Tire problem factor in plane's belly landing

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City firefighters at the scene of the Perimeter Aviation plane’s belly landing at Richardson International Airport March 3. (MIKE DEAL / WINNIPEG FREE PRESS ARCHIVES)

PUT a tire that's too wide on your car, and you'll find it won't stay on the rim -- but if you try the same thing with an airplane's wheel, you might have to make a pancake landing on a runway.

That's part of what federal aviation crash experts have determined happened to a Perimeter Aviation plane earlier this year when its landing gear failed to come down and the two pilots were forced to make a belly landing at Winnipeg's Richardson International Airport on March 3.

The two crew and eight passengers on board, en route from St. Theresa Point to Winnipeg, walked off the plane with no injuries, but were taken to hospital as a precaution.

Peter Hildebrand, regional manager of the Transportation Safety Board of Canada, said on Friday the twin-engine Metro II plane's right landing gear door didn't open all the way because the tire was about a centimetre too wide, causing it to hook up on the gear door's raised ledge.

Hildebrand said not only was there a problem with the ledge, but the gear door was also installed incorrectly.

"The landing-gear doors aren't like your car's door, which is installed at a factory and goes years without change," Hildebrand said.

"Landing doors are subject to vibration (and) high speed and they're out in the cold and heat. They have stress and they're always in a state of flux.

"And then you put on a newly recapped tire. It (the doors) would work with the original tire, but when you put one on a bit larger, it changes things."

Hildebrand said it all culminated in the pilots not being able to put down their right landing gear.

Hildebrand said the plane was manufactured in 1976 by the Fairchild Aircraft Corp. He said the landing gear door on later Metro IIs were designed without the ledge, which on the earlier models were there to give the door more strength.

And Hildebrand said in the wake of the pancake landing, the manufacturer reissued its 1984 notice on tire-size information for airlines flying the aircraft.

Mark Wehrle, Perimeter's general manager, said they've already designed a new device to ensure the tire's width is the right size before it is put on a plane.

But, Wehrle said "tires tend to grow from the heat and the centrifugal force.

"And it's a tight fit there. The original aircraft had much smaller tires, but then they put in larger tires... and the manufacturer's specifications change over the years."

Wehrle said the company is also looking at redesigning the landing gear doors.

Wehrle said the plane was damaged on its belly, flaps and propellers, but it has been repaired and put back into service.

"The damage was very minimal," he said, noting it cost less than $30,000 to fix.

"Our pilots did a great job of setting it down fairly gently."

kevin.rollason@freepress.mb.ca

Republished from the Winnipeg Free Press print edition November 7, 2009 A3