GATINEAU, QC, June 20, 2013 /CNW/ - An aircraft identification mix-up,
combined with a loss of situational awareness likely brought on by
fatigue, are the central contributing factors in a loss-of-separation
occurrence between 3 aircraft (2 departing and 1 landing), a
Transportation Safety Board of Canada (TSB) investigation (A11P0073)
has concluded. Aircraft are required to maintain a minimum distance
from each other to reduce the risk of collision and a possible
encounter with aircraft-generated turbulence.
On 15 April 2011 at the Vancouver International Airport, a Jazz Airlines
de Havilland DHC-8 took off from the mid-point of Runway 26L at the
intersection of taxiway E, while a Westjet Boeing 737 was waiting to
take off from the threshold of the same runway. An identification
mix-up resulted in a delay in getting the departing aircraft airborne
in time to allow for the landing of an arriving Westjet Boeing 737.
Realizing that a conflict between the 2 Boeing 737s was developing, the
air traffic controller directed the arriving 737 to carry out a
go-around. The 2 Boeing 737s lost their required separation when they
came within approximately 2000 feet lateral spacing, with the departing
aircraft climbing through the altitude of the aircraft carrying out the
go-around. The minimum required separation is 30 degrees on a divergent
course until the aircraft have achieved at least 1000 feet vertical
spacing, and this separation was not restored in a timely manner.
In this investigation, the TSB found that the air traffic controller's
loss of situational awareness resulted in an operational decision that
led to a loss of separation between the two 737s. The investigation
also found that it is likely that the air traffic controller was
suffering the effects of fatigue at the time of the occurrence. That
would have made it more difficult for the controller to recognize the
developing situation and to take timely corrective action to ensure
that separation was maintained.
NAV CANADA has taken additional measures to enhance safety at the
Vancouver International Airport. It has prohibited departures of
aircraft from a runway at a point other than the threshold. NAV CANADA
is also looking to improve its existing Fatigue Management Program with
a goal of better managing controller fatigue in a 24-hours-per-day,
The TSB is an independent agency that investigates marine, pipeline,
railway and aviation transportation occurrences. Its sole aim is the
advancement of transportation safety. It is not the function of the
Board to assign fault or determine civil or criminal liability.
SOURCE: Transportation Safety Board of Canada
For further information:
Transportation Safety Board of Canada
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