Aircraft Model Has History of Landing-Gear Problems

The Canadian-built airplane that crashed into a suburb of Buffalo, N.Y., Thursday night was a Bombardier Q400, a commonly used model of medium-range passenger aircraft — but one with a troubling history of landing-gear problems.

Scandinavian Airlines pulled all 27 of its Q400s out of service permanently in the fall of 2007 after three of the planes experienced landing-gear failure within six weeks. Five people were injured when one of those planes crash-landed.

There is no indication that landing-gear problems played a role in the crash of Flight 3407 Thursday night. A fatal crash of a similar Bombardier aircraft in New Zealand in 1995 was caused by pilot error resulting from distraction over stuck landing gear.

Following the first two SAS incidents in September 2007, Montreal-based Bombardier and the Canadian transport authority recommended that all Q400s worldwide — roughly 160 planes — be grounded for inspection.

But after the third incident — and a Lufthansa Q400 that had to make an emergency landing in Munich when its front landing gear refused to deploy — SAS grounded all its Q400s for good in October 2007.

"Confidence in the Q400 has diminished considerably and our customers are becoming increasingly doubtful about flying in this type of aircraft," the head of SAS said at the time.

• Click here to read SAS's press release detailing its decision to pull the Q400.

Bombardier ultimately reached a settlement with SAS and sold replacement short-haul aircraft to the airline at a discount.

Inspections of Q400 landing gears following the fall 2007 incidents found a remarkably rapid rate of corrosion in the landing-gear mechanisms, one that periodic inspections might not catch in time.

The inspection cycle for Q400s was sped up, and Bombardier management went through a personnel shakeup.

The Q400 model went into service in 2000, and Bombardier has sold about 300 at roughly $27 million each.

The plane is powered by twin Pratt and Whitney Canada PW150A turboprop engines, each of which spins a six-blade propeller. The Q400 has a top speed of about 410 mph, a top altitude of 27,000 feet, a maximum range of 1,500 miles, a wingspan of about 93 feet and a length of about 108 feet.

The Q400 is a variant of the very successful De Havilland Canada Dash 8, which first entered service in 1984, and a descendant of the smaller De Havilland Canada Twin Otter, first built in the mid-1960s and still in production. Military forces also use variants of the Dash 8.

"You'll find the Dash 8 at work in every part of the globe, from the Sahara to the Arctic and from the largest cities to the most remote airstrips," states the Bombardier Web site, which cites 23 commercial carriers worldwide as using the medium-capacity Q400.

Like the four-engine Dash 7, the two-engine Dash 8s are easily noticed for their "underslung" fuselage — the wings attach at the top of the body rather than at the bottom — and their high, T-shaped tails.

Bombardier acquired the De Havilland company in 1992 and redesigned the Dash 8 line to reduce noise, since many of its commercial customers operate the planes out of "city center" airports — hence the "Q" for "quiet" series.