Airplane wire insulation. Hand unrolling and applying airplane wire insulation. The insulation is being unrolled from a storage spindle (centre left) and then wrapped around a bundle of wires (bottom centre). Gloves are required to keep the equipment clean. Aircraft wiring needs insulation to protect against fire and also to shield them from electromagnetic interference, both from the surrounding equipment and external sources. There are many kilometres of wiring inside a typical passenger jet airliner, both for the aircraft controls, and for in-flight entertainment systems.