How often are the steel carabiners stamped "SMC" or "SMC USA" checked?

The correct answer is based on the importance of maintaining safety standards in equipment used for aerial activities. Steel carabiners stamped "SMC" or "SMC USA" should be checked every 2 hours or before the first flight after a new aerial controller change to ensure they are in proper working condition. This frequent inspection is critical because carabiners are essential components that bear significant load and stress during operations.

Checking them at this interval allows controllers to identify any signs of wear, damage, or malfunction that could compromise safety before they affect any flights. The timing, especially after a new aerial controller change, is crucial because different operators may have different handling habits or practices that could affect the carabiners' integrity. Implementing this safety measure ensures that all equipment remains reliable and secure, thus prioritizing the safety of both the participants and the operators involved.