TM 1-1510-225-10 3D-1 CHAPTER 3D AVIONICS GLOBAL POSITIONING SYSTEM KLN 90B T3  F3 3D-1.  GENERAL. a.   Applicability.        The    KLN-90B     Navigation System  is  only  applicable  to  the  C-12T3  and  C-12F3 aircraft.  The C-12R aircraft utilize the GNS-XLS Flight Management    System    to    access    GPS    navi gation.   C-12R crewmembers may remove this chapter. In  the  near  future  the  KLN-90B will be removed from  the  C-12T3   an   C-12F3  aircraft  and  this  entire chapter will be removed from the operator's manual. b.  Description.  The Global Positioning System (GPS) is a satellite based radio navigation system that utilizes     precise     range     measurements     from     GPS satellites to determine precise position anywhere in the world.    The  KLN  90B  provides  en  route  navigation information  and  non-precision  (except  localizer,  LDA, and SDF) instrument approach navigation. c.   Components.  (1)   KLN    90B    Panel.        Located    above    the weather  radar  on  the  instrument  panel,  it  contains  the GPS    sensor,    the    navigational    computer,    a    CRT display, and all controls required to operate the unit.  It also houses the database cartridge that plugs directly into the back of the unit.  Refer to Figure 3D-1. (2)   External Annunciators/Switches.  A panel located  just  to  the  right  of  the  altitude  select  on  the instrument  panel  contains  switches  to  select   OBS  or LEG  during  en  route  navigation  and  a  switch  to  arm the unit during approach.  It also has annunciators to indicate  when  a  message  is  active,  when  waypoint sequencing    is    about    to    occur,    and    when    altitude alerting   is   occurring.      The   annunciator   panel   also contains  a  jack  to  load  the  database  from  a  laptop computer.  Refer to Figure 3D-2. (3)   Antenna.    A  GPS  antenna  is  located  on the top of the fuselage at approximately STA 220. d.  Power.      Vdc   to   the   KLN   90B   is   provided through   a  5 -ampere   circuit   breaker   on   the   copilot’s sidewall circuit breaker panel labeled FMS No. 2. 3D-2.  DATABASE. a.   Database.    The  databases  for  the  KLN 90B have  a  primary  and  a  secondary  coverage  area.    All databases contain complete information for all worldwide VOR's, NDB's, and Minimum Safe Altitudes (MSA's).  For its  primary  area,  the  database  contains public  use  and  military  airports  that  have  any  runway at  least  1000  feet  in  length.    For  its  secondary  area, the   database   also   contains   airports   having   a   hard surface  runway  at  least  3000  feet  in  length.    Airport communication   frequencies   and   runway   information are   provided   only   for   airports   in   the   primary   area.   Intersections, air route traffic control center data, flight service  station  frequencies,  and  special  use  airspace are  also  provided  only  for  the  primary  area.   Refer to Figure 3D-3. 1.  Left CRSR 2.  Right CRSR 3.  Power/BRT Knob 4.  Right Inner and Outer Concentric Knobs 5.  ENT Button 6.  CLR Button 7.  Direct to Button 8.  ALT Button 9.  MSG Button 10.   Left Inner and Outer Concentric Knobs Figure 3D-1.  KLN 90B Controls