B737, Fort Nelson BC Canada, 2012
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|On 9 January 2012, an Enerjet Boeing 737-700 overran the landing runway 03 at Fort Nelson by approximately 70 metres after the newly promoted Captain continued an unstabilised approach to a mis-managed late-touchdown landing. The subsequent Investigation attributed the accident to poor crew performance in the presence of a fatigued aircraft commander.|
|Actual or Potential
|Human Factors, Runway Excursion|
|Type of Flight||Public Transport (Passenger)|
|Origin||Fort St. John|
|Intended Destination||Fort Nelson Airport|
|Take off Commenced||Yes|
|Location - Airport|
|Airport||Fort Nelson Airport|
|Tag(s)||Approach not stabilised,|
Landing Flare Difficulty
Inappropriate crew response (automatics),
Plan Continuation Bias,
Procedural non compliance
|Tag(s)||Overrun on Landing,|
|Damage or injury||No|
|Causal Factor Group(s)|
On 9 January 2012, a Boeing 737-700 being operated by Enerjet on a passenger charter flight from Fort St. John to Fort Nelson overran the dry landing runway 03 at destination by 70 metres after an unstabilised visual approach had been flown in day Visual Meteorological Conditions (VMC). None of the 118 occupants were injured and there was no damage to the aircraft.
An Investigation was carried out by the TSB.
It was found that the Captain had approximately 7500 hours total flight time, 2000 hours on type and 50 hours as pilot-in-command and that the accident flight was his first following completion of line training. The First Officer was found to have had approximately 5600 hours total flight time with about 700 hours on type and had been free of duty for 38 days prior to the day of the accident.
It was established that the aircraft commander, acting as PF had briefed for a visual approach to Fort Nelson ‘backed up by the ILS’. Descent had been continued below the altitude appropriate to the intended and achieved 5nm range from touchdown turn onto final approach which had occurred at 2200 feet Altimeter Pressure Settings (equivalent to 950 feet aal). At this time, the AP was engaged, the flaps were at 15° and the landing gear was down. The AFDS had captured the localiser and the glideslope was armed. The PF had then selected VS on the MCP with a descent rate of -500 fpm despite the fact that the GS indication on the ADI was full scale ‘Fly Up’. The EGPWS Mode 5 ‘Glideslope’ Alert activated twice and the PF stated that he was correcting. Shortly afterwards he disconnected the AP and the GS was finally intercepted 40 seconds before touchdown at 420 feet aal. However, the aircraft was then allowed go above it before the PF made a corrective pitch down which produced an increase in rate of descent to almost 1000 fpm and a speed of 142 KIAS against the applicable Reference Speed (Vref) of 128 KIAS.
The A/T was not manually disconnected prior to beginning the landing flare and approaching touchdown it did not automatically enter retard mode passing 27 feet agl because the MCP setup selected was the one corresponding to a go around - SPD mode with the AFDS set up for ALT ACQ. The aircraft touched down 6knots fast at 134 KIAS, some 550 metres from the threshold with 1400 metres of runway remaining. When the PF moved his hand to actuate the thrust reversers, the A/T advanced the thrust levers in order to maintain the MCP-selected speed of 133 knots. The extension of the speed brakes was also prevented by thrust rising above idle. The PF captain repositioned his hand on the thrust levers, disconnected the A/T and selected Flight Idle. Contrary to SOPs the First Officer did not call out "no speedbrake", "no reverse", or "autobrake disarm" during the initial roll-out. Deceleration began about 5 seconds after touchdown with approximately 760 metres of runway remaining with full manual braking and reverse thrust and speed brakes deployed. The rate of deceleration averaged thereafter - MS 0.35 g - was consistent with a bare and dry runway surface. It was noted that although the length of the landing runway “was appropriate to the operation (it) afforded little room for deviation from aircraft speed on landing and the touchdown point”. Having failed to stop on the paved runway surface, the aircraft exited the end at 10 to 15 knots before coming to a stop 70 metres further on and approximately 6 metres to the left of the extended runway centre line with the main landing gear on frozen soil and the nose landing gear in approximately 50 cm of snow.
It was considered that a number of aspects of the way the approach had been flown were “consistent with a combination of attention decrements” which could be associated with the Captain’s statement that he had “not attained any appreciable sleep in the 24 hours preceding the flight”. The Investigation considered on the basis of the way the approach had been flown that the Captain had been fatigued and that the condition “may have adversely affected his judgment and ability to adequately evaluate and manage operational risks”. It was noted that at the time of the investigated event, Enerjet did not have an FRMS in place nor was one required by regulation. It was noted that the Captain had decided to report to work that morning although he had not achieved any appreciable sleep the night before. Although aware of an “alertness assessment tool” contained in the Company Operations Manual, he made no use of it and had not received any training from Enerjet in respect of fatigue and fatigue countermeasures.
In respect of the potential consequences and available response to any aircraft overrun accident at Fort Nelson it was noted by the Investigation that:
- Although the recommended Runway End Safety Area was not designated for the overrun which occurred, “the terrain up to 150 metres beyond the runway end is free of obstacles and is graded such that rescue vehicles can manoeuvre effectively around an aircraft in that area”.
- Aircraft rescue and fire-fighting (Rescue and Fire Fighting Services) services were not available at the airport nor were they required to be since an airport has to handle more than 180 000 passengers for this to be a requirement and in 2011, Fort Nelson handled only 34206 passengers in the course of 22050 aircraft movements.
- Emergency response for the airport is the responsibility of the Fort Nelson Fire and Rescue which is located in the town of Fort Nelson from which response time is estimated as 7 minutes.
The formal Statement of the Findings of the Investigation as to Causes and Contributing Factors was that:
- The Captain did not attain appreciable sleep in the 24 hours preceding the flight and was fatigued, likely resulting in attention decrements.
- The Captain continued the approach when the aircraft was not in a stabilized configuration, consistent with fatigue-induced reduction in forward planning and a focus of attention towards salvaging the flight.
- On short final the Captain pitched the aircraft nose down in an attempt to capture the glideslope which was (by then) below their flight path. The nose down attitude increased the airspeed resulting in a longer flare and a touchdown beyond the recommended 1000 feet mark, thus reducing the amount of available runway for stopping.
- The autothrottle system was not disengaged below 50 feet, which resulted in the A/T system increasing thrust in order to maintain the selected airspeed. This increase in thrust delayed the deployment of the speed brakes and thrust reversers, which left insufficient runway in which to stop.
In respect of Risk, the Investigation concluded that:
- If flight crews are not given training on fatigue and fatigue countermeasures, they risk not having the tools they need to deal with fatigue.
- If flight crews are required to assess their own level of fatigue and the effects it will have on their performance, they may not identify unacceptable levels of fatigue.
It was also formally noted as an additional ‘Other Finding’ that “the conditions experienced on landing were equal to or better than the runway surface condition report and Canadian Runway Friction Index readings indicated”.
Safety Action taken by the aircraft operator Enerjet as a result of the event was noted as the May 2012 issue of a communication to all flight crew that contained an open-book exam on relevant sections of the Company Operations Manual. The exam submissions were corrected to 100% at an all-pilots meeting the following month. It was noted that “the goals of this activity were to raise awareness of the fatigue self-assessment tool in the Operations Manual and to provide an opportunity for reiterating the importance of making fair and honest assessments of fitness for duty and reassuring pilots that booking off duty was non-punitive in cases such as fatigue/illness/stress".
In the context of having undertaken another runway overrun investigation, the Investigation also noted that the safety issue posed by landing accidents and runway overruns had been included in recent issues of the TSB “Watchlist” and that the Board has investigated a number of landing accidents and incidents of this type and identified deficiencies, made findings, and issued safety communications on subjects such as runway surface condition reporting requirements and on the provision of RESAs. It noted that benign consequences of the overrun investigated in this case still served to particularly highlight the latter issue and that the event “brings attention to the necessity for airports to provide adequate safety areas at the end of runways or other engineered systems and structures to safely stop planes that overrun.”
The Final Report of the Investigation was officially released on 25 April 2013. No Safety Recommendations were issued.
- Runway Excursion
- Stabilised Approach
- Fatigue Risk Management System (FRMS)
- Beyond the Runway End Safety Area
- European Action Plan for the Prevention of Runway Excursions (EAPPRE) Edition 1.0, January 2013.
- Decision-Making Training (OGHFA BN)
- Situational Awareness
- Continuation Bias
- Runway Overrun After Unstabilised Approach (OGHFA SE)