded there was no evidence of any interference.
Probable Cause
The official finding stated: "The cause of the accident was that the last part of the approach was started about 4 NM too soon. The aircraft therefore flew below the safe terrain clearance altitude and crashed into rising terrain. The Board cannot indicate any certain reason why the approach started so early."