TM 1-1510-225-10 3D-72 PVW00       NEW FW  –  ABQ   CTR PVW         001°         28.7 NM N     34° 33.21' W    101° 40.01' ENT    CTR+2 Figure 3D-109.  Center 2 Page (2)   Inserting    Center    Waypoint    Into    Flight Plan.  Insert the enter waypoints into the desired flight plan by returning to the CTR 1 page on the right side and pressing the  ENT  button.    The  Center  waypoints are  inserted  into  the  flight  plan  in  the  correct  order.   Refer to Figure 3D-110. USE? INVRT?   1:KLBB   2:PVW00   3:BGD00   4:GCK00   5:KMCK FPL 3 CTR 1 E N R   -   L E G CTR WPT INSERTION COMPLETE Figure 3D-110.  Insert Center Waypoints (a)   If     inserting     the     waypoints     would cause   the   number   of   waypoints   to   exceed   30,   no Center  waypoints  are  displayed  and  the  CTR  1  page will display, NOT ENOUGH ROOM IN FPL. (b)   After    the    Center    waypoints    have been inserted into a flight plan, they may be viewed by returning  to  the  CTR  2  page.    As  long  as  the  same flight  plan  is  displayed  on  the  left  side  of  the  screen, the Center waypoints may be viewed by displaying the CTR 2 page(s).  The CTR 1 and 2 pages return to their original  format  any  time  the  specific  flight  plan  is  no longer  displayed  on  the  left  side.    To  view  the  Center waypoints   again,   return   to   the   specific   flight   plan, select the CTR 2 page, and press the  ENT button. (c)   Center  waypoints  are  stored  as  part of the 250 user-defined waypoints and are considered supplemental waypoints.  When Center waypoints are viewed  on  the  SUP  page  or  on  the  active  waypoint (ACT)  page,  they  appear  in  the  normal  supplemental waypoint  format.    Center  waypoints  that  are  part  of  a flight   plan   show   up   on   the   OTH   3   page.      Center waypoints that  are  no  longer  part  of  a  flight  plan  are deleted  from  the  list  of  user-defined  waypoints  when the KLN 90B is turned off. (d)   Once   center   waypoints   have   been inserted  into  a  flight  plan,  they  are  treated  like  any other   waypoints   in   the   flight   plan.      If   a   flight  plan containing  center  waypoints  is  modified  in  any  way, new center waypoints may be computed.  The original center  waypoints  are  now  part  of  the  flight  plan  and new  center  waypoints  are  computed  by  treating  the original   center   waypoints   the   same   as   any   other waypoints  in  the  flight  plan.    If  the  interior  of  a  flight plan containing center waypoints is modified, it may be desirable to manually delete obsolete center waypoints from    the    flight    plan    before    computing    new    ones; however,  if  the  flight  plan  is  modified  by  adding  new waypoints to the end of the flight plan, this may not be necessary. 3D-28.  THE STATUS PAGES. There   are   four   status   pages.   The   STA   1   and STA 2 pages display information pertaining specifically to the GPS receiver, while the STA 3 and STA 4 pages display  supplementary  information  pertaining  to  the KLN 90B. The  STA  1  and  STA  2  pages  may  be  viewed  at any time to determine the status of the GPS receiver and  the  GPS  satellites  being  received.    This  includes which satellites are being tracked, the satellites health, the signal to noise ratio for each of the satellites, the elevation  of  each  satellite  above  the  horizon,  and  the estimated position error. The GPS receiver in the KLN 90B is capable of using  signals  from  up  to  eight  satellites  to  determine position.  A valid position may be determined using as few  as  four  satellites  alone  or  three  satellites  with  an altitude input.  However, four satellites alone or three satellites   with   an   altitude   input   do   not   necessarily ensure that navigation can take place.    The  satellites must  be  positioned  relative  to  the  aircraft  such  that sufficient  geometry  exists  to  determine  an  accurate position.        The    satellite    constellation    geometry    is continually   changing   as   each   satellite   rises,   travels across   the   sky,   and   eventually  sets  relative  to  the aircraft’s   position.      The   GPS   satellites   are   not   in geosynchronous orbits positioned over the same spot on  the  earth  at  all  times.    Rather,  the  GPS  satellites are in orbits that allow them to circle the earth about two times each day. a.   STA 1 Page.  There will be two STA 1 pages if  more  than  four  satellites  are  being  received.     The GPS state is indicated on line 1.  Refer to Table 3D-17 for GPS status codes and their meanings.