By DAVID KOENIG
AP Airlines Writer
DALLAS (AP) — Labor unions are pushing U.S. airlines not to buy back their own stock. The unions want the airlines to spend money instead on hiring more workers and fixing problems that are causing widespread flight delays and cancellations. The unions said Thursday that the four largest U.S. airlines spent more than $39 billion on stock buybacks from 2014 through 2019 rather than making investments to help employees and passengers. American, United and Southwest say they have no plans to buy back stock when a prohibition against buybacks ends Sept. 30.