Transport Canada has ordered Bombardier CRJ700, CRJ900 and CRJ1000 operators to modify slat components to prevent failure of a pin that could cause the related slat to break away.

The directive (CF-2013-31), which is effective Oct. 22, gives operators 6,000 flight hours or 30 months, whichever comes first, to replace locking plates with “an anti-migration assembly” on both the left-and right-wing No. 3 slats.

“It was discovered that for certain slat system jam-disconnect failure cases, the resulting slat skew could lead to failure of the eccentric pin at the slat track 3-3 attachment,” says Transport Canada. “If the pin migrates out of the attachment lugs, this could cause the No. 3 slat panels to disconnect from the wing.”

The directive is based on a Bombardier service information sent to operators in June.

The order applies to all CRJ700s, CRJ900s and CRJ1000s. Aviation Week’s Commercial Fleets database shows 637 such aircraft in service or storage, including 340 CRJ700s and 262 CRJ900s.