When conducting CAT II operations, what is the required visibility standard for a 100-foot decision height?

In CAT II operations, the visibility standard is crucial for ensuring safe landings, particularly when the decision height (DH) is as low as 100 feet. For a 100-foot decision height, the required visibility standard is 1200 RVR (Runway Visual Range). This visibility level allows pilots to maintain adequate visual references to the runway environment during the approach phase, ensuring that they can safely execute a landing even in lower visibility situations.

Maintaining this RVR standard provides enough visual cues for pilots to make informed decisions regarding landing while relying on the aircraft's autopilot systems that may be engaged during these operations. If the visibility were lower than 1200 RVR, it would compromise the safety of the approach and landing, possibly requiring the flight to go around or divert to an alternate runway with better conditions.

In summary, the requirement of 1200 RVR at a 100-foot decision height ensures a balance between safety and operational capability during low visibility conditions in CAT II operations.