South Korea’s Air Force in 2026: The Fleet Facing the North

The best jet in South Korea’s air force is the F-35A stealth fighter. The Republic of Korea Air Force (ROKAF) flies 39 of them, has 20 more on order, and has made them part of the Kill Chain, its plan to strike North Korean missiles before they launch.

Behind the F-35s sit 59 F-15K Slam Eagles, about 167 F-16s and a homegrown light attack jet. The last F-5s from the 1970s and 1980s are due to retire by the end of 2027, and the country’s own fighter, the KF-21 Boramae, joined the air force on September 22, 2026.

This guide ranks every combat and lead-in jet the ROKAF flies by fighting value as of October 2026, then covers the KF-21, the radar planes and tankers, the US Air Force bases next door, and how the fleet really compares with North Korea’s.

1. F-35A Lightning II: The First-Strike Fighter

The F-35A tops the list because it is the only stealth fighter in Korean service and the spearhead of the Kill Chain. Seoul bought 40 in 2014 in a deal worth about $7 billion, roughly $175 million per jet.

The first two landed at the 17th Fighter Wing in Cheongju on March 29, 2019, and the Korea Times dates the first batch to 2019 through 2022. The US Air Force rates the F-35A at Mach 1.6, about 1,200 mph, with a range of more than 1,350 miles (2,170 km) on internal fuel.

One of the 40 will never fly again, which is why the fleet stands at 39. In December 2023 Korea signed for 20 more in the newer Block 4 configuration, due from 2027, which will take the stealth fleet to about 60.

2. F-15K Slam Eagle: The Long-Range Hammer

The F-15K is a Korean version of the American F-15E Strike Eagle, a two-seat jet built to carry heavy weapons a long way. Korea ordered 40 for delivery from 2005 and a second batch of 21 in 2008, and 59 remain after two fatal crashes, in 2006 and 2018.

It ranks second because it brings range and payload the F-35 cannot match from internal bays. The USAF rates the F-15E at 1,875 mph (3,018 km/h), better than Mach 2.5, and the Korean jets fly from Daegu with the 11th Fighter Wing.

They are getting a deep rebuild. The US approved the upgrade in 2024 at an estimated $6.2 billion, covering 70 AN/APG-82 AESA radars and 70 EPAWSS electronic warfare suites.

Boeing then won a $2.806 billion contract in early 2026 for the design and development work, which runs to the end of 2037. The air force expects to fly the F-15K until 2060.

3. KF-16 and F-16C/D: The Workhorse

The F-16 is the most numerous fighter in Korea. Wikipedia’s inventory lists 118 single-seat KF-16C/U jets and 49 two-seat KF-16Ds, a mix of older Block 32 F-16s and 140 Block 52 KF-16s produced under license by KAI, the first delivered in December 1994.

In 2016 Lockheed Martin won a $1.2 billion contract to upgrade 134 of them to the F-16V standard with an AESA radar. The upgraded jets are called KF-16U, and Korea’s Monthly Aviation reported in 2023 that the work was planned to finish in 2028.

The fleet has had a hard two years. A KF-16D crashed on takeoff at Red Flag-Alaska in June 2025, and on February 25, 2026, an F-16C from Chungju went down near Yeongju after two jets touched during a night battle-damage check. Both crews ejected.

4. FA-50 Fighting Eagle: The Homegrown Light Fighter

The FA-50 is a light combat jet built by Korea Aerospace Industries on the T-50 trainer airframe. Sixty were ordered for the ROKAF for delivery from 2013 to 2016, and KAI rates it at Mach 1.5.

It cannot match an F-16 for radar or range, but it is cheap to fly and was bought to replace the aging F-5s. It ranks above the F-5 because it is newer and faster, and the air force bought it specifically to take the older jet’s place.

5. KF-5E/F Tiger II: The Last Cold War Jets

The F-5 is a 1970s light fighter, and Korea received 340 of them over the years, including 48 KF-5Es and 20 KF-5Fs assembled locally from 1982. Counts of the survivors range from 61 in a 2024 Korean report to 48 in May 2026, all now gathered at Suwon.

Their days are numbered. In May 2026, Air Force Chief of Staff Gen. Son Seok-rak said the F-5 would retire before the end of 2027, three years ahead of the original 2030 date, as the KF-21 arrives to replace it.

The F-4 Phantom beat them to it. Korea’s last three F-4Es retired at Suwon on June 7, 2024, 55 years after the type arrived in 1969, from a peak of up to 190 jets.

The F-5’s most remembered moment is a sad one. On January 11, 2022, Maj. Shim Jeong-min’s F-5E got fire warnings on both engines after takeoff from Suwon. Instead of ejecting he steered toward a hillside, crashing about 330 feet (100 m) from a village in Hwaseong. He did not survive.

6. T-50, TA-50 and T-50B: The Supersonic Trainers

Korean fighter pilots train on the T-50 Golden Eagle, a supersonic jet built by KAI. The air force flies 72 T-50s and 22 armed TA-50 lead-in fighters, with 20 TA-50 Block IIs on order.

Ten more are T-50Bs flown by the Black Eagles, the air force’s eight-jet aerobatic team at Wonju. They won both the King Hussein Memorial Sword and the As the Crow Flies award at the Royal International Air Tattoo in 2022 and displayed in Australia for the first time at Avalon in 2023.

The inventory also lists 103 KT-1 Woongbi turboprop trainers and armed KA-1s.

The KF-21 Boramae: Delivered, Not Yet Operational

On September 22, 2026, the first production KF-21 flew from KAI’s plant in Sacheon to Yecheon Air Base, joining the 156th Fighter Squadron of the 16th Fighter Wing. The squadron, a former F-4 unit, was reactivated on June 1, 2026, to fly it.

The KF-21 is a twin-engine fighter that first flew on July 19, 2022, with a top speed of Mach 1.81, about 1,370 mph (2,200 km/h). Korea is building it to replace its old F-4 and F-5 fleets.

It is not in this ranking yet because one jet is not a combat force. The air force says it will declare the KF-21 operational in the second half of 2027, with 40 air-to-air Block I jets due by 2028 and 80 Block IIs with long-range ground-attack missiles by 2032.

Its AESA radar is Korean, but its engines are American, General Electric F414s assembled in Korea.

The Eyes and the Reach: Radar Planes, Tankers and Spy Jets

Four E-737 Peace Eye radar planes, Korean versions of Boeing’s E-7 Wedgetail, were delivered between 2011 and 2012 and have suffered low availability. Their successors are four Bombardier Global 6500 business jets carrying an Israeli EL/W-2085 radar, picked in 2025 in a deal L3Harris valued at more than $2.26 billion and due by 2032.

Four KC-330 Cygnus tankers, the Airbus A330 MRTT, arrived from November 2018 to extend the fighters’ reach. Korea plans to buy up to two more, with a tender expected in the second half of 2026.

Four RQ-4 Block 30 Global Hawk drones, delivered between December 2019 and September 2020, watch North Korea from high altitude. Signals intelligence comes from Hawker 800 Peace Pioneer jets in service since 2001 and two Falcon 2000S aircraft, with four new Falcon 2000LXS-based Baekdu-II aircraft contracted for completion by the end of 2026.

Transports and the Presidential 747

The airlift fleet is 12 C-130H Hercules, four C-130J-30s and 18 CN-235s, flown by the 5th Air Mobility Wing at Gimhae. Korea ordered three Embraer C-390 jet transports in December 2023, and the first is due in December 2026, with the other two by December 2027.

The president flies on Code One, a Boeing 747-8i the air force leases from Korean Air, in service since January 2022. In June 2026 the government said it would extend the lease by five years when it expires in January 2027, at about 300 billion won, rather than buy a plane.

The US Air Force Next Door

The ROKAF does not face the North alone. The US Air Force runs two major bases in South Korea: Osan, near Pyeongtaek, home to the 51st Fighter Wing and Seventh Air Force headquarters, and Kunsan, home to the 8th Fighter Wing, the Wolf Pack.

The A-10s that flew from Osan since 1993 left in 2025, and an experiment that concentrated F-16s at Osan ended on September 28, 2026, when Seventh Air Force announced the jets would return to Kunsan. Air & Space Forces Magazine puts the US fighter force at an estimated 72 F-16s across the two bases.

South Korea vs North Korea: Is It Outnumbered?

On paper, yes. South Korea’s 2022 Defense White Paper, the latest edition, counts about 410 South Korean combat aircraft against about 810 in the North, and 65,000 air force personnel against 110,000.

The numbers hide a generation gap. As our guide to North Korea’s air force shows, the North’s best fighter is the MiG-29, delivered in the late 1980s, and hundreds of its jets are 1950s and 1960s designs. The white paper itself warns that its table compares quantity only and actual power may differ.

Today South Korea spends heavily to keep that lead. Its 2026 defense budget is 65.86 trillion won, up 7.5 percent, and Global Firepower ranks its military fifth of 145 countries for 2026, with North Korea 31st.

The honest verdict is that South Korea fields one of the most capable air forces in Asia, built around stealth, long-range strike and a fighter it designed itself. Its weakness is age at the bottom of the fleet and readiness, not numbers, and the F-5’s retirement and the KF-21’s arrival are aimed squarely at both.