What is a condition under which LAHSO cannot be accepted?

LAHSO, or Land and Hold Short Operations, is a set of procedures that allows for more efficient use of available runway space during landing and takeoff, but it is subject to specific conditions for safety. One of the critical limitations is the risk of windshear, which can dramatically affect an aircraft's performance and handling during approach and landing.

If windshear has been reported within the last 20 minutes, this is a significant safety concern because windshear can lead to sudden changes in airspeed and may compromise the pilot's control of the aircraft. In such conditions, accepting LAHSO could create an unsafe situation, as pilots may need full use of the runway in case of a go-around or other emergency maneuver. Therefore, the reported windshear makes it unsafe to proceed with LAHSO at that time, highlighting the importance of ensuring optimal safety when performing these operations.

The other conditions mentioned, such as a dry runway, a tailwind condition, or favorable weather parameters like a ceiling above 2000 feet and visibility of 6 statute miles, are conditions under which LAHSO may still be accepted provided that they do not conflict with existing operational limitations.