There are signs, however, that the run of lower airfares made possible by cheaper jet fuel is ending.
American Airlines expects a key revenue per seat figure to rise between 1.5 percent and 3.5 percent in the first quarter after falling throughout 2015 and 2016, and other carriers are close behind.
For the airlines, it looks like the good times will keep rolling.
Last year, U.S. airlines carried a record 823 million passengers and earned $22.3 billion in pretax income, down just $1 billion from the stellar results in 2015.
Pretax profit margins topped 14 percent in both 2015 and 2016. That's the closest the industry has ever been to the U.S. corporate average 15.8 percent last year according to their trade group.
As profits have recovered from the 2008-2009 financial crisis, U.S. airlines have paid down $63 billion in debt, bought hundreds of planes, added the equivalent of nearly 33,000 full-time employees, and raised wages.
The average salary at U.S. airlines last year was $80,900, or 38 percent above the private-sector average, according to the airlines' trade group. That number is skewed by high salaries for pilots many airline employees earn less than the average