TM 1-1510-225-10 3D-16 (3)   The  Super  NAV  1  Page.  When the NAV 1  page  is  selected  on  both  the  left  and  right  sides  at the  same  time,  the  Super  NAV  1  page  is  displayed.   The  Super  NAV  1  page   contains  exactly  the  same information  as  the  standard  NAV  1  page  but  spreads the  data  across  the  entire  screen  making  it  easier  to view. b.  NAV  2  Page.   The  NAV  2  page  displays  the aircraft’s  present  position  in  two  formats.    The  first format  is  in  terms  of  the  distance  and  radial  from  a nearby  VOR.    The  second  format  is  in  latitude  and longitude. c.   NAV 3 Page.  Refer to Figure 3D-11. (1)   Desired  Track  (DTK).    The  great  circle course   between   two   waypoints.      Any   CDI   or   EHSI driven by the KLN 90B, including the CDI displayed on the NAV 1 page is referenced to this desired track. NOTE If  the  KLN  90B  is  in  the  OBS  mode,  the selected course (OBS) is displayed instead of the desired track.      D OSH DTK    303^o TK     302^o FLY L 2.7NM MSA  3300FT ESA  5500FT NAV 3 Figure 3D-11.  NAV 3 Page (2)   Actual Track (TK).  The aircraft’s present track over the ground. (3)   Cross  Track  Error  Correction.    This  is  a text means of indicating how far and which direction to get  back  on  course.    It  is  consistent  with  the  vertical deviation bar displayed on the NAV 1 page. (4)   Minimum Safe Altitude (MSA).  The MSA displayed  is  the  altitude  defined by Jeppesen as Grid Minimum    Off-Route    Altitude    (Grid    MORA).        This altitude is derived by Jeppesen for sectors that are 1° of  latitude  by  1°  of  longitude  in  size.    One  degree  of latitude is 60 nm.  One degree of longitude is 60 nm at the equator and  progressively less than 60 nm as one travels    away    from    the    equator.        One    degree    of longitude is approximately 50 nm at the southern most parts  of  the  U.S.  and  is  approximately  40  nm  at  the northern  most  parts  of  the  U.S.    The  MSA  altitude information    is    contained    in    the    database    and    is updated when the database cartridge is updated. The   MSA   provides   reference   point   clearance within  these  1°  latitude  by  1°  longitude  sectors.    A reference point is defined as a natural (peak, knoll, hill, etc.)  or  man-made  (tower,  stack,  tank,  building,  etc.) object.    Grid  MORA  values  clear  all  reference  points by   1000   feet   in   areas   where   the   highest   reference points  are  5000  feet  MSL  or  lower.    MORA  values clear  all  reference  points  by  2000  feet  in  areas  where the highest reference points are above 5000 feet MSL.   The  KLN  90B  displays  dashes  for  areas  outside  the database  coverage  area  or  for  areas  where  the  Grid MORA is not defined. The MSA and ESA altitudes are advisory in nature   only.      They   should   not   be   relied upon  as  the  sole  source  of  obstacle  and terrain clearance. Refer to current aeronautical charts for appropriate minimum clearance altitudes.  (5)   Minimum  En  Route  Safe  Altitude  (ESA).   When the KLN 90B is in the LEG mode, the ESA is the highest  MSA  from  the  present  position  to  the  active waypoint,  to  the  destination  waypoint  via  the  active flight  plan.    When  the  KLN  90B  is  in  the  OBS  mode, the ESA is the highest MSA from the present position to the active waypoint.  Refer to Figure 3D-12.   Figure 3D-12.  Minimum En Route Safe Altitude d.  NAV  4  Page.    The  NAV  4  page  is  used  for altitude  alerting  and  for  advisory  vertical  navigation.     Refer to Figure 3D-13. WARNING