The indispensable subscription-only Airline Weekly ran numbers looking at year-over-year revenue and costs for various airlines in the third quarter, and the difference between those figures, rank ordering carriers.

It was interesting to see which airlines built up the biggest gaps between increased revenue and reduced cost.

Here are the very best performers:

And the very worst:

Aegean is Greece, Gol and Copa are dealing with cyclical and structural weakness in South America generally. I’m not familiar with the story of rising costs at Nok Air or collapsing revenue at TransAsia.

United and American outperformed Delta by this measure — they saw their costs decline more (11% and 12%) than Delta (7%) though their revenue declined more (-2% and -4% versus -1%). American is certainly under revenue pressure from Spirit, which has it’s own problems — a 2% increase in costs despite declining fuel prices. Spirit fired its CEO a few days ago.

The gap between Allegiant – at the very top of the list – and stagnating Spirit underscores that there reaches a point where ultra low cost carriers are no longer well-positioned to cherry pick routes and must face serious competition from larger airlines. They battle it out on price, but the larger carriers can offer a better product and greater frequencies making it a difficult battle to win… especially when facing rising costs themselves.