Corrosion control: Prolonging the life of Osan’s aircraft
OSAN AIR BASE, Republic of Korea -- The bulk of the Air Force’s aircraft fleet are several decades old, so preventive maintenance is very important to the mission. A simple wash down and paint touchup can prolong the life of a jet.
Aircraft structural maintenance Airmen from the 51st Maintenance Squadron perform these maintenance procedures in the corrosion control shop, also known as the “paint barn.” They identify, remove and treat corrosion using mechanical and chemical procedures.
“Metals have a tendency to return to their natural state,” said Tech. Sgt. Sameth Mao, 5st MXS NCO in charge of corrosion control. “Being outside in the elements and even time can accelerate the corrosion factor. It’s a man-made object so it will always corrode.”
Corrosion is a natural process that causes refined metals to convert to more stable elements and compounds such as oxygen and hydroxide. Prolonged exposure to air starts the process, so a sealed layer of advanced protective coating paint is required for proper prevention.
According to studies performed by Bio Water Synergistics, a company that specializes in aerospace wash equipment for the military, up to 80 percent of maintenance costs during an aircraft’s life span can be attributed to corrosion, hence the importance of corrosion-control procedures.
Aircraft are washed down every 90 days to remove the dirt, grime and grease built up during flight that can hide any chips or gouges in the paint.
“The advanced protective coating is expected to last for 10 years,” said Staff Sgt. Alan Johnson, aircraft structures maintainer. “Per the AFI, every 10 years the aircraft are repainted, but required touchups are often done in the meantime.”
When aircraft go through phase, they are thoroughly inspected for scrapes and gouges in the paint coating which might require touchups after the maintenance is complete. If any are found, the aircraft is delivered to the corrosion shop for the required painting.
“After we figure out which areas of the aircraft we need to paint, we’ll start masking, putting down tape and paper, off all the areas that cannot be painted,” said Johnson. “Once all areas are masked, we sand the areas feathering and blending any chipped or nicked areas to provide a smooth surface so the finished product looks even.
“After sanding is complete we wipe the areas to be painted to remove all dust and debris, and once the areas are clean we spray a light coat of primer,” continued Johnson. “When the primer has dried we spray the top coat then let it dry.”
Mao explained that from start to finish, it takes about five work days to completely sand, prime and paint an aircraft, then another 72 hours for the paint to properly dry or “cure.” For the coating to dry properly the hanger must being kept between 60-90 degrees Fahrenheit.
Once all preventive maintenance procedures are completed the aircraft is deemed serviceable and returned to active status.
Corrosion control’s aircraft structural maintainers extend the life of each aircraft system that they work on keeping Osan’s aircraft presentable and mission ready to fight tonight.