When may a Category II ILS limitation be removed?

The removal of a Category II ILS limitation is tied to the successful completion of specific operational criteria that demonstrate preparedness for such procedures. Specifically, the correct answer indicates that all pilots must have conducted three Category II ILS approaches to a decision height of 150 feet or lower, followed by successful landings. This requirement ensures that flight crews are adequately trained and proficient in making the necessary decisions during low visibility operations, which are characteristic of Category II ILS approaches.

Successful completion of these approaches not only verifies that the pilots can operate the aircraft safely in these challenging conditions but also confirms their familiarity with the associated procedures and any potential emergency situations that may arise. Overall, this criterion emphasizes safety and operational competence in minimizing risks during low visibility landings.

The other options do not encapsulate the required operational experience and competence needed for the removal of Category II limitations. For instance, merely training all pilots or conducting maintenance checks does not prove a pilot's capability to handle various complexities during an actual Category II approach and landing, which the specific completion of those approaches directly assesses.