Two days after American Airlines said it had inspected and discovered what caused rows of seats on three different passenger jets to come loose in flight and returned those planes to service, the troubled carrier is taking planes out of service for repairs once more.
American Airlines will make repairs to 48 757s at their next stops, the airline said in a written statement.
"American has instructed mechanics to pay particular attention to the seat lock plunger mechanism that secures the seat to the aircraft floor," American Airlines spokeswoman Andrea Huguely said in the statement. "Mechanics have begun taking steps necessary to ensure that no seat can become dislodged from its track. The work is expected to be completed after the 48 affected aircraft land at their next destination.
"Some select flights may be delayed or canceled in order to complete this work," the statement added. "We expect this work will be completed by Saturday, Oct 6. We apologize to our customers for any inconvenience this may cause with their travel plans. The safety of our customers and people as well as the reliability of our fleet, is always of utmost priority to American."
The decision to perform the maintenance was a voluntary decision by the airline. The Federal Aviation Administration endorsed the move and says its investigation is ongoing.
"The FAA is aware of American's decision to conduct further inspections on certain Boeing 757s and concurs with this step," the FAA's statement said. "Our safety investigation continues and we'll take additional action as appropriate."
It's been a difficult few weeks for the bankrupt carrier, whose parent company filed for bankruptcy protection last year.
Almost 50 of American Airlines' fleet of Boeing 757s -- nearly half the fleet -- were taken out of service earlier this week after three incidents of seats becoming loose in flight.
In one case, passengers flipped on to their backs.
The airline said Tuesday the seats' saddle clamps were improperly installed on the planes where the seat rows disengaged. Many of those planes were put back in service.
The first reported instance of seats becoming loose took place on Sept. 29 when seats came unbolted on flight 685 from Boston to Miami. The flight was diverted and made an emergency landing at JFK.
A second incident took place on Monday. Flight 443 from JFK to Miami was returned to JFK without incident when the seats were discovered, the Federal Aviation Administration said in a statement.
Then on Tuesday, it was reported that a Sept. 26 American Airlines flight from Vail, Colo., to Dallas had a similar seat issues.
The FAA said in a statement Tuesday it was looking into the first two incidents and that the airline's initial inspection of each aircraft had found other rows of seats that were not properly secured.
"Preliminary information indicates that both aircraft had recently undergone maintenance during which the seats had been removed and re-installed," according to the FAA.
The loose seats are just the latest in a series of troubles for American. The airline has suffered from heightened delays and cancellations in recent days.
"It's going to take American some time to rebuild trust in terms of the reliability of the schedule," Henry Harteveldt, airline and travel analyst at Atmosphere Research Group told ABC News.
AMR Corp., American Airlines' parent company, filed for Chapter 11 bankruptcy in November 2011.
The FAA has stepped up scrutiny of American during its bankruptcy, as it has in the past for other carriers in similar situations.
ABC News' Michael S. James contributed to this report.