Until 2001, all F-16’s were manufactured with wiring harnesses that contained Kapton insulated wires. In May 2001, Lockheed Martin asked the companies who were making F-16 wiring harnesses to replace Kapton insulated wires with TKT insulated wires. Kapton is a DuPont tradename as is TKT. TKT stands for Teflon/Kapton/Teflon.
Kapton is a light-weight insulation with many great mechanical and electrical properties. Kapton was the predominate insulation used on aircraft beginning in the 1970’s. Although Kapton has many great properties it does experience hydrolysis (meaning it absorbs water). Hydrolysis can lead to stiffness and after it has aged, Kapton can be prone to chafing problems. Kapton can also experience arc tracking.
Arc tracking is an event where two or more wires experience an arcing event such that a fierce fire (like an explosion) burns along the outer insulation of the wires. If two or more wires have breeches in their insulation (see InterConnect’s blog about breeches in wire insulation) then an electrical arc (or a short circuit) can occur. In this video F-16 wires are purposely nicked to show what arc tracking of Kapton insulated wire looks like.
As you see in the video, arc tracking can be a long event that can cause a tremendous amount of damage to: (a) a wiring harness bundle, (b) the aircraft systems, and (c) the aircraft as a whole. The sad fact also, is that it could mean the loss of the lives of the airmen. Obviously, arc tracking is a safety of flight issue and one not well known in the aerospace community. For more information about arc tracking or to see more videos showing arc tracking of F-16 Kapton wire, please contact InterConnect’s sales team at +1.817.377.9473.