Unstable approach and loss of visual reference led to February 2015 impact with terrain at the Sault Ste. Marie Airport, Ontario Français
RICHMOND HILL, ON, March 9, 2017 /CNW/ - In its investigation report (A15O0015) released today, the Transportation Safety Board of Canada (TSB) determined that the continuation of an unstable approach following a loss of visual reference led to a Jazz Aviation LP aircraft contacting the surface short of the runway at the Sault Ste. Marie Airport, Ontario, in February 2015. There were no injuries, but there was significant damage to the aircraft.
On 24 February 2015, a de Havilland DHC-8-102, operating as Jazz Aviation LP flight JZA7795 and carrying 15 passengers, departed Toronto/Lester B. Pearson International Airport, Ontario, for a scheduled flight to Sault Ste. Marie Airport, Ontario. While on approach to Runway 30, in conditions of twilight and reduced visibility due to blowing snow, the aircraft touched down approximately 450 feet prior to the runway threshold. Following touchdown, the aircraft struck and damaged a runway approach light before coming to a stop approximately 1500 feet past the threshold.
The investigation determined that a significant power reduction and subsequent decrease in airspeed, while flying below the minimum stabilization height of 500 feet, resulted in an unstable approach. This rapid deceleration steepened the aircraft's vertical path. The crew had reduced power in order to reach the target airspeed for the final approach and landing.
The crew had followed what they understood to be the correct speeds for the approach according to the company's guidance material. Due to ambiguity in the guidance and uncertainty as to the required speed during the approach, the flight crew did not recognize that the approach was unstable and continued the approach to a landing.
The investigation also found that the rapidly changing weather decreased the flight crew's visibility of the runway, and that the steepened vertical profile created as a result of the power reduction went unnoticed, and uncorrected. Although the loss of visual reference required a go-around, the flight crew continued the approach.
An examination of over 500 similar flights on Jazz DHC-8-102s showed that company aircraft routinely fly decelerating approaches below the minimum stabilization height of 500 feet. If approaches that require excessive deceleration below established stabilization heights are routinely flown, then there is a continued risk of an approach or landing accident.
Unstable approaches are one of the key safety issues on the 2016 TSB Watchlist. There is also an outstanding Board recommendation (A14-01) calling for Transport Canada to require commercial air services to monitor and reduce unstable approaches that continue to a landing.
Following the occurrence, Jazz Aviation LP undertook a number of safety actions such as making amendments to the Jazz DASH 8 Aircraft Operating Manual, by introducing significant changes to the "Stabilized Approach Factors" subsection and adding simulator scenarios to the training syllabus.
See the investigation page for more information.
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SOURCE Transportation Safety Board of Canada
Transportation Safety Board of Canada, Media Relations, 819-994-8053, [email protected]
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