American Airlines said that by Friday it had repaired seat locks on 40 Boeing 757 jets after some seats came loose during flights.
American said all 48 of its 757 jets that were to get the seat adjustments would be back in service by Saturday.
The carrier had cancelled 94 flights over Thursday and Friday to improve the locking mechanisms used to secure seats to aircraft floors.
"We have identified the issue and our maintenance teams are securing an FAA-approved locking mechanism to make sure no seat can be dislodged," an American spokeswoman said in a statement.
In recent days, there were three separate incidents in which seats on American Airlines flights came loose from the floor, prompting an investigation by the FAA and jet inspections. American said an internal probe showed that improperly installed clamps had caused seats to loosen in six aircraft.
American Airlines has just over 100 757s, but only 48 use the seat model that has caused problems.