Which statement about "shallow fog" during an approach is false?

The concept behind instrument flight rules (IFR) is to maintain reference to instruments throughout the flight, especially during approaches and landings. However, stating that instrument flight references should be maintained until landing is misleading in the context of shallow fog.

In shallow fog conditions, while pilots are indeed trained to rely on their instruments during the final phases of the approach, they must also be prepared for visual references. When the runway environment is in sight, a pilot can transition from instrument references to visual references to execute a safe landing. Therefore, the statement suggesting that instrument flight references should be maintained until landing can be seen as false because it implies a lack of transition to visual reference, which is critical once you have the runway in sight.

Other statements correctly reflect the nature of shallow fog. Visibility is indeed significantly restricted by shallow fog, meaning that pilots must be highly vigilant during these conditions. It is also critical that the runway environment be visually confirmed to proceed safely – this requirement underscores the relevance of visual references during an approach. Lastly, maintaining a crosscheck until reaching the runway is a fundamental practice to ensure that all systems are working properly and that the approach remains stable, adapting to any conditions encountered, including shallow fog.