U. S. airlines were notified this week that an investigation is underway into whether they complied with an emergency order requiring flight cuts at 40 major airports during the record government shutdown, the Federal Aviation Administration said Friday. The FAA warned in letters sent Monday that the airlines could face fines of up to $75,000 for each flight over the mandated reductions, which fluctuated between 3%, 4%, and 6%. The airlines have 30 days to provide documentation showing they in...