TORONTO, ON — The alert system on a Delta Air Lines jet that flipped upside down and burst into flames as it tried to land in Toronto last month indicated a high rate of descent less than three seconds before touchdown, according to a preliminary report released on Thursday.
The Transportation Safety Board of Canada, which issued the report, continues to investigate the Feb. 17 crash-landing in which 21 people were hospitalized.
All 76 passengers and four crew members survived when the Delta plane arriving from Minneapolis burst into flames after flipping over and skidding on the tarmac.
“We’re not looking for fault, we’re looking for causes here, so we’re not looking for blame, we’re looking for what happened in these investigations,” said Paul Jackson, a former commercial airline captain.
Jackson said there may be multiple causes for a crash, which is why investigations are important.
“It looked like a very stable approach from until very, very late into the arrival and right before touchdown,” Jackson said.
The TSB of Canada report says that when the plane’s ground proximity warning system sounded 2.6 seconds before touchdown, the airspeed was 136 knots, or approximately 250 kph (155 mph). It says the plane’s landing gear folded into the retracted position during touchdown and the wing detached from the fuselage, releasing a cloud of jet fuel, which caught fire..
“Rate of descent was the issue,” said J. Joseph, owner and operator of Joseph Aviation Consulting.
Joseph is also an aviation accident investigator. The report doesn’t explain why part of the landing gear failed, but Joseph thinks the descent could be a factor.
“I would suggest that more likely that the problem with the landing gear was that it was simply overstressed by virtue of the fact of the rate of descent in which the aircraft touched down,” Joseph said.
“This is a long way from being concluded as to what caused this. If you had a gear failure on a component that should have been able to take this particular force or whatever term you want to use for that then we do have a cause, and it could be a mechanical cause,” Jackson said.
The safety board says its ongoing investigation is focusing on several key areas, including metallurgical examination of the wing structure, landing techniques, pilot training and the passenger evacuation process.
“Also you had some blowing snow and I think they’re going to look at that and they’re going to see that your depth perception can also get twisted a little bit visually,” Jackson said.
A man who was on the plane told KARE 11 the descent felt faster than normal. Jackson explained how the wind played a role.
“When you land an aircraft into a headwind you’re going to have a slower ground speed or your path across the ground. A passenger could look out and see that’s pretty normal, but with a crosswind you don’t have that. So they had a very, very strong crosswind and not a very large headwind component, so they probably were traveling across the ground faster and that could be a perception in the back of the aircraft,” Jackson said.
All of those who were hospitalized were released within days of the crash.
At least two lawsuits have been filed in the United States, and a law firm in Canada has said that it’s been retained by several passengers.