The use of electrical conductivity measurements in detecting heat and fire damage in aircraft structure

Many aircraft components and structures are manufactured from aluminium alloys. Thermal damage to aircraft can occur due to fire, lightning strikes or through leaking hot air ducting. When an aluminium alloy is subjected to an extraneous heat source and then cooled, a change can occur in its electrical conductivity which may be related to the materials hardness or strength. Conductivity instruments operating under the principles of eddy current induction provide a non-invasive means of detecting these changes. Conductivity measurements may thus be used as a basis for the assessment of integrity of an aluminium alloy following suspected or known heat damage