United Airlines Flew Plane That Was Not ‘Airworthy’ 23 TIMES

• United Airlines may be fined $435,000 by the FAA for not inspecting a fuel pump pressure switch after it was repaired.
• United Airlines said it is working closely with the FAA in its review.
• The FAA said the plane was flown 23 times before the inspection was completed.

The Federal Aviation Administration is proposing to fine United Airlines almost a half million dollars for flying a plane that was not in "airworthy condition."

At issue is a Boeing Dreamliner that United mechanics serviced on June 9, 2014. The airline replaced a fuel pump pressure switch in response to a problem a flight crew had documented two days before the repair. Instead of immediately performing the required inspection, the FAA said United put the plane back into service.

According to the federal government, United flew the plane 23 times on domestic and international routes before doing the required inspection of the new switch on June 28, 2014.

The FAA said two of those flights happened after the agency told the airline it had yet to perform the inspection. The agency has proposed a fine of $435,000.

"At United, the safety of our customers and employees is our top priority," Charles Hobart, a spokesman for United, told CNBC in a written statement. "We immediately took action after identifying the issue and are working closely with the FAA in their review."

FAA Administrator Michael Huerta said, "Maintaining the highest levels of safety depends on operators closely following all applicable rules and regulations. Failing to do so can create unsafe conditions."

There is no indication the failure to inspect the switch caused a problem on any of the 23 flights United made before coming into compliance with FAA rules.

The FAA said United has asked to meet and discuss the case.