Southwest Airlines plans to offer its pilots reduced hours and, in effect, monthly pay, two people familiar with the matter said, as it grapples with higher costs and overstaffing due to delays in aircraft deliveries from Boeing. The Dallas-based airline, which operates an all-Boeing fleet, has been reeling from the U.S. planemaker's ongoing safety crisis. Last week it warned of a hit to earnings as it expected to receive just 20 Boeing aircraft this year, less than one-fourth of its original plans.