If your destination airport has a NOTAM stating circuit height is 1,500 feet ASL and airport elevation is 400 feet ASL, what should your circuit altitude be under overcast conditions?

The key to understanding the appropriate circuit altitude under overcast conditions lies in recognizing the relationship between the cloud base and the altitude of your circuit. Given that the NOTAM specifies the circuit height as 1,500 feet ASL, and considering the airport elevation of 400 feet ASL, it’s imperative to maintain a safe altitude above the cloud base to avoid the potential hazards of inadvertently entering the clouds.

In this scenario, the choice to set the circuit altitude at 500 feet below the cloud base is based on the requirement to remain clear of any cloud formation while also being at a safe altitude for circuit operations. The NOTAM indicates that the circuit altitude should be at 1,500 feet ASL; however, if the weather conditions indicate an overcast, the key is to interpret "below the cloud base" accurately.

For a cloud base at 1,500 feet ASL, being 500 feet below means you would be at 1,000 feet ASL, which also accommodates a safety buffer when flying near clouds. In summary, maintaining a circuit altitude of 1,000 feet above the airport elevation ensures safety while complying with the NOTAM directives under the stipulated weather conditions. This altitude effectively keeps you clear of the clouds