CPAverify minimizes the need to check the website of each State Board of Accountancy individually to determine a CPA's license status. CPAverify, with support from participating State Boards of Accountancy, allows consumers the opportunity to check the status of multiple licenses a professional holds at one website.
Generally, if the airspace is not Class A, B, C, or D, and is controlled airspace, then it is Class E airspace. Class E airspace extends upward from either the surface or a designated altitude to the overlying or adjacent controlled airspace.
In the USA the term control zone is no longer used and has been replaced by airspace class D. Typically it extends 5 miles in diameter with a height of 2500 ft AGL (above ground level) around small commercial airports.