TM 1-1510-218-10 3-8 (a)  The   KLN   90B   needs   to   have   the correct time, date, and position to be able to determine which satellites should be in view.  This information is stored in the battery-backed  memory  of  the  KLN  90B so it is not normally necessary to update it.  If the KLN 90B has the correct date, time, and position, the time to NAV ready will usually be 2 minutes or less.  If this information is not correct, the KLN 90B will start to look for  satellites  to  determine  the  position  of  the  aircraft.   This process can take as long as 12 minutes but will normally be around 6 minutes.  It is possible to update this   information   manually,   which   will   allow   the   KLN 90B  to  reach  a  NAV  ready  status  much faster.  If the date  and  time  are  correct,  or  acquisition  time  is  not important, proceed to step (8). (b)  If the date is incorrect, rotate the right outer  knob  counterclockwise  until  the  cursor  is  over the  date  field.    Rotate  the  right  inner  knob  until  the correct day of the month is displayed.  Then, rotate the right   outer   knob   one   step   clockwise   to   place   the flashing part of the cursor over the month field.  Rotate the   right   inner   knob   to   display   the   correct   month.   Rotate  the  right  outer  knob  one  step  clockwise again and use the right inner knob to select the first digit of the correct year.  Next, rotate the right outer knob one more step clockwise and then use the right inner knob to select the second digit of the year.  When the date is correct, press ENT. (c)  If it is necessary to reset the time, use the right outer knob to position the cursor over the time zone field.  Use the right inner knob to select one of 19 time zones.  UTC  - Coordinated Universal Time (Zulu) is always a safe choice.  Then turn the right outer knob one step counterclockwise to position the cursor over the  time  field.    Use  the  right  inner  knob  to  select  the correct hour.  Twenty-four hour time is used.  Now turn the right outer knob one step clockwise to position the flashing   part   of   the   cursor   over   the   first   minutes position.      Turn   the   right   inner   knob   to   select   the desired  value.    Turning  the  right  outer  knob  one  more step  clockwise  positions  the  flashing  cursor  over  the second minutes position and the right inner knob is not used to fi nalize the time selection.  When the correct time  has  been  entered,  press   ENT  to  start  the  clock running.  The KLN 90B system time will automatically be corrected very precisely once a satellite is received. (7)   Altimeter Setting. (a)  With the Army Engine Trend Monitoring   (AETM)   system   installed   and   interfaced with  the  appropriate  altimeter,  the  correct  barometric altimeter setting is input via the pilot's altimeter.  It will not be possible to access the BARO field on the Self- Test  page  or  the  Altitude  page.    If  there  is  no  colon after the BARO field, it cannot be accessed by the pilot with the controls on the KLN 90B. (b)  Turn the right outer knob clockwise to position   the   cursor   over   the   first   two   digits   of   the barometric altimeter setting if the cursor is not already there.  If the correct altimeter setting is displayed, skip to step (d). (c)  To enter the correct altimeter setting, rotate the right inner knob to select the first two digits.   Rotate   the   right   outer   knob   one   step   clockwise   to move the flashing cursor over  the third position.  Use the right inner knob to select the correct number.  Use the right outer knob and inner knobs to complete the altimeter setting and press ENT. (d)  With    the    correct    altimeter    setting entered,   the   altitude   displayed   on   line   4   should   be correct within 100 feet. (8)   Turn   the   right   outer   knob   clockwise   to position  the  cursor  over  APPROVE?  if  it  is  not  there already.    Press   ENT  to  approve  the  Self-Test page.   Five  beeps  should  be  heard  when  the  Self-Test page is approved to confirm altitude alert audio.  If the  GPS CRS  switch   is   in   the   OBS   position,   then   the   OBS warning page will be displayed and   GPS CRS switch should be pushed so that the LEG mode is selected. (9)   The database page will now be displayed with    the    cursor    over    ACKNOWLEDGE?.        Line    1 indicates the coverage area.  Line 3 will show the date the  database  expires.    The  KLN  90B  will  still  function with an out of data database. CAUTION The  accuracy  of  the  database  information is assured only if the database is current. Press  ENT  to  acknowledge  the  information  on the database page. The    NAV    2    Present    Position    page    is    now automatically  displayed  on  the  left  side  of  the  screen and  the  Waypoint  page  which  was  active  when  the KLN  90B  was  last  turned  off  will  be  displayed  on  the right   side.      Refer   to   Figure   3-5.      If   the   last   active waypoint   was   an   airport,   the   APT   4   page   (airport communications) will be displayed. When the NAV 2 page first appears, it is possible that  the  present  position  will  be  dashed.    It  can  take the   KLN   90B   several   minutes   to   acquire  the  GPS satellites   and   to   make   its   initial   calculation   of   its position.  When it reaches a NAV ready status and is able   to   navigate,   the   NAV   2   page   will   display   the