What is the maximum slope degree at which an aircraft can land?

The correct answer is "None," indicating that there is no established maximum slope degree for aircraft landings due to variability in aircraft capabilities and operational conditions. Different aircraft have different performance characteristics, which affect their ability to land on sloped terrain.

While some aircraft can handle slopes up to 15 or even 20 degrees, the specific limits depend on factors such as aircraft weight, type, and the environmental conditions at the time of landing. The term "maximum slope" can also be subjective since "landing" can occur under various circumstances, which may not be standardized across all types of aircraft.

Therefore, the phrase "None" appropriately encapsulates the complexities of slope degrees for landing, indicating that a universal limit does not apply across different aircraft types and landing scenarios.