The Federal Aviation Administration confirmed Wednesday that it is conducting a detailed, 90-day inspection of Allegiant Air's operations in response to "various internal issues" tied to maintenance and safety.Such a comprehensive review is normally conducted at all airlines every five years. But the FAA said it moved up its review of Allegiant by nearly two years to ensure the airline has remedied problems in operations.The review began about April 1 and continues through June.The FAA provided little detail about the reasons for the review, but said the issues were related to two flights last summer. One involved a near-crash of an aircraft in Las Vegas that suffered a jammed elevator on its tail during a takeoff that was aborted. The second involved an emergency landing in Fargo, N.D., due to low fuel at an airport that was partly closed.The FAA's review comes as Allegiant officials recently have confirmed problems with operations after a year of steadfastly insisting all was well with the airline. Allegiant CEO Maurice Gallagher Jr. last week conceded the airline had a "bad summer" in 2015, with several emergency landings at St. Pete-Clearwater International Airport.Previous coverage: Allegiant Air CEO admits to 'bad summer,' says changes will helpThe airline carried about 95 percent of the airport's record 1.6 million passengers in 2015.Gallagher announced the airline's local management team had been replaced and Allegiant would hire five mechanics to work out of Pinellas County.The airline also held a "media day" earlier this month at which officials emphasized increased spending on safety. One intent of the event was to generate positive press to counter continued reports about problems, the airline told financial analysts Wednesday as it announced quarterly earnings."We've been proactive trying to make sure the message gets out," Gallagher said. "We certainly want to be ahead of (negative reports) and do the proper thing. It's just part of our maturation process."The Allegiant pilots union, involved in bitter contract negotiations, said Allegiant's recent comments on problems are overdue."It's clear that Allegiant's bare-minimum approach to its operation isn't working," said Dan Wells, president of Teamsters Local 1224. "The federal government is conducting a high-profile investigation, and with an emergency occurring virtually every week due to a preventable maintenance issue, passengers are increasingly saying it isn't worth the risk to fly Allegiant."Allegiant officials declined to comment.The FAA's decision to move up the safety and operations review comes as the Las Vegas-headquartered airline continues to suffer apparent operational problems. On Monday, the airline canceled 10 flights, rescheduling all a day later. None of the flights was tied to St. Pete-Clearwater.Over the weekend, two Allegiant flights suffered maintenance problems.On Saturday, Allegiant technicians discovered during an overnight maintenance check that an aircraft's outer window panel was missing and that it had hit the engine where it damaged a front engine fan blade. The panel would either have fallen off in flight or as the plane taxied, the FAA said. The inner portion of the window held firm, so the cabin did not lose pressure.The FAA did not identify that flight's destination or where it originated.On Sunday, Flight 633 from Sanford, near Orlando, bound for West Virginia made an emergency landing after a low oil pressure reading led the pilots to shut down an engine, an internal Allegiant memo shows. It turned out the engine actually had adequate pressure and a sensor system had malfunctioned.By airline standards, it was a relatively minor event, even though it caused an unscheduled landing. All airlines encounter such problems. But this incident elicited a swift response from top Allegiant executives."A comprehensive investigation is under way," according to the memo to Allegiant's maintenance and operations teams by the airline's vice president of maintenance and engineering, Kurt Carpenter, and Eric Gust, vice president of operations.Allegiant officials told analysts that stories about Allegiant's well-publicized maintenance issues are still not affecting ticket sales.The airline reported $71.9 million in net income for the first quarter, up 11 percent from the same period last year. That was on $348 million in operating revenue, up 5.9 percent from 2015. The airline flew 2.59 million passengers in the quarter, up 15 percent from 2.25 million.Times staff writer Justine Griffin contributed to this report. Contact William R. Levesque at [email protected] Follow @Times_Levesque.