A: Flying leads refers to an electrical cable or wire not permanently attached to a device or equipment. Instead, it has one or both ends left unconnected, allowing it to be easily connected or disconnected as needed. These leads are typically used in prototyping, testing, or temporary installations, where the connections change frequently. The term “flying” indicates its ability to be moved or adjusted freely.

Sometimes sub-assemblies are manufactured with flying leads since they must be hard-wired to another assembly. Aerospace PCBs and modules often are designed to be permanently soldered to another assembly instead of using a connector. It is less costly, and the connection is free from the effects of vibration. Whenever a connector can be avoided, it saves money. It also ensures a solid and highly reliable connection eliminating the possible movement of connector pins.