The Boeing 747 cargo jet that overshot a runway at Halifax’s international airport on Wednesday had touched down in rainy conditions while being buffeted by a crosswind with a potential tailwind, the Transportation Safety Board of Canada said Thursday.
The four crew members suffered minor injuries when the empty SkyLease Cargo plane slid 210 metres off the end of Runway 14 at Halifax Stanfield International Airport, which means the big jet was headed in a southeasterly direction.
“I believe it was the pilot’s request for that runway, but that’s preliminary,” lead investigator Austin Adams told a media briefing at a hotel near the airport.
He said weather data recorded seven minutes before the aircraft landed showed the wind was gusting at 33 kilometres per hour from the west at 250 degrees.
He said the “strong westerly winds” created a crosswind for the aircraft, which included the potential for a “quarterly tailwind.”
Aviation analyst and former safety board investigator Larry Vance has said it appears the plane landed with a tailwind – something he called an “immediate red flag.”
Vance said airplanes typically take off and land into the wind, which offers pilots more lift and, as a result, more control.
However, all aircraft are designed to land with a crosswind or tailwind, though each aircraft has its limits, said TSB investigator Isabelle Langevin. She said the board will be looking into the limits for the Boeing 747-400.
When asked why a pilot would chose to land on a wet runway while dealing with a tailwind, Adams said it all comes down to what was decided in the cockpit.
“I don’t want to speculate or state anything,” he said. “I want to engage the crew and speak with them about their decision-making process.”
Flight KKE 4854, which had arrived from Chicago just after 5 a.m., was to be loaded with live lobster destined for China.
As the plane slid down a slight embankment covered in grass, it hit a large localizer antenna, its landing gear collapsed, two of its four engines were torn off and there was a small fire under the tail section – caused by one of the severed engines.
The safety board, which is an independent agency, says there has been an average of nine overrun incidents every year in Canada since 2013.
“The consequences can be particularly serious when there is no adequate runway end safety area or suitable arresting material,” the board said in a statement.
In the days ahead, Adams said his team will interview the crew and download and analyze the data from the aircraft’s cockpit voice recorder and flight data recorder. They also plan to talk to witnesses, air traffic controllers and airport personnel.
As well, the investigation will review radar data, weather conditions, aircraft systems, maintenance records, pilot training and operational procedures.
If the investigation uncovers any safety deficiencies that present an immediate risk, that information will be immediately relayed to the public and safety officials.