What action should be taken if the Horizontal Stab anti-ice failure light does not go out?

If the Horizontal Stab anti-ice failure light does not go out, the appropriate action is to perform a maintenance check. This is crucial because the persistent illumination of the anti-ice failure light indicates that there is a potential malfunction in the anti-ice system. Investigating the issue through a maintenance check allows for a thorough assessment of the system's functionality. This step is essential to ensure safety and verify that necessary repairs are made prior to further operations.

Continuing the test without addressing the illumination of the failure light could lead to potentially hazardous conditions, as the anti-ice system is critical for the safety and performance of the aircraft. Similarly, notifying ground control may be part of the protocol, but it does not resolve the issue directly, nor does pulling the circuit breaker provide a comprehensive solution; it might disable the system without solving the underlying problem. Therefore, executing a maintenance check is the most appropriate and prudent course of action in this situation.