do terminal fees cover the cost of the facility construction, maintenance and security. Any not covered expense is a free service to the airline.

Terminal fees separate, but airlines probably pay 'rental.'

to be profitable.

and that's why there are things like baggage fees now.

and they should holler FOR regulation, during which time I think they did make money, not much, but reasonable amounts were built into the picture.

and cargo as well.

also keep in mind that they have a fine upstanding tradition of going bankrupt, reorganizing, raiding pensions and so on, then coming back and making fat profits, only to do it all again a few years down the runway.

I took a pencil and some paper and figured it out.

The latest statistics I could find were from 2012, in which approximately 642 million passengers flew on domestic flights (this doesn't count foreign carriers' flights that land in the US). Multiplied by $6 per passenger, that translates to profits of $3,852,000,000.

Nearly $4 billion in profits doesn't sound all that bad when you add it up. I know they like to throw around the "six dollar" figure, because it sounds so paltry. I'm wondering how they figure that, too. I'm betting their profits are actually far better.

http://www.rita.dot.gov/bts/press_releases/bts016_13

The article is written by Richard Quest, who is CNN's expert in travel and not my go-to source for financials but likely they vetted this through someone that checks their stats and numbers.

Commercial airlines are a weird business -- subsidized, allowed to collude on pricing, very sensitive to the price of fuel -- and now they are nickle and dime over how much legroom you get or where your bag travels. I think customers' expectations for the whole air travel experience are much lower than they were 20 years ago and certainly far below the hey day of air travel, the 1960s. So the low expectations of the flying public are answered with incremental charges for options that make the overall experience very marginally better.