What is the windshield heat usage when above 30?

The windshield heat usage when above 30 degrees Fahrenheit is appropriately set to "Off." At temperatures above freezing, specifically above 30 degrees Fahrenheit, the likelihood of ice formation on the windshield significantly decreases. Therefore, using the windshield heat in these conditions is unnecessary and can lead to increased energy consumption and potential wear on the heating components.

Using the heat may also create haze that can obstruct visibility, which is particularly important when operating a vehicle. Thus, keeping the windshield heat off is a practical and efficient choice in warmer temperatures where icing conditions are not a concern. This understanding helps in making informed decisions about aircraft and vehicle operations, ensuring efficiency and safety.