When will the ALIS application display a red circle for the aft index?

The ALIS (Autonomic Logistics Information System) application utilizes a color-coded system to indicate the status of the aft index in payload distribution. A red circle signifies a condition that requires attention, specifically related to the acceptable range of the aft index values for payload distribution.

In this context, the correct answer reflects the circumstances under which the aft index values fall outside the desired operational limits. The system displays a red circle when the aft index is less than 1 or more than 99, indicating that the values are either too low or exceed the maximum allowable limit. This is critical in maintaining aircraft safety, performance, and balance during operations. When the aft index is outside this range, it indicates potential issues with weight distribution, which could adversely affect the aircraft's flight characteristics and safety.

Options involving values that fall within a normal range, such as exactly 0 or values in between 11-20, would not trigger a red circle. Similarly, while a value of exactly 100 is technically outside the acceptable range, the key point of the correct answer focuses on the lower and upper extremes of the index, where immediate attention is necessary. Thus, understanding these operational parameters is vital for effective management of payload distribution and ensuring safe flight operations.