By The Associated Press

Two executives with pilot licenses were flying the Allegiant Air jet that made an emergency landing at a closed airport because it nearly ran out of fuel.

Allegiant spokeswoman Jessica Wheeler said Thursday that management pilots routinely operate flights to maintain their pilot certification and track day-to-day operations.

Vice president of flight operations Greg Baden and director of flight safety Michael Wuerger were at the controls of the July 23 flight with 144 passengers on board, the airline said. The identity of the pilots was first reported by the Las Vegas Review-Journal.

The plane left Las Vegas more than an hour behind schedule, according to tracking service FlightAware.com. The airline said that's because a passenger had a medical emergency in Las Vegas and had to be taken to a hospital. By the time it reached its intended destination of Fargo, North Dakota, that airport was temporarily closed so the Navy's Blue Angels flight team could practice for an air show.

According to a LiveATC.net recording, one of the pilots told an air traffic controller that he didn't have enough fuel to reach another airport and couldn't even wait 20 minutes — he would declare an emergency and land. Federal rules require airliners to carry enough fuel to reach their destination or an alternate airport with a reserve of 45 minutes worth of fuel. The plane landed safely in Fargo.

Wheeler said the pilot meant he had less than 20 minutes before dipping into the 45-minute reserve. She added that Allegiant believed that the Fargo closure included an exception for scheduled passenger flights. She said the company believes the executive did nothing wrong in their operation of the flight.

The Las Vegas-based airline, a unit of Allegiant Travel Co., said it is cooperating with investigators from the Federal Aviation Administration.