Hidden damage involves the inspection of a disassembled unit. In some cases, unsafe conditions in an aircraft may be present as a seemingly functional item may quickly become inoperative caused by defects not easily seen on a Preliminary Inspection. Besides the inspection and repair of obvious damage in a unit, areas adjacent to the damage are inspected and addressed accordingly. While a unit is disassembled, the tops, bottoms, and sides of all assemblies should be inspected for hidden damage that could include heat, corrosion, poor workmanship, or other environmental damage.