American Airlines says that an improperly installed saddle clamp resulted in a row of seats coming loose in-flight on two of its Boeing 757-200s.
The Fort Worth-based Oneworld carrier says that the clamp in question is used to secure seats to the aircraft floor on 47 of its 757s. It has expanded seat inspections to all of these aircraft from the initial 10.
"American planned to evaluate the seats on eight Boeing 757 airplanes, but out of an abundance of caution, the decision was made to proactively evaluate a total of 47 Boeing 757 airplanes that have the same model main cabin seats with a common locking mechanism," says American.
The airline says that 36 757s were inspected by the end of 2 October, with the remaining 11 aircraft to be inspected overnight and today.
The investigations follow a row of seats becoming loose on multiple occasions on two Boeing 757-200s. The first incident occurred in row 14 seats A, B and C during flight on American 2206 from Vail to Dallas-Fort Worth on 26 September, the same row then came loose after a flight from Dallas to Boston on the same day, and it came loose a third time during flight 443 from New York's John F. Kennedy (JFK) to Miami after which the aircraft returned to JFK on 1 October.
The problem was first identified on the 757 in row 12 seats D, E and F on the ground in Miami on 27 September after which the clamps were tightened. The row came loose again in the air on flight 685 from Boston to Miami and the aircraft was diverted to JFK on 29 September.
American and the US Federal Aviation Administration (FAA) are working closely regarding the seat clamp investigation, the airline says.
The FAA said that preliminary information indicated that the seats on two of the diverted flights were recently removed and re-installed, in a statement on 2 October.
The Transport Workers Union said that maintenance contractor TIMCO conducted the majority of the seat installation, in a statement on 2 October. "Problems related to seats are less likely a labour problem, but rather a management issue related to outsourcing work to third-party facilities," it says.
TIMCO says that they are working closely with American on the issue and declines further comment.
"The issue does not seem to be tied to any one maintenance facility or one workgroup," says American. "Safety is - and always will be - American's top concern."