(Reuters) - American Airlines said on Thursday that its regional carrier PSA had temporarily removed most of its aircraft from service and canceled flights while it works with the Federal Aviation Administration (FAA) to address a maintenance issue. “Out of an abundance of caution, PSA Airlines has temporarily removed most of its aircraft from service in order to complete a necessary, standard inspection on the nose gear door,” a spokeswoman said. She said the issue was discovered earlier on Thursday, prompting the cancellation of 230 flights. Inspections for more than 90 aircraft have been done and the remainder will be completed before Friday. American Airlines said it was working through an operational plan for Friday and would know more later tonight. Any cancellations will be on account of crew availability, the spokeswoman said. “PSA Airlines removed a number of its Bombardier regional jets from service after discovering a maintenance item that required immediate attention,” the FAA said in a statement. “The airline voluntarily disclosed the matter to the FAA, and the agency is working with the airline to address the situation,” it said. PSA is one of three American Airlines’ wholly-owned regional subsidiaries that operate a significant share of the carrier’s domestic flights.