Allegiant Airlines, which came under special scrutiny by federal safety regulators last year, said operations are improving after it increased spending on safety management, training facilities and younger aircraft.

“We’re investing in everything we know to invest in,” Chief Operating Officer Jude Bricker told reporters Wednesday. “Most of the indicators we watch are positive. Everything is moving in the right direction.”

The U.S. Federal Aviation Administration stepped up oversight at some areas of the airline last year after a mechanical failure caused the nose of an Allegiant jet to rise off the ground prematurely before takeoff from Las Vegas, defying the crew’s attempts to push it down. The carrier later discovered that a critical piece of equipment in the tail of the Boeing Co. MD-83 had come loose.

FAA officials said in October that the agency intensified its scrutiny of Allegiant’s “flight operations and aircraft maintenance programs” as a result. When the airline inspected all its MD-80s after the incident, it found three jets with bolts that weren’t properly secured to aircraft control systems, according to repair logs obtained by Bloomberg.

Outside Auditor

Following last year’s incidents, Allegiant hired an outside auditor to review its safety programs and regulatory compliance and invested in an extensive safety database and risk assessment system. It also has added pilot training beyond FAA requirements, actively encouraged employees to report concerns and stepped up oversight of contractors that work on engines, airframes and aircraft components.

The airline said it’s seen a decrease in the rate of flight interruptions — maintenance-caused diversions, turn backs after takeoff or aborted takeoffs in excess of 80 knots — to 1.37 per 1,000 flights in March from 2.81 per 1,000 in April 2015. Engine failure rates are steady or declining, said Eric Gust, vice president for operations.

The carrier, a unit of Allegiant Travel Co., also said it’s resolving a pilot shortage that stemmed from adding flights faster than it could train employees.

Reports about last year’s difficulties have led to more questions from passengers about safety issues, Bricker said. The Las Vegas-based airline will operate 333 daily nonstop flights at 113 airports as of July, primarily ferrying passengers from smaller cities to leisure destinations such as Las Vegas, San Francisco and New Orleans.

While sales haven’t fallen, “we take it on faith” that the incidents discouraged some travelers from flying Allegiant, Bricker said.

FAA Reprimand

The FAA reprimanded Allegiant last year because of a July incident in which two of its pilots declared they were so low on fuel they needed to make an emergency landing in Fargo, North Dakota. The agency issued a formal letter of correction, something short of an enforcement action, in which the agency could assess a civil fine. Allegiant said it implemented new procedures and training after the incident.

The Aviation Mechanics Coalition, a nonprofit that was previously aligned with the Teamsters union, issued a report last month saying it documented 98 instances of preventable maintenance issues during a five-month period at Allegiant, including 35 related to engine function. About 12 percent of the affected flights were diverted and 16 percent returned, said the report, which covered September 2015 to January 2016.

“I’m confident all of the write-ups we got were absolutely correct,” Chris Moore, chairman of the coalition, said in an interview Thursday. “I know we don’t have all of them. Based on the reports I got, it looks to me very much the same as it did almost two years ago. That doesn’t mean those systems aren’t in place and won’t pay dividends at some point.”

Fleet Renewal

Allegiant is retiring its oldest planes — the MD-80s with an average age of 26 years and Boeing Co. 757-200s at nearly 23 years — and replacing them with younger used planes made by Airbus Group SE.

The carrier will add 23 Airbus A320s to its fleet by 2018 and remove the MD-80s by early that year, said Tom Doxey, vice president of fleet and corporate finance. Eventually, Allegiant will fly only Airbus A320s and A319s.

The FAA currently is conducting a National Certificate Holder Evaluation Program at Allegiant. The agency conducts the review at all airlines at specific intervals.

©2016 Bloomberg L.P.

This article was written by Mary Schlagenstein from Bloomberg and was legally licensed through the NewsCred publisher network.