A Canadair CRJ-200 cargo plane of West Air Sweden was destroyed when it impacted remote terrain near Akkajaure, Sweden. Both pilots were killed.

The aircraft departed Oslo-Gardermoen Airport, Norway at 23:10 hours local time on a mail and package flight to Tromsø, Norway.

The take-off, departure and climb to cruising altitude, flight level 330, were performed according to normal procedures. The flight was uneventful until one minute and 20 seconds before the impact. The event started at 00:19:20 hrs, one hour and ten minutes into the flight in night time conditions of darkness without moonlight, clouds or turbulence. The lack of external visual references meant that the pilots were totally dependent on their instruments which consisted of three independent attitude indicators.

Suddenly a very fast increase in pitch was displayed on the left attitude indicator. The pilot in command, who was the pilot flying and seated in the left seat exclaimed a strong expression. The displayed pitch change meant that the pilot in command was subjected to a surprise effect and a degradation of spatial orientation. The autopilot was, most probably, disconnected automatically, a "cavalry charge" aural warning and a single chime was heard, the latter most likely as a result of miscompare between the left and right pilots' flying displays (PFD).

Both elevators moved towards nose down and nose down stabilizer trim was gradually activated from the left control wheel trim switch. The airplane started to descend, the angle of attack and G-loads became negative up to -1 G. Both pilots exclaimed strong expressions and the co-pilot said "come up".

About 13 seconds after the start of the event the crew were presented with two contradictory attitude indicators with red chevrons pointing in opposite directions. At the same time none of the instruments displayed any comparator caution due to the PFDs declutter function in unusual attitude.

Bank angle warnings were heard and the maximum operating speed and Mach number were exceeded 17 seconds after the start of the event, which activated the overspeed warning.

The speed continued to increase, a distress call was transmitted and acknowledged by the air traffic control and the engine thrust was reduced to flight idle.

The crew was active during the entire event. The dialogue between the pilots consisted mainly of different perceptions regarding turn directions. They also expressed the need to climb. At this stage, the pilots were probably subjected to spatial disorientation. The aircraft collided with the ground one minute and twenty seconds after the initial height loss.



Investigation revealed that the erroneous attitude indication on PFD 1 was caused by a malfunction of the Inertial Reference Unit (IRU 1). The pitch and roll comparator indications of the PFDs were removed when the attitude indicators displayed unusual attitudes. In the simulator, in which the crew had trained, the corresponding indications were not removed. During the event the pilots initially became communicatively isolated from each other.

Probable Cause:

Factors as to cause and contributing factors:

The accident was caused by insufficient operational prerequisites for the management of a failure in a redundant system.



Contributing factors were:

- The absence of an effective system for communication in abnormal and emergency situations.

- The flight instrument system provided insufficient guidance about malfunctions that occurred.

- The initial manoeuver that resulted in negative G-loads probably affected the pilots' ability to manage the situation in a rational manner.



Factors as to risk

The fact that fault descriptions regarding aircraft and its components are reported in a less detailed manner might imply that the faults will not be identified and corrected in an efficient way. This can in turn lead to a flight safety issue as, for instance, intermittent faults cannot always be detected by general tests.

Accident investigation:

Investigating agency: SHK Sweden Status: Investigation completed Duration: 11 months Accident number: SRL 2016:01e Download report: Final report

Classification:

Follow-up / safety actions

SHK issued 14 Safety Recommendations

Issued: 12-DEC-2016 To: ICAO RL 2016:11 R1 Ensure that a general system of initial standard calls for the handling of abnormal and emergency procedures and also for unusual and unexpected situations is implemented throughout the commercial air transport industry. (Closed - adequate response) Issued: 12-DEC-2016 To: Swedish Transport Agency RL 2016:11 R10 Ensure that the Maritime Administration secures that all crews maintaining preparedness for SAR missions in mountainous areas fulfil the requirements on capability to perform appropriate search tasks. Issued: 12-DEC-2016 To: Swedish Maritime Administration RL 2016:11 R11 Develop the coordination between the sea and air rescue coordination centre (JRCC) and concerned air traffic control units (including ATCC) so that air traffic control units staff becomes familiar with which facts and other information they may need to assist JRCC. (Closed - adequate response) Issued: 12-DEC-2016 To: Swedish Maritime Administration RL 2016:11 R12 Ensure that rescue commanders and assistant rescue commanders are given regular training and exercising in staff work with collaborators from other authorities responsible for rescue services and organisations in JRCC. Issued: 12-DEC-2016 To: Swedish Maritime Administration RL 2016:11 R13 Produce a basis for, and perform, training and exercising in searching in a mountainous environment for SAR crews maintaining preparedness in a mountainous environment in both daylight and darkness. Issued: 12-DEC-2016 To: Swedish Maritime Administration RL 2016:11 R14 Review procedures so as to minimise the time for preparations ahead of take-offs with SAR helicopters. Issued: 12-DEC-2016 To: EASA RL 2016:11 R2 Ensure that a general system of initial standard calls for the handling of abnormal and emergency procedures and also for unusual and unexpected situations is implemented throughout the commercial air transport industry. (Closed - adequate response) Issued: 12-DEC-2016 To: EASA RL 2016:11 R3 Ensure that the design criteria of PFD units are improved in such a way that pertinent cautions are not removed during unusual attitude or declutter modes. (Closed - adequate response) Issued: 12-DEC-2016 To: Transport Canada RL 2016:11 R4 Ensure that a general system of initial standard calls for the handling of abnormal and emergency procedures and also for unusual and unexpected situations is implemented throughout the commercial air transport industry. (Closed - adequate response) Issued: 12-DEC-2016 To: Transport Canada RL 2016:11 R5 Ensure that the design criteria of PFD units are improved in such a way that pertinent cautions are not removed during unusual attitude or declutter modes. (Closed - adequate response) Issued: 12-DEC-2016 To: FAA RL 2016:11 R6 Ensure that a general system of initial standard calls for the handling of abnormal and emergency procedures and also for unusual and unexpected situations is implemented throughout the commercial air transport industry. (Closed - adequate response) Issued: 12-DEC-2016 To: FAA RL 2016:11 R7 Ensure that the design criteria of PFD units are improved in such a way that pertinent cautions are not removed during unusual attitude or declutter modes. (Closed - adequate response) Issued: 12-DEC-2016 To: Swedish Transport Agency RL 2016:11 R8 Ensure that providers of air traffic control units guarantee procedures to enable an alerting message about a critical situation to be submitted immediately to the air rescue centre concerned. Issued: 12-DEC-2016 To: Swedish Transport Agency RL 2016:11 R9 Ensure that providers of air traffic control units train and exercise relevant personnel so that they can assist the air rescue centre in accordance with current regulations. Show all... SHK issued 14 Safety Recommendations

Photos



FDR Pitch Angle (blue) and preliminary calculated Pitch Angle (green). FDR Pitch Angle (blue) and preliminary calculated Pitch Angle (green).

SE-DUX SE-DUX

SE-DUX SE-DUX

accident date:

type: Canadair CRJ-200PF

registration: SE-DUX accident date:type: Canadair CRJ-200PFregistration: SE-DUX

Aircraft history

date registration operator remarks Jan 1993 C-GRJW Canadair first flight as CRJ-100ER 2 Feb. 1993 D-ACLE Lufthansa CityLine delivered D-ACLE Lufthansa CityLine modifed to CRJ-100LR 27 September 2006 C-FJGI Bombardier registered 2007 C-FJGI Bombardier converted to CRJ-200PF cargo version 14 May 2007 SE-DUX West Air Sweden registered

Map

not display the exact flight path.

Distance from Oslo-Gardermoen Airport to Tromsø/Langnes Airport as the crow flies is 1107 km (692 miles).

Accident location: Exact; as reported in the official accident report. This map shows the airport of departure and the intended destination of the flight. The line between the airports doesdisplay the exact flight path.Distance from Oslo-Gardermoen Airport to Tromsø/Langnes Airport as the crow flies is 1107 km (692 miles).Accident location: Exact; as reported in the official accident report.

This information is not presented as the Flight Safety Foundation or the Aviation Safety Networks opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.