What are the weather requirements for LAHSO instructions to be accepted?

The weather requirements for LAHSO (Land and Hold Short Operations) instructions to be accepted are important for ensuring the safety and efficiency of airport operations. Each criterion plays a vital role in determining whether LAHSO can be implemented safely.

Firstly, the absence of windshear within 20 minutes is critical because windshear can create sudden changes in wind speed and direction, which can affect an aircraft’s ability to land safely and maintain control during smaller operational margins required by LAHSO.

Additionally, the requirement for the weather to be visually clear is necessary to ensure that pilots can maintain visual separation and situational awareness. Clear visibility allows pilots to see both the runway ahead and any other aircraft that may be operating nearby, thereby reducing the risk of accidents when executing LAHSO operations.

Lastly, prohibiting LAHSO on contaminated runways is also essential for safety, as contaminated surfaces can significantly impair braking performance and increase stopping distances. By avoiding LAHSO in these conditions, the risk of runway overruns or other incidents is minimized.

Therefore, all these factors combined dictate that LAHSO instructions can only be in effect under specific weather conditions that ensure safety, confirming that the correct answer encompasses all of these requirements.