if a standard automotive bolt in the U.S. is being secured, then the safety wire when installed should put tension on the bolt in a clockwise direction, since that is the direction that the bolt turns to tighten. When drilling a fastener, the choice of where to drill it depends on the type of fastener and to what it will be wired. The alternative to drilling holes in fasteners is to use safety wire tabs (see Safety wire tabs section below), or to purchase pre-drilled fasteners. AC43.13-1B, par. 7-124 f. page 7-21 specifies "Safety wire ends must be bent under and inward toward the part to avoid sharp or projecting ends, which might present a safety hazard." The first picture in this article does not conform to proper techniques and practices and ought to be replaced with a better example. Witness wire A more simplistic application of safety wire, more commonly referred to as witness wiring, is the use of light gauge, single strand, copper wire to provide positive visual confirmation of the security or closure of specific equipment within the aerospace industry. Common applications include the security of safety equipment such as fire extinguishers, and safety equipment bags, but also as an assurance that critical system switch covers remain in place, such as those associated with the application of fire suppression, or ejection systems. This application of witness wires is widely varied, and may cover a broad range of types of equipment and numerous situations. Witness wires also serve the purpose of providing a rapid method for ensuring critical safety equipment or systems have not been used or tampered with since their last repair, reset, or inspection, and also that the container of such equipment has not been inadvertently opened, disturbed or tampered with, therefore providing confidence in their readiness for use. In a similar manner, critical system switch covers are protected from inadvertent activation, through the application of witness wire. The gauge of copper wire utilized in this application is such that the wire security can be overcome with minimal breaking force by hand, without damage to the equipment or persons, and once broken, remains affixed to the equipment without the introduction of foreign object damage (FOD). Typically the wire is threaded through existing holes in the associated equipment, using a single strand loop, and a single crossover, such that the closure is secured without impedance to the