Air Force personnel take part in recovery efforts at a village in Pocheon, Gyeonggi Province, Monday, four days after two KF-16 fighter jets accidentally dropped bombs there during a training exercise. Yonhap

The Air Force had three decisive chances to correct errors that could have prevented last week's accidental airstrike on a civilian area, but all were missed, according to a preliminary probe report on the incident released on Monday.

It appears that human error, compounded by inadequate oversight of the overall training process, was the primary cause of the unprecedented accidental bombing of civilians by South Korean fighter jets.

The accident occurred last Thursday during joint live-fire drills with the U.S. military in Pocheon, Gyeonggi Province. Two KF-16 fighter jets, each carrying four air-to-ground MK-82 bombs, mistakenly dropped them on a residential area, injuring over 30 people and damaging more than 100 properties.

According to the report, pilots preparing for the mission entered the coordinates for the planned strike a day before the incident. The lead pilot of the KF-16 squadron read out the route coordinates, including the target location, while the second pilot, who would be flying the second aircraft, entered the figures into the joint mission planning system (JMPS).

However, the target coordinates were entered incorrectly. It remains unclear at this stage whether the first pilot misread them or if the second pilot entered them incorrectly, according to Air Force officials.

Either way, by procedure, the pilots should have rechecked the coordinates, but they failed to do so, marking the first missed opportunity to correct the error.

On the day of the drill, before takeoff, the pilots transferred the operation data from the JMPS onto a storage device for the jets. Due to an equipment malfunction, the pilot of the second aircraft had to manually enter the target coordinates in the cockpit.

This led to a discrepancy: the lead aircraft carried the incorrect coordinates from the previous day, while the second jet had the correct ones. During the final pre-flight inspection, both pilots reviewed the target coordinates again, but the lead pilot failed to notice the error. This was the second missed opportunity.

The most critical mistake occurred during the actual flight.

Although the lead pilot noticed slight differences between the flight path and the target area's terrain compared to previous training exercises, he proceeded with dropping the bombs.

In a rush to meet the designated time on target, the pilot failed to visually confirm the target but still reported "target in sight" and dropped the bombs. The second pilot, focused on maintaining formation with the lead aircraft, failed to recognize the first pilot's mistake and proceeded with dropping bombs at the wrong coordinates, even though he had the right figures.

Air Force Chief of Staff Gen. Lee Young-su bows while issuing a public apology during a briefing at the Ministry of National Defense in Seoul, Monday, after Air Force fighter jets accidentally dropped bombs on residential areas last Thursday. Yonhap

In response to mounting criticisms, Air Force Chief of Staff Gen. Lee Young-su issued a public apology and vowed to overhaul the flawed practices in the training system.

"This accident should never have happened and must not occur again," Lee said during a briefing. "All the responsibility for the accident lies with me, as the chief of staff. We will reflect on the shortfalls, rectify the flawed practices and make sure this kind of incident never occurs again."

He also told reporters that following a thorough investigation, the pilots would face penalties in accordance with regulations.

However, the commander emphasized that the pilots' mistakes were not the only cause of the accident.

"A flaw in operational procedures, including superiors failing to properly oversee flight preparedness, also played a role," Lee said.

According to preliminary findings, the squadron commander and battalion commander — who were responsible for supervising aircraft readiness, especially given that the training involved live bombs —failed to fulfill their duties.

In response, the commander vowed to strengthen procedures for cross-checking the target coordinates before takeoff and overhaul the overall reporting system.

The Air Force, which had temporarily suspended flight missions except for reconnaissance and urgent operations since the incident, will gradually resume flights in coordination with the ongoing annual Freedom Shield exercise with the U.S. military, which began Monday.

But live-fire drills will remain suspended until preventive measures are fully implemented.

A truck is damaged in Pocheon, Gyeonggi Province, Friday, a day after KF-16 fighter jets accidentally dropped multiple MK-82 bombs there during a military exercise. Korea Times photo by Shim Hyun-chul