WASHINGTON ( CNN ) -- Southwest Airlines will pay $ 7.5 million to settle complaints that it flew unsafe aircraft , and the fine will double unless the airline completes additional safety measures within a year , federal regulators announced Monday . The FAA found Southwest operated jets on nearly 60,000 flights without performing certain mandatory inspections . The Federal Aviation Administration originally recommended more than $ 10 million in civil penalties in 2008 after finding Southwest operated 46 of its Boeing 737 jets on nearly 60,000 flights without performing mandatory inspections for fatigue cracks in their fuselages . FAA documents obtained by CNN found that in some cases , Southwest aircraft flew for 30 months after government inspection deadlines had passed . A congressional panel concluded the planes were `` not airworthy , '' and two FAA whistle-blowers said agency managers let the airline conduct the safety checks on a slower schedule to avoid disrupting flights . The Dallas , Texas-based airline said it was happy to have settled `` all outstanding issues with the FAA . '' `` This settlement with the FAA will allow us to focus on safety going forward , rather than on issues that are now behind us and that have already been addressed , '' Southwest Airlines said in a written statement . CNN 's Mike M. Ahlers contributed to this report .
Fine will double unless Southwest completes additional safety measures within a year . Investigation found Southwest flew the aircraft without checking for fatigue cracks in fuselages . FAA documents : Aircraft flew for six months after inspection deadlines passed . Southwest happy to have settled ` ` all outstanding issues with the FAA ''