American Airlines says it is installing back-up locking devices on seat tracks of 49 Boeing 767-300s.
The installation of the secondary locking devices on the majority of American's fleet of 58 767-300s will require nine days to complete, but will not result in flight cancellations, the airline says.
The Oneworld carrier decided to install the back-up device because the 49 767-300s use the same primary locking mechanism that failed on at least two 757-200s in September.
American already has rolled out back-up locks on the seat tracks for the 757 fleet.
The rest of American's fleet use a different primary locking system, and do not require a back-up, the carrier says.