American Airlines says it is wrapping up reviews of two incidents in December where wingtips of Boeing MD-80 aircraft touched the ground during landing.
The incidents occurred at Charlotte Douglas International airport and Austin-Bergstrom International airport.
Those two incidents and the 23 December overrun of an American Boeing 737 at the Norman Manley International airport in Kingston, Jamaica have prompted the US FAA to increase inspector oversight of American to determine if those three events are indicative of a larger issue, says the agency.
American says it does not believe the two wingtip events are related.
The carrier also says it is cooperating with FAA and other authorities in the investigations of all three incidents.
FAA also conducted a separate investigation in 2009 of American after the carrier disclosed a discrepancy in fasteners that were used to repair bulkheads on a small number of its MD-80 aircraft. At the time American said the fasteners were of aerospace quality, and explained it removed the aircraft featuring those fasteners from revenue service to complete inspections and appropriate maintenance actions.