Individual part protection is being adopted on aircraft superseding older methods of final overhaul in which coatings were applied after assembly and installation.
Special attention is given to aluminum alloy structure design to eliminate moisture collecting depressions and areas.
Electrical battery installations pose special problems. Control cables passing through pressure bulkheads wear off corrosion protection. Effect of exhaust gases on structure is well understood. Food buffets are a major problem because of food and liquid spillage. Protection from lavatory and wash water corrosion is not completely satisfactory.
Magnesium in power plants causes problems and undrained low spots corrode. Dissimilar metals in engines must be studied for corrosive effects. Radiators, feed valves, ignition systems and injectors need watching on this score.
The trend to steel propellers requires added steps in overhaul to protect abraded leading edges. Moisture under deicer boots must be watched. Improper heat treatment results in intergranular corrosion.
Varied sources of water used on aircraft necessitates careful placement of ground station filters, softeners, demineralizers or stills.
