TM 1-1510-225-10 3B-62 Table 3B-16.  Navigation Configuration Page Access and Functions NO. DESCRIPTION/FUNCTION 1 Select Index 1 page. 2 Access Nav Config 1 page. 3 Indication of designated pilot selection. 4 Flight Plan Guidance-Blank Limit. 5 Flight  instrument  scaling  mode  selection: OCEANIC,    EN    ROUTE,    TERMINAL,    or APPROACH. 6 Scroll vertically to access more configuration pages. 7 Entered   Speed   deviation   alert   threshold (knots). 8 Entered ground speed default for calculations while on the ground. 9 Entered   waypoint   alert    time   in   seconds prior to waypoint arrival or leg switch. 10 Entered cross track deviation alert threshold (nautical miles). When  a  waypoint  alert  time  is  entered,  the  FMS will  provide  an  external  waypoint  alert  advisory  and then the FMS will sequence  to the next waypoint with the alert threshold.  This waypoint alert threshold only affects  external  advisories  on  capsule  lights  or  flight instruments  to  give  the  pilot  a  heads-up of impending transitions   while   in   OCEANIC   or   EN   ROUTE   flight modes.  When in  TERMINAL  or  APPROACH  modes, the    FMS    and    external    advisories    will    always    be generated 10 seconds prior to waypoint sequencing. (f)   Ground   Calculation.      When   on   the ground, the FMS provides the pilot the ability to review flight    profiles    and    system    calculations.        On    the Navigation  Configuration  2  page  while  on  the  ground, a    groundspeed    entry    is    provided    for    the    pilot    to forecast  anticipated  performance  in  flight  and  provide expected flight times enroute to each destination in the flight plan. e.   Active Flight Plan Waypoints and Courses.  (1)   Flight  Plan  Overview.     The  active  flight plan is a list of up to 60 waypoints, stored in the order they  are  to  be  flown.    The  flight  plan  is  maintained through addition, modification, or deletion of waypoints.    When  a  waypoint  is  passed, it is retained in the flight plan history list, where the last 39 passed waypoints are maintained in order.  History waypoints are    identified    in    the    flight    plan    with    a    #    symbol following  the  waypoint  number  and  may  be  viewed  by scrolling  the  Flight  Plan   page  using  the   -   key.    The crew may delete history waypoints, using a  – entry, but may not enter waypoints into history. The    FMS-800     guidance     function     assists     in execution  of  the  flight  plan  by  determining  deviations from    the    desired    flight    plan    and    controlling    the sequencing     of     waypoints.          When     automatic     leg advance is selected via the Flight Plan page, waypoint switching is determined as a function of aircraft speed, wind, and magnitude of course change to provide turn anticipation.    A  waypoint  alert  is  generated  prior  to reaching the waypoint switching point for the next leg. (a)  Flight Plan Loading.  There are three ways to enter flight plan data: 1.   Through the active flight plan. 2.   The alternate flight plan. 3.   The data cartridge catalog. (b)  Data Cartridge.  The data cartridge is a   storage   device   containing   a   catalog   of   Alternate Flight Plans (AFP).  The cartridge can be modified at a Mission  Planning  Ground  Station  (MPGS)  which  can store  thousands  of  unique  flight  plans.    Up  to  40  of those flight plans at one time  can  be  transferred  from the MPGS to the Alternate Flight Plan Catalog in the data cartridge.  The pilot can then choose one of these AFP's  from  the  catalog  on  the  data  cartridge  to  load into the AFP in the CDU.  After loading the AFP, the pilot   can   make   any   changes   or   transfer   the   AFP directly to the active flight plan.  If desired, the pilot can also modify an AFP and save it back to the catalog in the cartridge.  Refer to Figure 3B -25 for a summary of the information flow. (2)   Flight     Plan     Active     Waypoint.          The waypoint  that  all  flight  instrument  and  CDU  guidance displays  are  referenced,  is  referred  to  as  the  active waypoint.        Pressing    the    FPLN    key    on    the    CDU accesses the Flight Plan page with the active waypoint displayed  as  the  TO  waypoint.    This  is  signified by ¯¯ pointing to the active waypoint. Associated    with    the    active    waypoint    are    the following    parameters,    which    are    displayed    on    the Flight Plan page. 1.   Current desired inbound course measured at the waypoint, not current desired track at aircraft position. 2.   Source  of  inbound  course.    The  three sources are: Computed (¯ ¯), manually entered (¯  man ¯ ), or direct- to (¯  dir  ¯ ).