Spirit Airlines A320. Courtesy, NK

Florida-based Spirit Airlines (NK) reported first-quarter net income of $23.4 million, almost tripled from a net profit of $7.9 million in the year-ago period.

Spirit president and CEO Ben Baldanza credited the airline’s network expansion as the reason for the result. “Robust demand for our ultra-low base fares with a range of optional services for a fee resulted in our revenue growth outpacing our capacity growth,” Baldanza said in a statement.

Revenue was up 29.6% to $301.5 million while expenses increased 28.4% to $264.3 million, producing an operating profit of $37.2 million, up 38.7% from $26.8 million in the year-ago quarter. NK said the operating performance was “primarily due to increased flight volumes and higher fuel expense,” which increased $27.8 million during the quarter.

Traffic rose 18.8% to 2.2 billion RPMs on a 17.7% increase in capacity to 2.6 billion ASMs, producing a load factor of 84.8%, up 0.8 point. Yield increased 9.1% to 13.74 cents as RASM rose 10.1% to 11.65 cents and CASM increased 9.2% to 10.21 cents. CASM ex-fuel was 5.99 cents, up 5.6%.