Preprogrammed holding pattern (preprogrammed hold). A hold that is published as a part of an instrument procedure  (e.g., approach, missed approach) and has been loaded into  the FMS/RNAV. Some FMS/RNAV units automatically  enter and fly the holding procedure when it is encountered.  Others must be flown around the depicted holding pattern,  usually by changing the heading (bug). Some units require  switching to the nonsequencing or OBS mode so the active  waypoint remains set to the designated holding fix. Resolution advisory (RA).  A warning issued by the Traffic  Collision Avoidance System (TCAS) indicating an immediate  threat of collision with another aircraft. This warning takes  the form of a command to perform a vertical avoidance  maneuver (e.g., “Climb! Climb!”) These commands are  products of TCAS II equipment. These commands take  precedence over ATC instructions, but must be reported to  ATC immediately upon receipt and execution. Risk homeostasis.  A term coined by psychologist Gerald J.  S. Wilde, a tendency for humans to seek target levels of risk. RNAV.  See Area Navigation. Preprogrammed course reversal. A course reversal  (commonly called a “procedure turn”) that appears as part  of an instrument approach procedure that has been loaded  into the FMS/RNAV. Many FMS/RNAV units automatically  attempt to perform the course reversal procedure when it is  encountered. Others require the pilot to navigate the depicted  procedural track manually or by using the heading mode to  fly the depicted track. RNAV (GPS) approach.  An approach procedure based on  GPS signals for guidance. Route discontinuity.  A point of uncertainty in a route that  has been programmed into an FMS/RNAV. Most systems  display this message when there is no routing to connect the  last waypoint to the next point, or there is a missing next  point. FMS/RNAV units will not plan to go direct unless  certain programming parameters are met. Primary flight display (PFD).  An electronic flight display  that presents the primary flight instruments, navigation  instruments, and other information about the status of the  flight in one integrated presentation. Primary‑secondary task  inversion. Situation in which the pilot ceases to monitor the  situation directly and simply listens for system alerts. Sequencing mode.  The FMS/RNAV mode that automatically  sequences along the waypoints in the programmed route. The  sequencing mode alerts the pilot to upcoming waypoints, and  offers guidance to each successive waypoint in the route. Radar attenuation.  The absorption or reflection of radar  signals by a weather cell, preventing that radar from detecting  any additional cells that might lie behind the first cell. RA.  See resolution advisory. Stand-alone approach.  An instrument approach that relies  solely on the use of RNAV equipment. If flown with GPS/ WAAS enabled certified equipment in accordance with  TSO‑C145A or TSO‑146A installed in accordance with  the provisions of AC 20‑130A or 138A, no conventional  navigation equipment alternate approach (VOR/ILS)  requirements are necessary, as when flying with TSO‑C129  certified equipment. RAIM. See receiver autonomous integrity monitoring.  Receiver autonomous integrity monitoring. The self‑ monitoring function performed by a TSO‑129 certified GPS  receivers to ensure that adequate GPS signals are being  received at all times. The GPS will alert the pilot whenever  the integrity monitoring determines that the GPS signals do  not meet the criteria for safe navigation use. Subpage. An additional page of information about a  particular topic that can be displayed on an FMS/RNAV.  Many pages require the use of several subpages to show all  information pertaining to any one topic. Receiver autonomous integrity monitoring. The self‑ monitoring function performed by a TSO‑129 certified  GPS receiver to ensure that adequate GPS signals are being  received at all times. The GPS alerts the pilot whenever the  integrity monitoring determines that the GPS signals do not  meet the criteria for safe navigation use. SUSP.  See suspend mode. G-5