Information on Safety gear

Combat Edge - Disinfectants corroding landing gear - Safety Shorts - Brief Article

The spraying of chemical disinfectants onto landing craft in Europe in order to curb the spread of foot and mouth disease could lead to corrosion in the metal and catastrophic failure, according to Commodities Directorate lead engineers Sandra Fitzgerald and Doug Wiser.

The problem has arisen because nations spraying the landing gear are using chemicals cleared by the U.S. Department of Agriculture to kill foot and mouth disease, but not cleared for the aircraft by the U.S. Air Force, according to Fitzgerald.

"Landing gear materials are really sensitive to certain chemicals. What we're finding is, in general, it requires extreme pH values to kill the foot and mouth virus and we know pH levels -- either very high or very low -- are dangerous to landing gear. The Air Force corrosion office, assisted by the folks at Brooks AFB, are testing approved landing gear cleaners against the virus," Wiser said. "What we suspect may happen is the gear needs to be submerged in solution for about 40 minutes to make sure the virus is dead. And that is just not going to happen."

The threat of the virus to European livestock is immense and has resulted in the culling of approximately 2.5 million animals in England, according to Cable News Network. The virus is so contagious it can be transported through any surface it touches, such as shoes, dirt and aircraft tires.

Impact on the landing craft could be profound and long lasting, with the full effects unknown for several years, according to Wiser. The most immediate threat is hydrogen embrittlement, which, according to Wiser, can cause a quick and catastrophic failure. Another concern is stress corrosion cracking that can occur over time. Aircraft with carbon brakes could experience oxidation and failure of those systems.

To take a proactive stance, protect landing gear by ensuring it's properly painted, masking the landing gear and lightly spraying the tires. "Unfortunately, that is not always being done. Sometimes the whole plane is being sprayed. So we're asking that they take a high volume of water at low pressure and dowse the whole gear for quite a while. Then when the plane returns to its home base, clean it again and thoroughly inspect it.

"We're also documenting every aircraft that is being sprayed -- what it was sprayed with, how long it was left on and when it happened. That way, in case something happens or starts to happen, we can get all those landing gears off the planes that have been sprayed in a similar manner.

"We've already seen some kind of failure in the commercial world. Boeing aircraft were sprayed with sodium hypochlorite (chlorine bleach) for the purpose of curbing the spread of foot and mouth disease, which resulted in the failure of the axles by stress corrosion cracking from the corrosion pits that resulted from the chlorine bleach attack," said lead engineer Clint Forrest.