Southwest and FAA have come up with an agreement that addresses a batch of unapproved parts flying on planes but does not call for groundings, so long as the bad parts are swapped out by Dec. 24. Check out our own Andy Compart's story for a summary of what both sides said publicly about the deal, or read it yourself in the official statements from FAA and Southwest.
Flying a bit more under the radar is Southwest's petition for exemption on the matter. In it, the carrier explains how unapproved flap gate exhaust assembly brackets got onto 82 of its aircraft, and how it reacted.
Put simply, D-Velco--which was at the time on Southwest's Approved Vendor List--subcontracted the machining of "certain brackets" to a company called Future Fab Precision Machining. But D-Velco's Repair Station Approved Maintenance Functions List did not include "machining," which means D-Velco was not allowed to contract the work out (see FAR Part 145.217). FAA's Certificate Management Office overseeing Southwest discovered the problem and notified the airline on August 21.
The carrier "immediately" suspended D-Velco from its approved-vedor list and went to work analyzing the problem. Southwest's engineering department analyzed 10 brackets and found that eight of them conformed to Boeing's production specs. Two brackets "had minor dimensional deviations from the Boeing production specifications and some were constructed of a slightly different aluminum alloy," the carrier explained in the petition. Southwest conferred with Boeing, and the OEM said the brackets are "structurally acceptable."
Meanwhile, Southwest mechanics inspected the affected in-service planes and found "no abnormal conditions," the carrier said. The carrier then began to work on its plan to get the unapproved parts out of service.
Here's a direct link to Southwest's petition (.doc).