WestJet flight to St. Maarten flew too low during landing approach: report

Significant changes in weather and visibility were factors in the 2017 close-call landing of a WestJet flight in St. Maarten, says a report released by the Transportation Safety Board of Canada on Monday.

Rain shower and reduced visibility distracted pilots on approach

A plane approaches for landing at the Caribbean island of St. Maarten. (Getty Images)

Significant changes in weather and visibility were factors in the 2017 close-call landing of a WestJet flight in St. Maarten, says a report released by the Transportation Safety Board of Canada on Monday.

The March 7 flight from Toronto was captured by photographers at Maho Beach, a popular spot for plane spotters and tourists located directly in front of the runway at Princess Juliana International Airport.

Video posted to YouTube shows the aircraft flying just 12 metres above the ocean before pilots initiated a missed approach manoeuvre.

The Boeing 737, carrying 158 passengers and six crew members, aborted the initial landing after being alerted to the danger by two cockpit alarms.

The report describes how on the day of the flight the weather and visibility were both initially good. During the aircraft's approach, however, moderate to heavy rain showers significantly reduced visibility to below the minimum amount required.

The visibility changes were not communicated to the crew and they continued with the approach.

At the same time, the airport's runway lights were turned on to an automatic night setting. While this slightly increased the brightness of the runway edge lights, it decreased the visibility of the precision approach path indicator lights.

Pilot misidentified runway

The report found the low-intensity settings of the lights limited the visual references available to the flight crew. The pilot misidentified the runway, mistakenly lining up the approach with a hotel to the left of the runway instead.

The increase in visual workload for the crew led to inadequate altitude monitoring, which reduced the crew's situational awareness, the report found. The crew did not notice that the aircraft had descended below the normal angle of descent.

Even when the aircraft exited the rain shower, about 1.6 km from the runway, the flight crew were not able to assess their height above the water and continued to descend while correcting their approach toward the runway.

The aircraft's enhanced ground proximity warning system then issued two alerts of "too low, terrain" at 19.5 metres and as the aircraft passed from 16.5 metres to 12 metres.

A Transportation Safety Board of Canada graphic shows the optimal approach to Princess Juliana International Airport in St Maarten versus the actual approach by WestJet Flight 2652 on March 7, 2017. (Transportation Safety Board of Canada)

Records indicate the aircraft dipped below 12 metres before ascending for the missed approach. The aircraft circled while the weather cleared and the plane landed safely about 45 minutes later.

At the time of the incident, WestJet downplayed its severity saying in a statement, "this 'near miss' was anything but." The airline added missed approaches are not uncommon.

The Transportation Safety Board report also noted WestJet originally assessed the occurrence as a "non-reportable event," meaning the cockpit voice recorder and digital flight data recorder data were overwritten and not available for the investigation.

As a result of the incident, WestJet conducted its own investigation and changed its procedures for the airport. The airline also notified all pilots of the incident and possible challenges at the St. Maarten airport, including the misleading appearance of the hotel.