Figure 4-33. Procedure turn obstacle clearance.  for non-precision approaches) or MAP, whichever occurs  last within the final approach area. It is dependent upon  the pilot to maintain an appropriate flight path within  the boundaries of the final approach area and maintain  obstacle clearance.  There are numerous types of instrument approaches  available for use in the NAS including RNAV (GPS), ILS, MLS,  LOC, VOR, NDB, SDF, and radar approaches. Each approach  has separate and individual design criteria, equipment  requirements, and system capabilities.  10,212 - with additional procedures published every revision  cycle. While it had originally been the plan of the FAA to  begin decommissioning VORs, NDBs, and other ground- based NAVAIDs, the overall strategy has been changed to  incorporate a majority dependence on augmented satellite  navigation while maintaining a satisfactory backup system.  This backup system includes retaining all CAT II and III ILS  facilities and close to one-half of the existing VOR network.  Each approach is provided obstacle clearance based on the  FAA Order 8260.3 TERPS design criteria as appropriate for  the surrounding terrain, obstacles, and NAVAID availability.  Final approach obstacle clearance is different for every  type of approach but is guaranteed from the start of the  final approach segment to the runway (not below the MDA  To expedite traffic, ATC may clear pilots for a visual  approach in lieu of the published approach procedure if  4-55 Visual and Contact Approaches  Obstacle  Obstacle  Entry zone  Maneuvering zone  Procedure turn completion altitude  Altitude restricted until completing  departing turn fix outbound  6,000  6,900  7,700  1,000 feet  1,000 feet 