American Airlines elected to cancel 1500 flights on Tuesday and Wednesday aboard its MD-80 aircraft as it conducted additional safety checks on the planes.

The decision by American Airlines to ground the MD-80s followed a recent FAA review of airline compliance with agency safety directives that expressed concerns over wiring inspections on the aircraft.

The carrier operates nearly 300 MD-80s, which represents about half of its entire fleet.  American Airlines uses the aircraft primarily on routes from its hub US city’s of Dalllas/Fort Worth and Chicago.

American Airlines drastic reaction follows the massive US$10.2m fine handed down by the FAA to Southwest Airlines after it revealed the airline had not carried out safety checks on 46 planes over a nine month period.