At what point must a pilot initiate a missed approach during an ILS approach?

The correct point for a pilot to initiate a missed approach during an Instrument Landing System (ILS) approach is at the Decision Height (DH) if the runway visual references are not distinctively visible. The DH is a predetermined altitude or height in an ILS approach at which the pilot must make the decision to either continue the approach to landing or execute a missed approach. If the required visual references, such as the runway or its markings, are not visible at DH, the pilot must promptly initiate the missed approach to ensure safety.

This procedure is critical for maintaining safety during low visibility conditions, as it helps prevent the aircraft from inadvertently continuing down the approach towards the runway without the necessary visual cues. Initiating a missed approach at DH is a defined protocol in instrument flight rules to ensure that aircraft do not descend below this altitude without having adequate visual references to land.