For the fourth quarter 2019, Spirit’s total operating revenue was US$969.8 million, an increase of 12.4% compared to the fourth quarter 2018, driven by an 18.6% increase in flight volume. Fourth quarter 2019 revenue includes approximately US$7.2 million of out-of-period revenue related to the reclamation of over-remitted Federal Excise Tax.
Total operating revenue per available seat mile (TRASM) for the fourth quarter 2019 decreased 3.6% compared to the same period last year. Without the out-of-period revenue, the Company estimates its fourth quarter 2019 TRASM would have been down about 4.3% year-over-year. The decrease in TRASM was driven by lower operating yields, as load factor for the period was up slightly.
For the fourth quarter 2019, total GAAP operating expenses increased 16.3% year over year to US$845.2 million. Adjusted operating expenses for the fourth quarter 2019 increased 16.1% year over year to US$840.2 million. Primary drivers of the increase in adjusted operating expense compared to the fourth quarter last year include increased flight volume and higher ground handling rates.
Aircraft fuel expense increased in the fourth quarter 2019 by 6.7% year over year, due to a 14.8% increase in fuel gallons consumed, partially offset by a 7.1% decrease in fuel rates.
Net income for the quarter was US$81.2 million, compared to US$85.0 million the previous year.