What does adequate slack in a wire bundle compensate for?

Adequate slack in a wire bundle is primarily intended to compensate for mechanical vibrations. In an aircraft, components are subjected to various forces such as turbulence, engine vibrations, and other mechanical stresses during operation. If the wires are too tightly bundled together without sufficient slack, vibrations can cause fatigue, leading to potential damage or failure of the wires over time.

When slack is present, it allows the wires to move slightly in response to these vibrations without putting undue stress on any individual wire or connection. This flexibility helps maintain the integrity of the electrical system, ensuring that connections remain secure and that insulation does not wear away.

Thus, while environmental changes, wear and tear, and fluctuations in electrical load are important considerations in aircraft wiring, the specific purpose of having adequate slack is primarily to handle the mechanical challenges presented by vibrations.