Which factor increases the engine inlet hazard distance by 20%?

The factor that increases the engine inlet hazard distance by 20% is strong wind conditions. Specifically, wind speeds above 25 knots can lead to a significant shift in how airflow interacts with the aircraft's engines. Inlet hazard distance refers to the area around an aircraft where hazards may occur due to the engine's intake forces, which can be affected by external conditions such as wind.

When winds reach or exceed 25 knots, the dynamics of airflow change, potentially causing debris or loose materials on the ground to become entrained, which could pose a danger if ingested by the engines. Additionally, the performance and stability of the aircraft during takeoff and landing can be influenced by this level of wind speed, resulting in a larger defined area where caution must be practiced. This makes the aircraft operations more susceptible to risk, thereby necessitating an increase in the distance designated as an inlet hazard zone.

In summary, winds of 25 knots create conditions that warrant a 20% increase in the engine inlet hazard distance due to the increased risk associated with higher wind velocities affecting aircraft safety.