"150 Rotary-Wing Aircraft Passed Through My Hands" [Yang Nakgyu's Defence Club]

Only at the Beginner Level When Joining 35 Years Ago
Overnight Work Due to Unfamiliar Blueprints
Helicopter Maintenance Requests from Six U.S. Overseas Bases
Expectations for UH-60 Performance Upgrade Project

In the 1970s, South Korea faced a tremendous security crisis. The United States, advocating the "Nixon Doctrine" which emphasized "self-defense," withdrew one division of its ground forces stationed in Korea and even attempted to completely remove all U.S. troops from the country. However, at that time, the South Korean military was unable to properly manufacture even a single rifle since the Korean War. On December 26, 1971, former President Park Chung-hee delivered a top-secret memo to the Agency for Defense Development (ADD). The project was disguised under the code name "Directive to Establish a Plan for the Promotion of the Aviation Industry." Starting with this project, the South Korean military achieved the development of domestic missiles, tanks, and aircraft. The first generation of Korea’s defense industry (K Defense) led the development of domestic weapons. Now that domestic weapons have been deployed, the second generation of the defense industry is taking charge of maintenance, repair, and overhaul (MRO). We met with those who are active in the MRO market following defense exports.

"(You must) look at the blueprints precisely, understand the blueprints accurately, and execute exactly according to the blueprints. Maintenance must have zero margin of error." These are the words of Yoo Dong-jun, Deputy General Manager of the Military Aircraft Business Division at Korean Air, who is responsible for maintaining rotary-wing aircraft (helicopters) for both the U.S. and South Korean militaries. He is the first and longest-serving rotary-wing maintenance engineer in Korea. He joined Korean Air in 1989, right after graduating from Busan Technical High School where he studied sheet metal work. At that time, domestic defense companies were just taking their first steps in rotary-wing aircraft. Korean Air officially entered the aircraft manufacturing business when the late Cho Joong-hoon, founder of the Hanjin Group, was asked by former President Park Chung-hee in 1975 to participate in aircraft production. That same year, Korean Air was designated as a "military aircraft maintenance, assembly, and production defense contractor."

Deputy Director Yoo has maintained over 150 rotary-wing aircraft over 35 years, including the UH-60 supplied to the U.S. military and South Korea, and the HH-60G used by the U.S. Air Force. (Photo by Korean Air)

After serving in the Army Aviation Operations Command for one year following his employment, Deputy General Manager Yoo returned to find Korean Air had changed. Since 1991, Korean Air began producing the 15-seat medium helicopter UH-60 and supplying it to the South Korean military. The UH-60, developed by Sikorsky in the U.S. for the U.S. Army, has been produced in about 3,000 units since 1974 and is operated by approximately 30 countries. Korean Air has licensed production of 130 units to date.

Only at the Beginner Level When Joining 35 Years Ago

Deputy General Manager Yoo guided the reporter to show the maintenance site. Established in 1976, the Korean Air Tech Center is located adjacent to Busan Gimhae Airport. Covering a total land area of 707,866 square meters and a total floor area of 266,180 square meters, it is fully equipped with all necessary facilities for aircraft production. It houses over 19,000 types of jigs and tools and more than 600 advanced pieces of equipment. The area is so vast that moving between offices requires using carts or bicycles similar to those used on golf courses. In the maintenance hangar, U.S. military aircraft such as the A-10, CH-53, F-15, F-16, and CH-47 were lined up for maintenance. To date, Korean Air has maintained 3,700 U.S. military aircraft operating throughout the Pacific region. It serves as the sole comprehensive maintenance and repair depot for U.S. military aircraft.

Deputy Chief Yoo always accompanies the rotary-wing aircraft after maintenance. His flight time alone exceeds 2,000 hours. (Photo by Korean Air)

Looking at a UH-60 undergoing maintenance, Deputy General Manager Yoo continued his explanation. He recalled, "The first task I was assigned immediately after discharge was the production of the UH-60 fuselage." He added, "There were U.S. military personnel on the production line at the time, but communication was difficult, so we had to study 'work as work, English as English' separately." The U.S. military sometimes presented blueprints that were unfamiliar. The U.S. military helicopters were equipped with an aerial refueling system allowing in-flight refueling. Deputy General Manager Kim was taken aback and had to study overnight. Although the maintenance period was set at 180 days, it was shortened to 150 days. He had no time even to see his young daughters, aged 4 and 2 at the time. Sleeping briefly in the company lounge was a frequent occurrence. They also had to solve problems they had never encountered before. A U.S. military helicopter from the Kadena Air Base in Okinawa, Japan, was covered in salt deposits, which was a serious issue. They removed all the instrument panels and performed coating work.

Overnight Work Due to Unfamiliar Blueprints

The lifespan of rotary-wing aircraft is 8,000 flight hours. Every 2,000 flight hours, they must undergo depot-level maintenance (complete disassembly, inspection, and repair of parts). He said, "There has never been a problem with rotary-wing aircraft after depot-level maintenance," adding, "In many cases, the airframe and other components are replaced to extend the lifespan even after reaching 8,000 hours."

Over 35 years, more than 150 rotary-wing aircraft have passed through his hands. The main models are the UH-60 supplied to both the U.S. and South Korean militaries and the HH-60G model used by the U.S. Air Force. After maintenance, South Korean military helicopters undergo a 20-hour test flight, and Deputy General Manager Yoo always accompanied these flights. He wanted to verify everything personally. His total flight time exceeds 2,000 hours.

Helicopter Maintenance Requests from Six U.S. Overseas Bases

Deputy General Manager Yoo’s passion for maintenance did not stop there. In 2005, the HH-60G model operated by the U.S. military in Alaska experienced engine problems. Maintenance in the U.S. mainland would have taken over a year. The U.S. military transported the HH-60G on a massive C-17 military transport aircraft to Korean Air. Yoo and his team worked overnight to complete all maintenance within the promised 180 days. Even the U.S. military was impressed, giving high praise. Following this, word spread among overseas forces, and Korean Air began receiving requests. The U.S. military brought helicopters from six overseas bases. The U.S. Air Force requested repairs for helicopters stationed at the Laken Heath base in the United Kingdom. In total, Korean Air has maintained about 76 overseas rotary-wing aircraft.

Expectations for UH-60 Performance Upgrade Project

The South Korean military plans to proceed with a performance upgrade project for the UH-60 (24 units for Army Special Forces) and HH-60 (12 units for Air Force search and rescue). The budget is 961.3 billion KRW. Korean Air plans to enter this project in partnership with LIG Nex1, a defense company developing avionics, electronic warfare, and communication equipment. Deputy General Manager Yoo is highly optimistic. Recently, he has been dedicating all his time after work to creating videos to share the know-how he has accumulated over the years. Since design changes and problem-solving during performance upgrades are challenging, he hopes to help younger colleagues overcome difficulties. Yoo proudly stated, "Korean Air and I have watched over the UH-60 from its inception," adding, "Our know-how accumulated over more than 30 years is unmatched by anyone."

This content was produced with the assistance of AI translation services.