TM 1-1510-218-10 3-50 This  message  provides  a  reminder  that  to  fly  a course reversal, the OBS mode needs to be selected.   If  the  aircraft  is  approaching  the  IAF  from  an  area where  there  is  no  need  to  perform  a  course  reversal, ignore  the  message.    A  NoPT  arrival  sector  is  not stored in the database, so it is not possible for the KLN 90B to know that the course reversal is not required.   Therefore, the KLN 90B will always give the message whenever   a   waypoint   could   be   used   for   a   course reversal.    If  the  aircraft  is  approaching  from  a  NoPT arrival sector, remain in the LEG mode.  The KLN 90B will  properly  sequence  to  the  FAF  to  MAP  leg  and transition to the approach mode when 2 nm from the IAF/FAF. If  approaching  from  a  direction  that  requires  a course   reversal,   the   OBS   mode   will   need   to   be selected.      If   the   OBS   mode   is   not   selected   before reaching  the  IAF/FAF,  the  KLN  90B  will  automatically sequence  to  the  missed  approach  point.    This  is  not desirable if a course reversal is to be done. NOTE The KLN 90B will only provide the reminder to   select   OBS   if   the   IAF   is   the   active waypoint. 4.   If  a  course  reversal  is  required,  perform the   appropriate   procedure   and   set   the inbound course on the HSI upon reaching the IAF.  At this point, the KLN 90B works very similar to a conventional VOR/DME. 5.   Once  established  on  the  inbound  course, switch back to the LEG mode.  When LEG mode is selected, the FAF is automatically made  the  active  waypoint  when  the  IAF and the FAF are the same waypoint. NOTE It  is  mandatory  that  the  unit be in the LEG mode with the FAF as the active waypoint before   crossing   the   FAF   to   activate   the approach   active   mode   and   change   to   ± 0.3 nm  scale  factor.    The  CDI  scale  factor changes from ± 1.0 nm to ± 0.3 nm over the 2  miles  to  the  FAF.    Delaying  the   switch from  OBS  to  LEG  mode  compresses  the scale  factor  change.    This  will  make  the transition  more  abrupt.    If  the  switch  from OBS to LEG is delayed too long, it will not be  possible  for  the  KLN  90B  to  change  to the approach active mode. (1)   When  the  aircraft  is  2  nm  from  the  FAF, the    KLN    90B    will    verify    that    proper    integrity    is available.    If  integrity  monitoring  is  available  for  the approach,  the  KLN  90B  will  change  to  the  approach active mode.  This will be annunciated on the external approach  status  annunciator  as  well  as  on  the  KLN 90B.    The  CDI  scale  factor  will  also  start  to  change from ± 1.0 nm to ± 0.3 nm. (2)   Upon reaching the FAF, the KLN 90B will automatically sequence to the MAP. (3)   A  step  down  fix  may  not  be  included  in the   list   if   waypoints   are   provided  in  the  database.   Identify  this  point  by  using  the  along  track  distances given in the profile view of the approach plate.  In the leg  mode,  the  distance  given  by  the  KLN  90B  is  the distance to the next point (in this case, the MAP), not the distance from the last point (the FAF). (4)   The    KLN    90B    will    provide    waypoint alerting as the missed approach point is approached.   This is shown on the Super NAV 5 page as a flashing active   waypoint   identifier,   as   well   as   the   external flashing waypoint annunciator.  If the auto scale factor was  chosen  for  the  Super  NAV  5  page,  the  airport diagram will be visible when the aircraft is within 5 nm of the airport.  More detail is shown as the aircraft gets to within 1 nm of the airport. (5)   If a missed approach is required, the KLN 90B  will  not  automatically  sequence  past  the  missed approach   point.      To   perform   the   published   missed approach procedure, press the   D    button to bring up the  Direct  To  page.    The  default  waypoint  will  be  the first    waypoint    of    the    published    missed    approach procedure.  Confirm this waypoint as the   DIRECT  TO  waypoint and press the ENT button. NOTE If ATC instructions for the missed approach  are  different  from  the  published procedure, it is always possible to select a different direct to waypoint than the default DIRECT TO waypoint. (6)   Prior  to  reaching  the  first  point,  if  holding is  required,  select  the  OBS  mode  to  stop  waypoint sequencing   and   define   the   inbound   course   for   the holding  pattern  by  setting  the  proper  course  on  the HSI.      If   the   OBS   mode   is   not   selected  before  the aircraft  is  within  4  nm  of  the  holding  point,  the  KLN 90B presents a message as a reminder to select the OBS mode.