Australia’s Virgin Blue has reached an agreement “in principle” with Boeing to order up to 50 new 737s, Virgin Airlines Group CEO Brett Godfrey said in a statement released today. “We do not intend to shy away from remaining competitive, and we plan to vigorously defend our core domestic markets,” said Godfrey, who also noted that Virgin Blue plans to secure “additional short-term domestic capacity.”

Flying a fleet of 62 Boeing 737-700/800s, 21 Embraer 170/190s and four Boeing 777-300ERs as of December 31, the Brisbane-based low-fare airline announced a net profit of A$62.5 million ($56.2 million) for the second half of last year, compared with a loss of A$101.4 million ($91 million) during the same period a year earlier.

Along with “favorable fuel movement,” the company cited a 4.5-percent drop in non-fuel-related cost per-available-seat-kilometer (CASK)—achieved through various internal cost-cutting and productivity initiatives—for the dramatic turnaround.