Quite a bit of conjecture from FiveThirtyEight’s Benjamin Montet on pilots being able to make up lost time in the air, but still some interesting deductions:
When a flight is delayed by less than 30 minutes, it consistently takes between 340 and 350 minutes to travel between the East and West Coasts. But when the delay is longer — between 35 and 50 minutes — the flight time between coasts drops. Then, it only takes 320 to 330 minutes. The flight time reverts back toward six hours when the delay exceeds 50 minutes.
That means if your plane takes off 35 to 50 minutes after its scheduled departure, you can expect to make up about 20 minutes of that time in the air. But if the delay is any longer than 50 minutes, you shouldn’t get your hopes up. I suspect the pilots are more willing to press the accelerator, and consequently accept the higher fuel costs, if they believe there’s a good chance they can still get to their destination on time.
His reasoning makes sense: if you’re going to be late, why waste the fuel to be a little less late? But if there’s a chance to be on time, it may be worth it to try and make the time up.