Southwest Airlines 737-300. By Rob Finlayson

Southwest Airlines' (SWA) smooth path to integrating with AirTran Airways, which it acquired last year, hit some turbulence with Tuesday's rejection by the carrier's 1,600 mechanics of a seniority integration agreement.

The Aircraft Mechanics Fraternal Assn. (AMFA) Local 11 had reached an accord with SWA and AirTran's 400 mechanics, but the members have voted to reject it, taking a different track from flight attendants and pilots who have approved integration pacts (ATW Daily News, Nov. 9, 2011).

"Our goal continues to be the speedy resolution of seniority integration," SWA VP-maintenance operations Jim Sokol said in a statement. The airline said "the next step" is filing for arbitration, but added that it "remains open" to working toward a negotiated solution.

SWA and AirTran expect to receive a single operating certificate from FAA next month.