Airline Weekly had some great stats this past week comparing the capacity of airlines in their top 10 cities between the fourth quarter of 2014 and fourth quarter of 2015.

Year-over-year American Airlines has increased capacity only in Miami (4%) and Los Angeles (7%) among their top 10 cities. They’ve shrunk operations 4% in Philadelphia. They have 40 fewer mainline jets year-over-year, but have added seats into aircraft and thus remain fairly steady in capacity offered.

American is seeing profits rise as a result of fuel costs falling more than other carriers, since they weren’t hedged (meaning they hadn’t locked in fuel prices at a higher cost than the current market, the way their competitors did). That’s good, because the merger pushed up US Airways labor costs, after all. Their non-fuel costs are rising while revenue per available seat mile has falled 6% – 8% year over year. They’re bearing the brunt of Southwest’s growth at Dallas Love Field, and they aren’t growing.

United, which shrunk total departing seats 3% in Los Angeles, has grown 9% in Denver, 12% in Boston, and 5% at Newark. Their operating margins, while improved, still lag those of their major competitors.

Delta has grown a whopping 22% year-over-year in Seattle, 9% at LAX, and 7% at New York JFK (slightly balanced by a 2% drop at LaGuardia). Delta now offers better than one-third the capacity of Alaska Airlines in Seattle. And of course they’re doing that while remaining on-time and reliable, and distributing less valuable miles.

Southwest is up 30% at Dallas Love Field – no surprise with the lifting of Wright Amendment restrictions there. They’ve grown 8% in Denver, 7% at Houston Hobby, and 4% in Los Angeles. They are the 4th largest carrier in departing seats at LAX behind American, Delta, and United respectively.

Alaska Airlines has grown 10% in Seattle as it faces down competitor Delta. It’s grown 31% at LAX and is the 5th largest carrier there (though only 38% the size of Southwest’s presence at the airport). It’s grown 8% in Portland and 7% in San Diego. Among its top markets it has scaled back only in Las Vegas (4%).

JetBlue grew 7% at JFK, 5% in Boston, 18% in Ft. Lauderdale, and 9% in Orlando. Presumably seat growth comes from adding more seats into aircraft.

Spirit‘s major growth has come at Chicago O’Hare – their second biggest city behind Fort Lauderdale – as well as Las Vegas, Detroit, Houston Intercontinental, Atlanta (where they are up 158%, in conjunction with Detroit growth explaining Delta’s basic economy fares), and LAX where they are the number six airline.

Frontier has pulled back 22% in Denver while growing operations substantially in:

• Orlando 139%
  
• Las Vegas 175%
  
• Chicago O’Hare 214%
  
• Atlanta 172%
  
• Philadelphia 1594%
  
• San Francisco 78%
  
• Miami 836%

It’s interesting to see Frontier focus on high-cost Miami versus Spirit’s home of Fort Lauderdale. Meanwhile the combined invasion of Frontier and Spirit into O’Hare and Atlanta is a big deal for fares in those cities (while Southwest contracts in the former Airtran base).

Dallas, Atlanta, Seattle, Chicago, and Los Angeles are all seeing intensified competition. Only United has scaled back the number of seats they’re offering at LAX. With this new competition fares are starting to fall as well.