Billionaire Larry Ellison’s nearly three-year run as the owner of Island Air ended awash in red ink.

The state’s second-largest airline, which changed majority ownership in February, lost money all 11 quarters under Ellison to finish with a $50.4 million deficit, according to data released Monday by the U.S. Department of Transportation.

Island Air ended 2015 with a fourth-quarter loss of $4.5 million en route to a full-year loss of $20.7 million. Both figures were better than the losses of $10.4 million and $21.1 million, respectively, in the fourth quarter and full year of 2014. Island Air’s 2016 first-quarter data will be released next month.

Honolulu venture capitalist Jeffrey Au, head of two investment groups that bought the majority interest in Island Air, did not respond to requests for comment Monday.

The airline, which was down to two routes during the fourth quarter — Honolulu-Maui and Maui-Lanai — saw revenue plunge 26.4 percent to $6.2 million from $8.4 million in the year-earlier quarter. For the year, revenue sank 20.5 percent to $27.5 million from $34.6 million in 2014.

“We continue to make good progress in moving Island Air forward as we build on the successful restructuring and turnaround efforts that the airline focused on for most of last year,” the company said in a statement. “We continue to see improved performances in all areas of the company, including operational performance and safety. These efforts have put Island Air in a strong position to expand service to the people of Hawaii, as evidenced by our restoration of service to Kauai as of March 15 and our new service to Kona that will begin on June 14. In addition, we are in the advanced negotiations to lease additional aircraft.”

In January, shortly after the purchase, Island Air submitted a regulatory filing with the Securities and Exchange Commission indicating that the company had raised $10 million.

On April 22, President and CEO Les Murashige and Chief Operating Officer Rob Mauracher left the company. Au has not offered any reasons for their departures, but named Chief Commercial Officer David Uchiyama as interim president and CEO.

Other recent moves by the new ownership included restarting Honolulu-Lihue service March 15 after a nine-month absence, dropping Maui-Lanai service March 31 due to low demand, and announcing plans to start flying between Honolulu and Kona on June 14 for the first time since 2012.

Local aviation historian Peter Forman speculated that the reason for the management shake-up might have stemmed from a difference in philosophy.

“The departure of two top executives from the airline indicate they were not on board with the desired plan for the airline,” Forman said. “Since both of them worked for the airline previously, obviously the plan for the airline would be different than existed during their tenure. Apparently there must have been a difference of opinion on how the airline should be run. Ultimately, Island Air needs to align its management with the strategy that it plans to implement.”

Uchiyama decline to comment Monday on the CEO transition, but said, “I can tell you financially we’re moving forward as planned. I was meeting with new hires today, and we’re starting a flight attendant class tomorrow (Tuesday).”

Island Air said in a statement that it attributed a significant portion of the losses last year to the suspension of service to Lihue as well as one-time costs related to the strategic restructuring of the airline and work related to the company’s first-ever safety certification by International Air Transportation Association safety auditors.

In April 2015 Island Air announced it was cutting 20 percent of its workforce, reducing service and indefinitely postponing a decision to bring in a new fleet.

Island Air currently operates five 64-seat ATR 72 turboprops.

“I don’t know if they’re making any money with their five airplanes,” Colorado-based airline consultant Mike Boyd said. “That’s a lot of short-haul flying, and you’ve got to put a lot of people on the airplane and offer frequency, which means you’re going to have a lot of empty seats from time to time.”

Hawaii Kai resident Franco Mancassola, founder of short-lived interisland carrier Discovery Airways (1989-90), said Island Air will need more money and planes.

“Island Air will need around $100 million in cash and line of credit to do what is needed,” Mancassola said. “If they don’t move rapidly, the little market that they have will erode, and consumer confidence will be lost. In addition, a visionary and competent management is urgently needed. Island Air needs to think bigger. They will need at least eight aircraft to meaningfully compete, and they need it soon.”