Final answer:
The typical outer radius limits of Class C airspace extend up to 10 nautical miles, with an additional outer area for traffic advisory services extending up to 20 nautical miles.
Step-by-step explanation:
The question you've asked pertains to the limits of Class C airspace. A typical Class C airspace is designed to support airports that have an operational control tower, are serviced by a radar approach control, and have a certain number of IFR (Instrument Flight Rules) operations or passenger enplanements. The airspace is generally shaped like an upside-down wedding cake with two layers. The inner core extends from the surface up to 4,000 feet above the airport elevation, and has a radius of 5 nautical miles. The upper shelf of airspace extends from 1,200 feet up to 4,000 feet above the airport surface and has a radius of 10 nautical miles. Beyond that, there is an outer area of 20 nautical miles radius that is not technically part of the Class C airspace but where participating aircraft can receive air traffic control services. So, the correct answer to your question is that the typical outer radius limits of Class C airspace extends up to 10 nautical miles for the shelf area, and if considering the outer area where traffic advisory services are available, it goes up to 20 nautical miles.