AAR’s facility in Duluth, Minn., opened its third line of maintenance in early September, which means the facility that the MRO opened last November is running at 75% capacity.

It has capacity for four lines, the last which should open in mid-2014, according to Chris Jessup, AAR’s senior vice president-airframe and engineering services, who spoke to Aviation Week on the sidelines of the MRO Europe Conference & Exhibition.

AAR, which launched operations at the former Northwest Airlines facility in November 2012 with one line, added a second in March. Jessup says starting the first line was easy, but adding each new line becomes a little more difficult because it becomes harder to recruit the technical maintenance personnel needed to support it.

AAR employs 275 people in Duluth, but would like to grow its workforce there by 40.

The company is performing heavy maintenance for Air Canada’s entire A320 fleet—about 89 aircraft—under a five-year agreement. The MRO signed a letter of intent with Air Canada in October 2012 after the airline’s previous airframe maintainer, Aveos in Canada, abruptly closed. Because the Duluth facility didn’t open until November, Jessup says AAR input Air Canada’s A320s initially at the MRO’s Miami facility, which still performs overflow work on the A320s.

AAR also services the majority of Air Canada’s A320 components through a separate contract.

In related news, Jessup says AAR is wrapping up two Airbus A330 lease-return jobs that it inherited after opening its new facility in Lake Charles, La., in August. AAR employs 150 people at that location.