Index   90 -- Page 91 -- 92

12/10/15                                                                                                      AIM




                       FIG 1-2-4                                                  FIG 1-2-6
                Direct to Fix Leg Type                                    Radius to Fix Leg Type




                                                                     (5) Heading. A Heading leg may be
          (3) Course to Fix. A Course to Fix (CF)
                                                           defined as, but not limited to, a Heading to Altitude
leg is a path that terminates at a fix with a specified
                                                           (VA), Heading to DME range (VD), and Heading to
course at that fix. Narrative: "on course 150 to
                                                           Manual Termination, i.e., Vector (VM). Narra-
ALPHA WP." See FIG 1-2-5.
                                                           tive: "climb heading 350 to 1500", "heading 265, at
                                                           9 DME west of PXR VORTAC, right turn heading

                       FIG 1-2-5                           360", "fly heading 090, expect radar vectors to
               Course to Fix Leg Type                      DRYHT INT."
                                                                  (c) Navigation Issues. Pilots should be
                                                           aware of their navigation system inputs, alerts, and
                                                           annunciations in order to make better-informed
                                                           decisions. In addition, the availability and suitability
                                                           of particular sensors/systems should be considered.
                                                                    (1) GPS/WAAS. Operators using TSO-
                                                           C129(), TSO-C196(), TSO-C145() or TSO-C146()
                                                           systems should ensure departure and arrival airports
                                                           are entered to ensure proper RAIM availability and
                                                           CDI sensitivity.
                                                                   (2) DME/DME. Operators should be
                                                           aware that DME/DME position updating is depen-
                                                           dent on navigation system logic and DME facility
                                                           proximity, availability, geometry, and signal mask-
                                                           ing.
                                                                   (3) VOR/DME. Unique VOR character-
                                                           istics may result in less accurate values from
                                                           VOR/DME position updating than from GPS or
                                                           DME/DME position updating.
                                                                    (4) Inertial Navigation. Inertial reference
          (4) Radius to Fix. A Radius to Fix (RF)          units and inertial navigation systems are often
leg is defined as a constant radius circular path around   coupled with other types of navigation inputs,
a defined turn center that terminates at a fix. See        e.g., DME/DME or GPS, to improve overall
FIG 1-2-6.                                                 navigation system performance.


Performance-Based Navigation (PBN) and Area Navigation (RNAV)                                               1-2-3