[News Space=Reporter seungwon lee] Among domestic airlines operating at domestic airports in the first half of 2025, Air Seoul, a low-cost carrier (LCC) affiliate of Asiana Airlines, recorded the highest delay rate. It proudly(?) took the top spot as the tardiness king for both domestic and international flights.

The Ministry of Land, Infrastructure and Transport classifies flights that depart or arrive at the gate more than 15 minutes later than the scheduled time stated on the ticket as "delayed."

According to official statistics released by the Ministry of Land, Infrastructure and Transport and Korea Airports Corporation on July 27, a total of 329,736 flights operated across all domestic airports from January to June of this year, of which 77,700 were delayed. This brings the combined average delay rate for domestic and international flights across the ten largest airlines to approximately 23.6%. This represents a 1 percentage point increase compared to the 22.6% reported in the first half of last year.

Looking at domestic and international flight delay rates separately, domestic flights recorded a delay rate of 19.6%, with 33,306 out of 170,040 flights delayed. International flights recorded a delay rate of 27.8%, with 44,394 out of 159,696 flights delayed, a significantly higher rate than domestic flights. While the domestic flight delay rate decreased by 1.4 percentage points compared to the first half of last year, the international flight delay rate rose by 3.1 percentage points, breaking the all-time record.

By airline, Air Seoul had the highest delay rate for both domestic and international flights. Of the 7,144 flights, 2,610 were delayed, resulting in an average delay rate of 36.5%. This means that one in three Air Seoul flights either failed to depart or arrive on time.

Specifically, 687 out of 2,498 domestic flights (27.5%) and 1,923 out of 4,646 international flights (41.4%) were delayed, the highest delay rates among domestic airlines in both cases.

What's interesting is Air Seoul's delay rate compared to last year. While the domestic flight delay rate improved by 9.9 percentage points year-on-year, the international flight delay rate rose by 1.2 percentage points. Overall, the improvement was 2.9 percentage points. Prior to this, in the Ministry of Land, Infrastructure and Transport's air traffic service evaluation, Air Seoul received a B+ grade for domestic flights and a D++ grade for international flights, the lowest grade, reaffirming its weakness in on-time performance.

Other national airlines' delay rates are as follows. For domestic flights, Air Seoul (27.5%) is second, followed by Jin Air (26.3%) and Eastar Jet (24.5%). Conversely, Jeju Air saw a significant increase of 8.6 percentage points from last year, reaching 19.3%, while T'way Air saw a significant improvement of 17.5 percentage points, reaching 17.2%.

Jin Air ranked second in international flight delay rates, following Air Seoul, with 32.8% (5,706 out of 17,407 flights), followed by Air Premia at 32.4% and Asiana Airlines at 32%. Eastar Jet and T'way Air showed relative improvement, lowering their delay rates by 5.4% and 4.9%, respectively.

The delay rate for domestic flights on foreign airlines has also increased. In the first half of this year, the international delay rate for foreign airlines was 21.8%, a 2.6 percentage point increase from the previous year, indicating a slight decline in operational reliability.

Factors contributing to the rise in flight delays in the first half of this year include congestion at domestic and international airports and routes, a surge in international flights since the COVID-19 pandemic (a record 264,254 flights), and frequent turbulence due to bad weather. The Ministry of Land, Infrastructure and Transport (MOLIT) announced that it plans to actively improve punctuality and enhance the quality of aviation services by evaluating not only the number of delayed flights but also the duration of delays.

An aviation industry expert pointed out that, "In the first half of 2025, one in three flights in Korea were delayed or not on schedule, and Air Seoul, in particular, had the dishonor of having the highest delay rate for both domestic and international flights." He added, "The efforts of domestic airlines to improve their constitution to ensure punctuality and strengthen service competitiveness have emerged as more urgent tasks than ever."