A pilot's rapid descent while returning to base during a December mission in support of Operation Inherent Resolve caused his fatal crash in Jordan, according to an accident investigation board report released the Air Force announced Monday.

Capt. William H. DuBois Jr., a well-regarded F-16 pilot with the 77th Expeditionary Fighter Squadron, deployed to the region on Oct. 14 to conduct airstrikes targeting the Islamic State group in Iraq and Syria. He had flown 18 flights as part of the operation. Seventeen of those flights took place at night, including five where he landed at night.

On Dec. 1, DuBois and his wingman took off at about 4:20 a.m. local time, flying the entire time at night. The aircraft was outfitted for strike missions, including four 500-pound bombs, four air-to-air missiles, two external fuel tanks and multiple targeting pods.

Shortly after taking off, the wingman radioed to DuBois that he had a landing gear door malfunction. The crew circled the base to burn off fuel and prepare to land.

The first pilot was able to land safely, and DuBois followed. It was still night out, and while DuBois was outfitted with working night-vision goggles, it isn't clear if he was using them.

Pilots with the squadron had flown many night approaches since deploying, and had established a practice to compensate for a lack of radar on approach. Pilots would begin their approach to the airfield later than what was outlined by squadron guidance, and would use instruments to help guide the aircraft down when normally they would rely on radar. The move would have the aircraft land more quickly, according to the report.

The move became standard among the pilots, but violated published procedures and guidance, according to the report.

"Despite published [squadron] guidance to the contract, this 'self set-up' approach by members of the [squadron] was a common practice within the squadron," the report states.

Leaders had taken steps to stop pilots from setting up their own approaches in this way, but they had not been effective.

On this flight, DuBois set up his approach closer to the landing strip and at about 3,500 mean sea level. He continued to descended quickly, and turned into a "dog leg" maneuver to intercept the approach course at about 2,300 mean sea level, well below the minimum altitude requirementof about 4,000 feet mean sea level, according to the report.

Because he was flying so low, DuBois the pilot was unable to recognize and recover from the descent. After pulling out of the turn, about one second before hitting the ground, DuBois apparently was able to see he was too low and attempted a 4G level pull away from the ground, but it was too late. He crashed at 4:58 a.m.

The F-16 was destroyed, at a loss of $30.8 million. There were no other injuries or damages to civilian property. A host nation recovering helicopter launched to recover his remains and bring them back to the U.S.

DuBois grew up in New Castle, Colorado, and graduated from the University of Colorado at Boulder, where he was a part of the school's Reserve Officer Training Corps.

"He was the best man I ever knew," his father, William DuBois Sr., said in a statement following the crash. "He had a short life that was so well-lived. He lived life to the fullest. He was so much more."

DuBois had a total of 741 hours of flight time. Commanders had said he would likely be the next in his squadron to be picked for the U.S. Air Force Weapons School.