The airlines, which face a combined $605,000 in penalties, have 30 days to respond to the proposed fines. The FAA has stepped up fines on the aviation industry after being accused of inaction.

Eagle, based in Fort Worth, may be penalized $330,000 after inspectors found that it had flown two planes with seats that would not stow into the upright and locked position, the agency said Wednesday.

Continental, part of Chicago-based United Continental Holdings Inc., faces a $275,000 fine after operating two Boeing Co. 737-900ER planes on 73 flights with incorrect landing gear wheel-tire assemblies installed, according to the FAA. Both carriers have 30 days to respond to the proposed fines.