Which of the following factors affects the Allowable Cargo Load?

The correct factor that affects the Allowable Cargo Load is altitude above sea level. As altitude increases, the air density decreases, which can impact the performance of the aircraft and its engines. This means that at higher elevations, the aircraft may have a reduced capacity for carrying cargo because the lift generated is not as efficient as it would be at lower altitudes. Consequently, pilots and planners must consider altitude when calculating the permissible weight of cargo to ensure safe operation.

While the type of cargo does influence how it is loaded and secured, it does not directly impact the defined Allowable Cargo Load in the same manner as altitude. Operational readiness, although important, refers more to the aircraft's status for missions rather than its capacity to carry weight. Likewise, the age of the aircraft might affect its overall performance and maintenance needs but is not a direct factor in calculating the immediate payload capacity for a flight. Understanding how environmental factors, particularly altitude, play a significant role is essential in aviation logistics and safety planning.