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Preventing a repeat of the Air Force’s friendly-fire incident

Published: 19 Mar. 2025, 00:04

Chang Seh-jin

The author is a professor emeritus of economics at Inha University.

The Korean Air Force’s investigation into the friendly-fire incident on March 6 in Pocheon, Gyeonggi, revealed that the cause was a coordinate input error by the KF-16 fighter pilots. The pilot manually entered 14 coordinates into the aircraft’s system. Since each coordinate consists of 15 digits, this amounted to a total of 210 digits. A single mistake — entering a "0" instead of a "5" — led to the erroneous bombing of a civilian area.

A house lies damaged after the Air Force discharged eight bombs onto Pocheon, Gyeonggi, during a live-fire exercise on March. 6. [NEWS1]

Such input errors could have been prevented with a well-established technology known as checksum verification. The principle is simple: a checksum, a condensed value derived from the 15-digit coordinate, is appended to the coordinate upon input. The system then recalculates the checksum using the same algorithm. If the recalculated checksum does not match the appended value, the system automatically rejects the input and prompts for correction. Though its purpose differs, the checksum mechanism is similar to the verification method used in Korean resident registration numbers.

With a single-digit checksum, the probability of detecting an input error for a single coordinate is 90 percent. While not foolproof, it would still have prevented 90 percent of such critical misfires.

The likelihood of human error increases exponentially when multiple coordinates are entered. However, checksum technology significantly reduces undetected errors by chaining the checksums of consecutive coordinates —much like blockchain technology. If the checksum for a single coordinate detects errors 90 percent of the time, the probability of failing to detect an error drops to 1 in 100 for two coordinates, 1 in 1,000 for three, and so on. With 14 coordinates, as in the Pocheon incident, the probability of failing to detect an error would have been as low as 1 in 100 trillion. In other words, such an error could have been virtually eliminated.

Korean Air Force Chief of Staff Lee Young-su and Air Force officials bows after delivering a public apology in Yongsan District, central Seoul, on March 10. [YONHAP]

The key advantage of a checksum system is that it forces verification. According to the Air Force’s report, the pilot did not cross-check the inputted data against the original due to a printer malfunction. Additionally, no verification was performed when uploading the data to the fighter jet. The pilot even called out “target confirmed” before releasing the bombs without visually confirming the target. A checksum system would have been far superior to these flawed self-checks, as it mandates automatic verification.

As a preventative measure, the Air Force announced that it would implement a cross-verification system for coordinate input procedures. While this may help, it is crucial to first investigate why existing cross-verification mechanisms failed. The second pilot correctly put in the coordinates but still followed the lead aircraft in dropping bombs on the incorrect target. The squadron leader failed to notice that the two aircraft had deviated from formation, and ground monitors also failed to detect this deviation. Each layer of the verification process failed, and every instance must be meticulously examined.

Whether self-checking or cross-checking, most verification processes tend to be post-incident accountability measures. If no accident occurs, failures to follow protocol often go unnoticed, leading to complacency. Therefore, critical verification steps should be enforced in real time, much like a checksum system. In other words, unless verification is properly conducted, the process should not proceed to the next step. Moreover, personnel should be empowered to halt operations or training if verification steps are not followed.

Another underlying issue may be the hierarchical command structure of the military, which can hinder horizontal communication. One way to enhance the flow of safety information is to adopt a near-miss reporting system, similar to those introduced by construction firms following the implementation of Korea’s Serious Accidents Punishment Act. This system encourages the reporting of incidents that nearly result in disaster or suggestions for accident prevention, with rewards for proactive participation. The U.S. Air Force and NATO widely utilize similar programs. Given the gravity of the Pocheon incident, the Korean Air Force should seriously consider implementing such a system.

Air Force's KF-16 fighter jet [AIR FORCE]

The bombs mistakenly dropped by the KF-16s had an explosive radius the size of a football field. Eight bombs were dropped, yet miraculously, no lives were lost. It was, at best, a fortunate outcome amid misfortune.

This incident must serve as a wake-up call. I strongly recommend implementing checksum verification for coordinate inputs. Additionally, a thorough analysis must be conducted to understand why existing cross-verification systems failed. Finally, introducing a Korean Air Force near-miss reporting system could play a crucial role in preventing future accidents.

Translated using generative AI and edited by Korea JoongAng Daily staff.