SOMEWHERE OVER OHIO—Some airline flights are just losers—day after day, they just can't get to their destination on time. And the worst flight of all?

That would be United Express Flight 4352, what's meant to be a 97-minute jump from Cincinnati to Newark, N.J. The 6 p.m. flight has run chronically late more often than any other U.S. airline flight over the past two years, according to Department of Transportation data.

Newark...