What is the normal vertical limit of Class D airspace?

The normal vertical limit of Class D airspace extends up to 2,500 feet above the surface, but it is important to note that this airspace typically starts at the surface and can go up to an upper limit that is determined by the specific airspace. While this upper limit can vary, it is not inherently defined as 12,500 feet ASL for Class D.

In actual practice, Class D airspace often extends to the ceiling of the associated controlled airspace, which may reach up to 10,000 feet or sometimes higher in certain circumstances depending on air traffic and geographic considerations. Therefore, the upper limit can vary rather than being fixed to 12,500 feet ASL, which is a characteristic of Class E airspace rather than Class D.

None of the provided choices accurately reflect the typical characteristics of Class D airspace limits, which are primarily defined by regulatory charts and specific air traffic control procedures rather than fixed altitudes. This is crucial for pilots to understand in order to navigate through or in proximity to controlled airspace correctly.