Remember that whole fiasco early last month when American Airlines had to ground nearly 50 of their 757s because the seats were tumbling around? In the best reporting on the subject so far, Christine Negroni got to the bottom of it in a New York Times piece and on her blog and disproves just about every excuse American threw out at the time.
No, it wasn’t caused by soda, nor was it a faulty clamp, as the airline claimed at different times during the media chaos that ensued.
Negroni has traced the problem back to failures at Timco, an aircraft services company that American hired to reconfigure their cabins with a few rows of premium economy seating. Similar work had previously been done by American employees without issue, but cost is king and Timco offered a better price.
Now we could write a book about why outsourced contractors can do work more cheaply than unionized airline employees, but one of the reasons is that Timco uses college interns to do some of their labor, especially boring jobs like seat installation. Note that unlicensed workers tinkering with airliners is completely legal so long as a licensed mechanic checks their work. Negroni reports, however, that the work was not done properly, and checks by both Timco and American employees did not discover the problems. (Her site also has some great scans of internal American service bulletins about the problem.)
Bottom line: While many businesses would have thrown their lowly interns under the proverbial (Air)bus in similar circumstances, I think it’s safe to guess that, legal or not, an airline doesn’t want to bring public attention to the fact that sometimes planes are fixed by less than experienced people.