The Federal Aviation Administration proposed a US$735,000 civil fine against Mexico's Volaris, saying the airline flew 121 passenger flights on a plane that was not in compliance with U.S. regulations.
The FAA said it told Volaris in March 2013 that required safety inspections for a U.S.-registered Airbus A319 had not been performed, the agency said in a statement released Friday. The inspections involved an emergency slide and weight and balance calculations.
Volaris flew the plane on 121 passenger flights before bringing it into compliance, the FAA said.
"The traveling public relies on airlines to ensure that airplanes are properly maintained, which includes paying close attention to all maintenance requirements," FAA Administrator Michael Huerta said in the statement.
The company has 30 days to respond to the FAA letter.