The airplane forced into an emergency landing in Toronto after an engine shut down has had two previous documented cases of mechanical damage since it started flying five years ago, according to Transport Canada.
The Japan-bound Air Canada Flight 001 made an emergency landing Monday afternoon after experiencing an engine shutdown. That particular plane, a Boeing 777, had been involved in two other "incidents" involving mechanical failure since it was built in 2007, according to Transport Canada's Civil Aviation Daily Occurrence Reporting System (CADORS) database.
After landing at Charles De Gaulle airport in Paris on March 30, 2010, "smoke and flames were observed" coming out of the aircraft as it taxied to its gate. The problem was tracked to an auxiliary power unit, which provides power for some aircraft functions.
The crew switched it off, and safely taxied to the airport, eventually getting parts replaced, according to a CADORS report.
And on June 9, 2009, the plane struck a flock of geese as it approached the Vancouver International Airport on a flight from Hong Kong.
Pilots had spotted the flock and tried to avoid the geese, but struck approximately six of them, causing dents to the “fan nose cowl” and damage to four fan blades on its No. 2 engine. The plane was taken out of service for extensive repairs.
Air Canada spokesman Peter Fitzpatrick told CBC News on Tuesday that in-flight shutdowns are "extremely rare" for Boeing 777 aircraft, and there have not been any other such shutdowns in the last year.
There is regular day-to-day maintenance of the aircraft by Air Canada staff, Fitzpatrick said. The last major check of the aircraft — not including the engines — was done by a company called HAECO in Hong Kong "as per its regular schedule," said Fitzpatrick, without specifying exactly when.
Debris fell from engine
An investigation into what happened Monday has only just begun.
An official with the Transportation Safety Board confirmed Tuesday that debris from the Air Canada jet fell from the sky and damaged a number of cars near Pearson airport.
Don Enns, the regional manager of air investigations at the TSB, told CBC News that the debris from the aircraft came from the turbine section of the engine.
Peel Regional Police identified at least four vehicles that had been hit by pieces of metal about the size of a cellphone.
There were no reports of any injuries caused by the falling debris.
Enns said the TSB is still looking into why the engine failed. After TSB officials take a superficial look at it, the engine will be dismantled and examined more thoroughly.
"It's extremely rare that this kind of thing happens," Enns said.
"I cannot offhand remember an event where we had engine parts falling out of the back of the engine like this."
No apparent damage to front of engine
Enns didn't want to engage in "idle speculation" over the cause of the failure until a thorough examination has been conducted.
But he said a preliminary examination has shown that there isn't any damage to the front of the engine, where the fans are located.
"The failure appears to have happened in the turbine section," located at the back of the engine, said Enns.
Investigators have collected the flight data recorder and cockpit voice recorder, which may yield more clues about what happened, said Enns.
It could be a few weeks before investigators are able to remove the engine, disassemble it and examine it thoroughly, he said.
Before its flight to Tokyo's Narita International Airport, the aircraft flew in to Toronto from Frankfurt "without any snags or any problems whatsoever," he said.
Fitzpatrick told CBC News that the plane had an “engine shutdown” that occurred shortly after takeoff.
The crew then followed “standard procedures for dealing with the situation,” which saw them request an emergency landing.
The flight took off from Pearson at 2:10 p.m. ET and returned to make its emergency landing at 3:53 p.m.
The plane had 318 passengers and 16 crew aboard when it landed on Runway 23.
Jason Flick, a passenger aboard the flight, said he first knew something was wrong about 10 or 15 minutes into the ascent when the aircraft was still on an upward incline but wasn't gaining any altitude. The captain then addressed the passengers and said an engine had to be turned off due to overheating, and that fuel had to be dumped.
"I was concerned. I didn't think we were going to land the plane. If the engine is going, you can’t climb anymore. That’s not a good place to be," Flick told CBC News.
"I was certainly typing up some letters that may have been my last ones. I was certainly in that mode of thinking for a while."
Enns said the twin-engine airplane is designed to fly for up to two to three hours with just one engine.