Go!, which set off an interisland fare war with one-way tickets as low as $39, said it lost about $1 million in its first month of operation.

The loss, which excludes $20 million in startup costs, was lower than expected, said Jonathan Ornstein, chief executive officer of Phoenix-based Mesa Air Group, which owns go!.

"We feel confident that we are on the right track," Ornstein said.

Ornstein said go! could be profitable at current fare levels if it were to use larger aircraft.

The carrier, which began flying on June 9, operates four 50-passenger Bombardier CRJ-200 aircraft, with a fifth plane for reserve. Ornstein said the company hopes to replace its local fleet with 90-seat CRJ 900s or even larger aircraft by next summer.

Ornstein said by phone yesterday that go! isn't too far from its break-even point.

The company — whose planes were 82.5 percent full and 88.9 percent on time in June — generated more than $1,700 in revenue per flight, while its costs were less than $2,000 per flight, Ornstein said.

Those numbers don't include other revenue go! receives when customers book their hotel reservations and car rentals through the airline's reservation system. The expenses reported don't include any portion of the startup costs.

Ornstein said he's not sure how long the local carrier will keep the $39 fare but said ticket prices will likely remain in the $39 to $69 range that it currently charges.

He would not say what portion of its seats sell for $39. The $1,700 per-flight revenue figures means that customers are paying an average of about $42.50 each way.

"If you look on our Web site, you'll find the $39 fares pretty easily," he said.

According to Ornstein, go!'s performance was one of the bright spots for Mesa.

On Wednesday, Mesa reported that its net income for its fiscal third quarter fell more than 36 percent because of increased expenses and severe East Coast weather conditions in June.

Reach Rick Daysog at rdaysog@honoluluadvertiser.com.