TM 1-1510-225-10 3D-49 h.  Radar Vectors.  1.   Select  the  approach  and  enter  it  into  the flight plan. 2.   When ATC initiates radar vectors, change the  active  waypoint  to  the  FAF  and  select OBS.      The   order   of   these   steps   is   not important.  It is just as effective to change to  OBS  mode  and  then  change  the  active waypoint. 3.   Change the selected course on the EHSI to the final approach course.  It is possible to  maintain  the  aircraft  orientation  on  the Super    NAV    5    page.        Refer    to    Figure 3D-68. 4.   Once  established  on  the  inbound  course, change back to the LEG mode to allow for proper  approach  operation  and  automatic leg   sequencing.      For   best   performance, the change back to LEG mode should be made before the  aircraft  is  2  nm  from  the FAF. Figure 3D-68.  Radar Vectors NOTE It is mandatory that the unit is 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. 5.   The   rest   of   the   approach   will   be   flown using the same steps presented previously. i.    On Airport Navaid Approach. 1.   Select  the  approach  and  enter  it  into  the flight plan. 2.   When     the     distance     from     the     present position to the destination airport reaches 30 nm, the KLN 90B will arm the approach mode.  The CDI scale factor will transition to  ±  1.0  nm  and  the  KLN  90B  will  provide more sensitive integrity monitoring.  Press the  altitude  button  to  update  the  altimeter setting. 3.   When the aircraft is 4 nm from the IAF, the KLN 90B will provide a reminder to select the    OBS    mode.        The    OBS    mode    is required   for   the   procedure   turn.      After passing    the    IAF,    select    the    outbound course on the EHSI. 4.   The  aircraft  is  now  headed  outbound  for the procedure turn.  As soon as practical, change the active waypoint to the FAF. a.   Pull  out  the  right  inner  knob  with  the Super  NAV  5  page  displayed.    Scan the  waypoints  until  the  FAF,  FFxx-f, is displayed  in  the  window  and  press  the   D      button.      Refer   to   Figure   3D-69.   Since the course to the FAF is already defined   (in   the   OBS   mode   with   the EHSI    set    to    the    outbound    course), press the   D   button a second time to activate  this  waypoint  instead  of  going directly to it. 5.   With the OBS mode selected and the FAF as the active waypoint, it is possible to fly the procedure turn. Allow enough distance   past   the   FAF   to   complete   the procedure   turn   and   still   be   2   nm   away from  reaching  the  FAF.    After  completing the  heading  portion  of  the  procedure  turn, change the selected course to the inbound course on the EHSI. 1.1 NM BQM-i ARM-068 107 KT .01NM OBS068^o TK071^o 2 BQM FF24 FF24-f Figure 3D-69.  Activate the FAF