Korean Air staff wash dust off a plane at the maintenance center in Incheon International Airport, Tuesday. Airlines need to wash aircraft regularly for smooth operations, especially in spring when yellow dust strikes Korea. /Yonhap
By Kim Rahn
Almost all industries _ except the pharmaceutical industry which produces face masks _ dread the coming of the yellow dust season. This especially holds true for the airline industry.
Every spring, Korean carriers spend time and money washing dust off planes.
The surface of an aircraft is made mainly of aluminum and other non-metallic composite materials that are painted with a strong protective covering to prevent corrosion.
To remove pollutants from machine parts, airline companies must wash their aircraft regularly about once a month.
Yellow dust is one of the worst pollutants, as it becomes an oxide when reacting with moisture on the ground, corroding the aircraft’s surface and decolorizing the paint.
So planes coming from China where yellow dust originates need to be washed regularly during the spring. Aircraft from the Middle East, a desert area, are also cleaned regularly.
There are two methods of washing airplanes _ with water and with wax.
Washing an airplane with water is no different than washing a car: spray, scrub with non-polluting detergent, and rinse.
Airplane manufacturers recommend airlines do not use more than 80 pounds of water pressure per square inch (PSI) to protect the plane’s surface. They also recommend that the airlines do not to wash the engine, tires and landing devices with water.
It takes from seven to eight hours for nine people to wash a B747 jumbo jet, according to Korean air.
``The washing requires 6,000 liters of water at a cost of 3 million won,’’ a Korean Air official said.
The expenses differ according to the aircraft size.
``In order to prevent pollution, we conduct the washing work only at designated places in our maintenance centers at Kimpo, Inchon and Kimhae airports where waste water disposal plants are set up,’’ the official said.
In winter, airlines usually wash planes with a wax-based cleanser, as water can freeze.
``For the environment, we wash aircraft with wax, not with water. It takes about eight hours to wash a B747 plane which can carry 400 passengers, and six hours for a B767 flight that carries some 260 passengers,’’ an Asiana Airlines official said.
It takes an additional two hours if they wash the tires.
The cost is about half that of washing with water, she said.
There have been no reports of yellow dust causing an aircraft to malfunction, and dust blown into Korea does not largely affect the operation of a plane’s engine. But dust stuck to the plane surface can decrease the lift of the wings.
On March 21 and 22, 2002, some 100 domestic flights were cancelled due to poor visibility caused by yellow dust storms.
``Yellow dust does not have direct influence on an airplane’s operation. Most airports have good landing and takeoff facilities that allow operation with low visibility, so cancellations stemming from yellow dust are very rare,’’ a Korean Air official said.