Osan’s first joint, combined IRON RADR exercise improves airfield restoration capabilities

Published May 1, 2025
By Staff Sgt. Kahdija Slaughter
51st Fighter Wing Public Affairs

OSAN AIR BASE, Republic of Korea --

The 51st Civil Engineer Squadron hosted the first ever complex, joint and combined IRON RADR exercise at Osan Air Base, Republic of Korea, April 24, 2025.

The primary goal of the exercise was to test and evaluate the preparation and burial of temporary shelters while teams of U.S. Air Force, U.S. Army, ROK Air Force and ROK Army engineers conducted rapid airfield damage repair operations – simultaneously the RADR teams practiced responding to several simulated attack scenarios.

The IRON RADR exercise is all about increasing survivability of our RADR teams

Lt. Col. Andrew Myers, 51st CES commander, USAF

“The IRON RADR exercise is all about increasing the survivability of our RADR teams,” stated U.S. Air Force Lt. Col. Andrew Myers, 51st CES commander.

The 51st Fighter Wing’s “Fight Tonight” mission is to defend the base by generating combat airpower; this requires the airfield to be fully operational at a moment’s notice – and restored to fully operational status if it receives damage during an attack.

The 51st CES is responsible for making restorations quickly and efficiently through the RADR process.

Members of the U.S. Air Force, U.S. Army, Republic of Korea Air Force and ROK Army level the dirt recently packed into a large crater in an airfield pad during IRON RADR at Osan Air Base, Republic of Korea, April 24, 2025. IRON RADR is the first complex, joint and combined exercise on Osan AB that tests, evaluates and prepares civil engineers to safely conduct rapid airfield damage repair operations in a simulated contingency environment. One large and six small craters were repaired in less than eight hours; enhancing the U.S.-ROK partnership, ‘Fight Tonight’ mission capabilities, and interoperability for contingency operating bases across the Korean peninsula. (U.S. Air Force photo by Staff Sgt. Kahdija Slaughter)

It’s no secret that an airfield is a wide open space vast enough for clear lines of sight in two directions; east to west in the case of Osan AB. If damaged, the RADR teams could be vulnerable to attack until the repairs are complete.

Heavy equipment and pavements experts say the RADR process allows engineers to repair multiple damaged areas simultaneously and in less time.

“Specifically, a typical large crater repair to an airfield could take up to 12 hours, but when we execute RADR, we can get it done in six,” said U.S. Air Force Tech. Sgt. Thomas Meyer, 51st CES pavements and equipment operator and RADR instructor.

That means RADR teams would need to survive and operate on the airfield for six hours.

“Whether it's against ground attacks or small armed drones that could interfere with operations, we’re developing novel concepts for how we will protect our forces,” explained U.S. Air Force Maj. Shawn Pennie, 51st CES operations commander.

Members of the 51st Civil Engineer Squadron place a cargo container in a berm ditch during IRON RADR at Osan Air Base, Republic of Korea, April 24, 2025. The IRON RADR exercise included preparing and burying expedient shelters while teams of U.S. Air Force, U.S. Army, ROK Air Force and ROK Army engineers completed rapid airfield damage repair operations and simultaneously responded to several simulated attack scenarios. (U.S. Air Force photo by Staff Sgt. Kahdija Slaughter)

Force protection solutions implemented during the exercise include v-ditches and berms, as well as cargo containers. A berm is an earthen wall used by military personnel as a temporary barrier of protection when under attack. A v-ditch is a type of berm that takes the shape of its namesake.

“Think of a v-ditch as the most basic form of protection against fragmentation from munition that would strike in the area, as well as some blast waves from the impact,” explained U.S. Air Force Capt. Tyler Stout, 51st CES installation management flight commander. “Additional overhead cover from cargo containers is a solution that could give more effective protection from airburst munitions that disperse harmful chemical agents.”

On exercise day, the 51st CES successfully buried two cargo containers near the damaged airfield pad, allowing U.S. Army Soldiers assigned to the 11th Engineering Battalion, ROK engineers assigned to contingency operating bases across the Korean peninsula, and over 200 personnel from various units across the 51st FW to take shelter during simulated attack scenarios.

Members of the U.S. Air Force, U.S. Army, Republic of Korea Army, and ROK Air Force exit a berm ditch after a simulated air attack during exercise IRON RADR at Osan Air Base, Republic of Korea, April 24, 2025. Rapid airfield damage repair is a process for repairing structural damage on airfields to restore combat airpower generation. The team of civil engineers, logistics technicians, vehicle maintainers, explosive ordnance technicians and emergency medical responders worked together to repair craters in a damaged airfield pad enhancing U.S.-ROK partnership and displaying interoperability in action. (U.S. Air Force photo by Staff Sgt. Kahdija Slaughter

Members of the U.S. Air Force, U.S. Army, Republic of Korea Army, and ROK Air Force exit a cargo container after receiving an all clear notification during IRON RADR at Osan Air Base, Republic of Korea, April 24, 2025. Rapid airfield damage repair is a process for repairing structural damage on airfields, quickly restoring combat airpower generation when needed. Force protection solutions implemented during the exercise included v-ditches, berms, and cargo containers. (U.S. Air Force photo by Staff Sgt. Kahdija Slaughter)

Months before the exercise happened, teams of planners and subject matter experts prioritized instructional and hands on training classes for joint and combined RADR personnel; increasing familiarity with 51st CES heavy equipment and sharing best tactics, techniques and procedures for conducting legacy and rapid pavement repairs, as well as explosive ordnance operations.

The 51st CES explosive ordnance disposal flight contributed to the realism of the exercise by destroying the foundation of an airfield pad, effectively creating the damages received from a simulated air-to-ground attack that would kick off the exercise.

“Our main goal was to make the most realistic scenario that [RADR teams] would see in a wartime environment,” expressed U.S. Air Force Tech. Sgt. Gerardo Perez, 51st CES, EOD technician. “So we used C4, TNT, and dynamite to create six small craters with ground upheaval and land disbursement – mimicking the damage that could be created by ballistic missiles and airfield penetrator munitions.”

U.S. Air Force Tech. Sgt. Gerardo Perez, 51st Civil Engineer Squadron explosive ordnance disposal technician, carefully creates a charge hole in a C4, TNT, and dynamite ordnance at Osan Air Base, Republic of Korea, April 18, 2025. Several explosives were placed in concrete and asphalt holes, creating a realistically damaged airfield for the first complex, joint and combined IRON RADR exercise. The rapid airfield damage repair mission encompasses advanced pavement repair techniques and strategies that support airfield operations in degraded and contingency conditions, allowing swift restoration of combat airpower generation capabilities no matter the warfighting landscape. (U.S. Air Force photo by Staff Sgt. Kahdija Slaughter)

U.S. Airmen assigned to the 51st Civil Engineer Squadron explosive ordnance disposal flight set off several explosions on a controlled airfield pad in preparation for the first complex, joint and combined IRON RADR exercise at Osan Air Base, Republic of Korea, April 18, 2025. Rapid airfield damage repair is a process for repairing structural damage on airfields to restore combat airpower generation. The contributions of the EOD Airmen enhanced the realism and complexity of IRON RADR. (U.S. Air Force photo by Staff Sgt. Kahdija Slaughter)

Members of the U.S. Air Force, U.S. Army, U.S. Marine Corps, and Republic of Korea Air Force examine small craters and foreign object debris created by the 51st Civil Engineer Squadron explosive ordnance disposal flight during a joint and combined EOD training at Osan Air Base, Republic of Korea, April 18, 2025. The training created an instructional and hands-on environment to learn and execute tactics, techniques, and procedures when creating explosive ordnances. The detonations prepared during the training laid the realistic foundation needed for a complex rapid airfield damage repair exercise called IRON RADR. (U.S. Air Force photo by Staff Sgt. Kahdija Slaughter)

The realism continued on exercise day with various units across Osan converging their isolated programs and strategies into one complex effort.

The 51st CES EOD Airmen created blasts to simulate continued air-to-ground attacks, bombs, and grenades sent by adversaries. The 51st Security Forces Squadron provided ground security, engaged against simulated ground attacks, and participated as simulated enemy forces using armed drones and automatic weapons to ambush the RADR pad.

Emergency responders from the 51st Medical Group stood by to conduct ambulatory care if needed and the 51st Logistics Readiness Squadron provided vehicle maintenance, ground transportation and fuel to all heavy equipment.

“I learned a lot during the exercise today,” said U.S. Army Staff Sgt. Justino Peguero, 11th Engineering Battalion heavy equipment operator. “We implemented different ways to take shelter in case we receive contact from enemy forces. Some of the locations were trenches in the ground, inside [cargo containers], behind berms and even behind the heavy equipment if we were too far away from an expedient shelter.”

U.S. Soldiers assigned to the 11th Engineering Battalion and U.S. Airmen assigned to the 51st Civil Engineer Squadron mix flowable concrete fill during IRON RADR at Osan Air Base, Republic of Korea, April 24, 2025. The rapid airfield damage repair mission encompasses advanced pavement repair techniques and strategies that support airfield operations in degraded and contingency conditions, allowing swift restoration of combat airpower generation capabilities no matter the warfighting landscape. (U.S. Air Force photo by Staff Sgt. Kahdija Slaughter)

U.S. Soldiers assigned to the 11th Engineering Battalion pause rapid airfield damage repair operations to take cover behind heavy equipment during IRON RADR at Osan Air Base, Republic of Korea, April 24, 2025. The goal of IRON RADR was to test, evaluate and prepare joint and allied engineers to respond to simulated threats during repair operations; increasing survivability from continued air and ground attacks. (U.S. Air Force photo by Staff Sgt. Kahdija Slaughter)

Members of the U.S. Air Force, U.S. Army, Republic of Korea Army, and ROK Air Force construct a fiber reinforced polymer mat during IRON RADR at Osan Air Base, Republic of Korea, April 24, 2025. Rapid airfield damage repair is a rapid process for repairing structural damage on airfields, quickly restoring combat airpower generation when needed. The exercise included preparing and burying temporary shelters while teams of engineers collaboratively worked to restore the airfield and simultaneously respond to several simulated attack scenarios. (U.S. Air Force photo by Staff Sgt. Kahdija Slaughter)

“I think everyone in the [643rd Engineering Construction Company at Camp Humphreys] needs this knowledge, especially being forward deployed here in Korea. If attacked, we would be working with the Air Force, ROKA, and ROKAF to restore the airfield. So, strengthening those relationships and being on the same page is super important,” expressed Peguero.

Reflecting on the broader impact of the exercise, strengthening the relationships and resilience of Airmen, Soldiers, and ROK partners, Pennie emphasized the critical link between rapid airfield recovery and success of the ‘Fight Tonight’ mission:

“The faster we can fix an airfield, the faster we can launch jets and continue to execute operations. And ultimately that’ll increase our survivability here [at Osan] because we’re able to defeat and degrade our enemy’s ability to attack us.”