OTTAWA—A WestJet flight nearly collided with the water during an approach to a Caribbean airport after the pilots lost sight of the runway in a rain shower and it took a cockpit alarm to warn them about the impending danger, a new report reveals.
The Boeing 737 was just 12 metres (or 40 feet) above the ocean when pilots aborted their approach after the jet’s ground proximity warning system twice sounded, “too low, terrain,” according to an investigation into the Mar. 7, 2017 incident by the Transportation Safety Board of Canada.
In a report released Monday, the board concluded there was a risk of collision with the water and that the pilots failed to notice that the aircraft, WestJet flight 2652 from Toronto’s Pearson International Airport to Sint Maarten, had descended too low, until the warning system issued the alert.
“The sudden and unexpected poor visibility during the final approach increased the flight crew’s visual workload and led to inadequate altitude monitoring,” the safety board said in a statement that accompanied the report.
The airport at Sint Maarten is nestled between island hills and the ocean and the landing approach is made from the west over the ocean. It’s well-known for the beach at the end of the runway and nearby bar where plane spotters gather to watch the arrivals and departures.
One of those spotters took video of the dramatically low approach. In another video posted on YouTube, a passenger onboard comments, “oh my God, we are so low” as the jet descends to the water.
The weather was initially clear, but, as the WestJet flight neared the island, moderate to heavy rain showers began moving through the area. These reduced visibility dramatically. In the poor conditions, the crew initially lined up on a beachside hotel, which they mistook for the runway.
“The features of a hotel located to the left of the runway, such as its colour, shape, and location, made it more conspicuous than the runway environment and led the crew to misidentify it as the runway,” the report said.
“The reduced visibility and conspicuity of the runway environment diminished the crew’s ability to detect that they had misidentified the runway,” the report said.
Safety investigators identified other factors, too; the air traffic controller failed to tell the pilots about the worsening visibility. “Significant changes in visibility were not communicated to the crew, which allowed them to continue the approach when the visibility was below the minimum required to do so,” the report said.
As well, despite the decreased visibility, the runway lights were only set at low, which impeded the ability of the pilots to identify the runway.
The jet exited a rain shower about 1.6 kms from the runway and about 57 metres above the water.
With the improved visibility, the pilots saw they had deviated left of the approach course but were not able to assess their height above the water.
The sharp drop-off in visibility caused the pilots to focus their attention outside the cockpit and they failed to properly monitor the plane’s altitude, the report found.
“The lack of visual texture and other visual cues available over water contributed to the crew’s inability to detect the aircraft’s reduced height above the water,” the report said.
The automated terrain warning was unexpected and it took the crew time to comprehend the peril.
“It took them several seconds to understand that they were indeed too low,” the report said.
After the aborted approach, the pilots delayed their next landing attempt until the weather had improved, arriving safely at the airport 45 minutes later.
WestJet initially downplayed the incident and criticized what it called “irresponsible headlines” that there had been a close call. In a statement, the airline said that “this ‘near miss’ was anything but.”
But, in the wake of the incident, the airline amended its procedures for the airport and cautioned pilots flying there to use extra diligence during times of low visibility. It also alerted flight crews to the misleading appearance of the nearby hotel.
Source : TheStar