How high does Class E airspace typically extend up to?

Class E airspace can extend from either the surface or a specified altitude, commonly starting at 1,200 feet AGL and extending up to 18,000 feet MSL. In many regions, particularly under the Federal Aviation Regulations (FAR), this class of airspace is structured so that it does not interfere with the operation of the lower classes like Class G.

The range of Class E airspace varies based on the specific regional requirements and airspace configuration. While certain airspace areas may have Class E extending up to lower altitudes such as 10,000 feet, the more universal understanding is that it can extend up to 18,000 feet. Therefore, the provided altitude in the multiple-choice question is indicative of the upper limit for an expansive segment of Class E airspace, which also aligns with the transition to the higher classes of airspace such as Class A, which starts at 18,000 feet.

This differentiation is essential because it delineates how pilots navigate within the various classes of airspace while ensuring compliance with the specific regulations and requirements applicable to each class.