Final answer:
The cautionary range on the Airspeed Indicator (ASI) is depicted as a yellow arc, indicating safe speeds in smooth air and cautioning pilots against abrupt control movements and high-speed aerodynamic effects.
Step-by-step explanation:
The cautionary range on the Airspeed Indicator (ASI) is typically depicted with a yellow arc. This range indicates speeds that are safe only in smooth air and where the pilot should avoid abrupt control movements. Operating the aircraft in this range is permissible, but it comes with a caution to be vigilant for high-speed aerodynamic effects or the onset of undesirable flight characteristics, such as buffeting, which may precede a stall or structural stress.
In some aircraft, this range can also indicate the transition between normal operating speeds and those speeds that would only be used in certain flight conditions, such as in a dive. It’s important for pilots to understand all the markings on the ASI, as they provide critical information for the safe operation of the aircraft.