In this articleUALAALA pilot performs a walkaround before a United Airlines flightLeslie Josephs/CNBCU.S. passenger airlines have added nearly 194,000 jobs since 2021 as companies went on a hiring spree after spending months in a pandemic slump, according to the U.S. Department of Transportation. Now the industry is cooling its hiring.Airlines are close to their staffing needs but the slowdown is also coming in part because they're facing a slew of challenges.A glut of flights in the U.S. has pushed down fa ...