Chapter 2: Airspace Classification, Operating Requirements, and Flight Restrictions 1. If the restricted area is not active and has been released to the FAA, the ATC facility allows  the aircraft to operate in the restricted airspace without issuing specific clearance for it to do  so. 2. If the restricted area is active and has not been released to the FAA, the ATC facility issues a  clearance that ensures the aircraft avoids the restricted airspace. Restricted areas are charted with an “R” followed by a number (e.g., R-4401) and are depicted on  the en route chart appropriate for use at the altitude or flight level (FL) being flown.  [Figure 10-1]  Restricted area information can be obtained on the back of the chart. Warning areas are similar in nature to  restricted areas; however, the United  States government does not have sole  jurisdiction over the airspace. A warning  area is airspace of defined dimensions,  extending from 3 NM outward from the  coast of the United States, containing  activity that may be hazardous to nonparticipating aircraft. The purpose of  such areas is to warn nonparticipating  pilots of the potential danger. A warning  area may be located over domestic or  international waters or both. The airspace  is designated with a “W” followed by a  number (e.g., W-237).  [Figure 2-4] MOAs consist of airspace with  defined vertical and lateral limits established for the purpose of separating certain  military training activities from  IFR traffic. Whenever an MOA  is being used, nonparticipating  IFR traffic may be cleared through an MOA if IFR separation can be provided by  ATC. Otherwise, ATC reroutes  or restricts nonparticipating IFR  traffic. MOAs are depicted on  sectional, VFR terminal area,  and en route low altitude charts and are not numbered  (e.g., “Camden Ridge MOA”).  [Figure 2-5]  However, the MOA  Figure 2-4.  Requirements for airspace operations. Figure 2-5.  Camden Ridge MOA is an example of a military operations area. Military Operation Areas (MOAs)  Warning Areas Remote Pilot – Small Unmanned Aircraft Systems Study Guide  8 