What information is required before using a cable rigging chart?

• A. The weather forecast and wind speed
• B. Ambient temperature and cable size
• C. Aircraft color and tail rotor type
• D. Battery voltage and engine type

Answer: (B)

Cable rigging charts are used to determine the proper tension and sag for a cable under static conditions. The inputs you must know before using the chart are the ambient temperature and the cable size. Ambient temperature matters because it affects the cable’s length and stiffness, which in turn changes tension for a given amount of sag. The cable size matters because different diameters behave differently under load, so the chart has specific curves for each size. The other factors listed don’t enter into the chart calculations: weather forecast and wind speed relate to environmental conditions during flight, not the ground-based rigging calculation; aircraft color and tail rotor type are unrelated to rigging data; battery voltage and engine type don’t affect cable tension or sag in this context.