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JS32, Torsby Sweden, 2014

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Summary
On 31 January 2014, an Estonian-operated BAE Jetstream 32 being used under wet lease to fulfil a government-funded Swedish domestic air service requirement landed long at night and overran the end of the runway. The Investigation concluded that an unstabilised approach had been followed by a late touchdown at excessive speed and that the systemic context for the occurrence had been a complete failure of the aircraft operator to address operational safety at anything like the level appropriate to a commercial operation. Failure of the responsible State Safety Regulator to detect and act on this situation was also noted.
Event Details
When January 2014
Actual or Potential
Event Type
HF, RE
Day/Night Night
Flight Conditions On Ground - Normal Visibility
Flight Details
Aircraft BRITISH AEROSPACE Jetstream 32
Operator Avies AS
Domicile Estonia
Type of Flight Public Transport (Passenger)
Origin Stockholm/Arlanda
Intended Destination Torsby Airport
Flight Phase Landing
LDG
Location - Airport
Airport Torsby Airport
General
Tag(s) Approach not stabilised
Inadequate Aircraft Operator Procedures
Ineffective Regulatory Oversight
Approach Unstabilised after Gate-no GA
Copilot less than 500 hours on Type
Unplanned PF Change less than 1000ft agl
HF
Tag(s) Plan Continuation Bias
Procedural non compliance
Ineffective Monitoring - SIC as PF
RE
Tag(s) Overrun on Landing
Directional Control
Excessive Airspeed
Late Touchdown
Excessive Exit to Taxiway Speed
Outcome
Damage or injury No
Causal Factor Group(s)
Group(s) Aircraft Operation
Safety Recommendation(s)
Group(s) Aircraft Operation
Investigation Type
Type Independent

Description

On 31 January 2014, a BAE Jetstream 32 (ES-PJR) being operated by Estonian airline Avies AS on a scheduled domestic passenger flight (AIA 205D) from Stockholm Arlanda to Torsby ran off the end of the destination runway after touchdown on the snow covered runway at night in normal ground visibility. There were no injuries to the passengers and no known damage to the aircraft.

The aircraft after the excursion. Reproduced from the Official Report.

Investigation

An Investigation was carried out by the Swedish Accident Investigation Authority (SHK). An Interim Statement on its progress was published on 30 January 2015.

It was established that the Estonian airline which was operating the aircraft involved in the investigated Serious Incident was the means through which the Swedish Company Avies Sverige AB fulfilled its contract to provide domestic air services on specified routes in Sweden in accordance with a contract with the Swedish Transport Administration, which it had been awarded after a public tender process.

It was found that relevant recorded data from the 30 minute CVR had been overwritten because the power supply CB to it was not tripped after the excursion. The FDR did contain relevant data but its use was hindered by the inability of the operator to provide the engineering units conversion which is specific to each individual aircraft. Instead, it was necessary to provide generic conversion documentation provided by the UK AAIB. Some civil and military air traffic radar data was also available.

The 56 year old aircraft commander had 14,560 hours flying experience which included 620 hours on the aircraft type involved. The 22 year old First Officer had 620 hours total flying experience which included 450 hours on the aircraft type involved.

It was established that the aircraft had operated the flight at a total mass which was essentially the same as the maximum permitted. The minimum required fuel had been loaded in order to accommodate all the passengers and two alternates had been nominated accordingly. The flight had proceeded en route from Stockholm in IMC through an area of widespread snowfall and icing conditions, the latter severe in places and the subject of six SIGMETs during the day. There were 15 passengers on board but no cabin crew. The First Officer was PF. The weather report from Torsby twenty minutes before the excursion occurred gave the wind almost calm, the visibility 2000 metres in snow, a vertical visibility of 1900 feet and the air temperature and dew point MS05 and MS06 respectively. The most recent runway friction measurements taken by use of a SAAB friction tester at the same time as the weather report were 0.30, 0.31 and 0.33. Following this measurement, snow clearance continued until approximately 7 minutes prior to the landing.

It was unclear to what extent any meaningful checks had been made for airframe icing en route or before commencing the approach. The First Officer "could not remember" and without an AP fitted would have had to rely on the PM to undertake such checks. The commander stated that he "considered the (J32) aircraft to be designed to cope with a lot of ice and only had good experiences of flight under severe icing conditions".

A procedural approach was flown routing outbound to the NDB 'TH' followed by a procedure turn onto a LOC/DME final approach to runway 16. A 35 flap landing was made and the calculated Vref was 115 KIAS. A PAPI was available. Based on recorded flight data and interviews with both pilots, the Investigation concluded that the final part of the approach had been unstabilised. The data showed that both airspeed and glide path angle had "varied to a significant degree" as the aircraft neared the runway, and both pilots recollected that it had been necessary to correct both altitude and glide path angle when PAPI became visible indicating that the aircraft was too low. It was noted that "given that an altitude which is too low is perceived as a more hazardous position than the opposite, it is easy for an altitude adjustment to result in an overcorrection that leads to a reverse situation in which the aircraft will be too high". This occurred and at a late stage in the approach, the aircraft was both too high and too fast with "the scope for further correction of these parameters probably insufficient". It was considered that "(more) effective crew cooperation supported by a coherent concept for stabilised approach would have led to the approach being abandoned and a go around commenced".

It was found that although the Operator used the expression “stabilised approach” in its manuals, there was no guidance which would allow this concept to be applied in practice. It was also noted that "the manuals also lack instructions for when an approach is to be abandoned".

It was established that touch down had occurred about half way along the 1590 metre runway 16 with excessive speed. The First Officer had retarded the throttles to idle and initiated thrust reversal whilst handing over control of the aircraft to the commander. Having taken over, the commander began braking and selected maximum reverse propeller pitch. However, it was not possible to stop the aircraft or reduce its speed sufficiently to allow it to exit the runway under normal directional control at the usual place near the end of the runway. An attempt to make this 90° right turn onto taxiway 'A' resulted in loss of directional control and the aircraft exited the right hand side of the runway at an approximate 45°angle before almost immediately entering snow which was up to 40 cm deep. This rapidly slowed its progress and it finally stopped with the nose 6/7 metres beyond the taxiway edge in the position shown on the diagram below.

The landing runway with relevant annotations. Reproduced from the Official Report.
The final stopping position of the aircraft. Reproduced from the Official Report.

It was found that the Operator had no procedures for correcting runway performance calculations for contaminated surfaces. It was also found that although there had been no recording of any technical defects in the Aircraft Technical Log, a number of such defects were known to both the flight crew and the Operator's Technical Department. These included inoperative right hand propeller de icing, defective right hand side cabin lighting and missing pitot covers. In respect of the first of those, the Investigation was of the opinion that "the fact that the commander made the decision to carry out the flight with the right propeller's de-icing system unserviceable in a weather situation where severe icing was expected may be considered remarkable".

The Investigation noted that a previous investigation involving a 2013 double engine malfunction on another Jetstream 32 of the same operator had discovered a similar situation with regard to defect recording and had concluded as follows:

  • Technical remarks are not normally noted in the aircraft's logbook; they are instead transferred to a document named “Maintenance request”. This document is sent in an appropriate manner to the operator's maintenance organisation for a decision concerning appropriate measures.
  • The pilots are instructed not to write any technical remarks before the defect/problem which has arisen has been confirmed by a certified technician. The routes that the operator's aircraft fly in the Swedish line network entail that the aircraft meet a technician once per week on average.
  • The operator has stated that the system works well in general and that there have only been a few instances of misunderstandings. The reason for the pilots being instructed not to write the technical remarks in the logbook is, according to the operator, that this entails a greater risk that the aircraft will be grounded.

Overall, it was considered that the various deviations from what might be regarded as normally expected operating practices which the Investigation had identified "probably do not have their primary basis in deficiencies of the crew, but can be viewed as a measure of how well the operator is doing in its systematic safety work". It was considered that "commitment, management and communication with the intent to create systematic safety work at a high level must come from the operator's management" and that the problems found with the style of operation were "of both of a kind and an extent that are hardly consistent with the requirements that must be placed on a commercial operator".

It was therefore concluded that "it must also be questioned why these recurring deviations with the operator have not been discovered by and (dealt with by) the Estonian aviation regulator 'Lennuamet', whose responsibility it is to approve and continuously exercise supervision over the activities of the Operator in question."

The Investigation formally described the Causes of the accident by providing a linked sequence from the outcome back to the systemic lack of effective regulatory oversight as follows:

  • The crew was unable to get the aircraft to stop after landing and it veered off the runway.
  • The touchdown took place too far along runway and at too high speed.
  • The approach was not stabilised.
  • The operator did not apply any coherent concept for stabilized approach.
  • The operator's weighing of production against safety has not been in balance.
  • The operator's systematic safety work has not lived up to the requirements that must be imposed on a commercial operator.
  • The responsible regulator has failed to detect and take measures against the deficiencies in the operator's systematic safety work.

The Investigation decided that as the Swedish Transport Administration had terminated its contract with the Aircraft Operator involved with effect from 6 March 2015, it was appropriate to limit any Safety Recommendations to the Estonian civil aviation regulator, 'Lennuamet'

Accordingly, one Safety Recommendation was made as follows:

  • that Lennuamet should tighten its supervision of the operator, AS Avies, in order to ensure that operations are conducted in accordance with applicable flight safety requirements, in particular with respect to such deficiencies as identified in section 2.5 of the Investigation Report. [RL 2015:10 R1]

The Final Report was published on 22 June 2015.


Further Reading