Which of the following best describes a 'life-limited' part?

A 'life-limited' part is specifically designed to operate only for a predetermined number of flight hours or operational cycles before it must be replaced. This limitation is established to ensure safety and reliability, as certain components can experience wear and degradation over time that may not be visible during routine inspections. Thus, once the maximum flight hours or cycles are reached, the part must be replaced to prevent potential failure and ensure the continued airworthiness of the aircraft.

The other choices do not accurately capture the definition of a 'life-limited' part. For example, a part that can withstand any operational cycles does not have a defined lifespan and wouldn't necessitate replacement based on time or usage. Similarly, a part that requires annual inspection may be critical for safety, but it does not inherently have a life limit based on hours or cycles. Lastly, a part that is not critical for flight safety may still be subject to different inspection and maintenance requirements but does not meet the criteria for being life-limited.