The grounded aircraft had their seats checked, and at least four other aircraft had improperly secured seats, though none of the passenger seats on these aircraft came loose in flight. All aircraft were returned to service by October 7th.
The 48 grounded aircraft all had recent modifications to some rows of passenger seats where the rows of seats were moved to provide greater legroom. The airline identified several factors which led to the seat problems, including installation issues, problems with a seat locking mechanism, and the effects that spilled soft drinks and other debris may have had on the locking mechanism.
Other American Airlines issues
These seat incidents generated significant media attention last week, and caused the media and the flying public to scrutinize several recent American Airlines events that were unrelated to the 757 seat issues, including a flight delay due to problems with a pilot's seat, and unscheduled landings involving smoke in the cabin, a flap warning light, and landing gear issues.
Along with the recent incidents, American Airlines has been restructuring agreements with many of its unions after filing for bankruptcy last year. In the past couple of months, the company has announced announced that it will be closing down one majore maintenance facility and outsourcing some of its maintenance work that had previously been done by American Airlines employees.
No connection between seat issues and other events
While recent the recent 757 passenger issues and other safety-related incidents may be a cause for concern for some passengers, there is no obvious connection between those incidents and any changes in operational practices by American Airlines. It appears that only the loose passenger seat incidents were due to a related cause, and the airline took actions that addressed the problem.
As for the effect that going through bankruptcy and outsourcing maintenance may have on airline operations, no matter what organization performs the airline's maintenance, that organization will still have the same kind of regulatory oversight, and American Airline will still be responsible for ensuring that their aircraft meet or exceed all the appropriate requirements, regardless of their current financial condition.