F9DEN→CLT

Frontier flew 214 of the 2,813 flights on DEN to CLT, about 8% of it. Its 86.7% on time is 4 points better than the route as a whole, which runs 82.4%. Ranked by on-time rate it is first of five carriers on the route, where the range runs from Frontier at 86.7% to Southwest at 70.1%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. American Airlines arrives on time 85.1% of the time; United Airlines manages 77.6%. Sample sizes sit next to every figure, because a two-point gap across 675 flights means less than a ten-point one.

Badly late arrivals are rare here: only 4.7% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The 1,337 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The return leg is a different operation and performs like one: it runs 76.9% on time across 215 flights, 10 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 10 points of difference.

One caution: this is a thin sample. 214 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.