TM 1-1510-218-10 3-70 5.   Turn  the  left  outer  knob  to  move  the cursor  to  the  first  BARO  position  and then enter the current altimeter setting using the left inner and  outer knobs.  If the altimeter setting was made on the CAL     1     page,     it     will     already     be displayed. 6.   Rotate the left outer knob to move the cursor  to  the  first  TEMP  position,  and then enter the outside air temperature (in   °C)   by   using   the   left   inner   and outer   knobs.      The   first   digit   of   the temperature  is  either  zero  (0)  if  the temperature  is  above  zero  or  a  minus (–)  if  the  temperature  is  below  zero.   For  maximum  accuracy,  the  total  air temperature  should  be  entered.    This is  the  temperature  of  the  air  including the effect of heating due to movement through  the  air.    Because  of  the  two types  of  temperature,  a  temperature entry  made  on  the  CAL  1  page  is  not transferred  to  the  CAL  2  page.    The TAS is now displayed as illustrated in Figure 3-97. 7.   Press the left  CRSR button to turn off the left cursor function. CAL 2     TAS CAS:  187KT ALT:24000FT BARO:29.92” TEMP: -32^o C TAS   265KT Figure 3-97.  CAL 2 Page (3)   The Calculator 3 Page.  The CAL 3 page is  used  to  calculate  the  wind  direction  and  speed.    In addition,  the  headwind  or  tailwind  component  of  the wind is displayed.  Refer to Figure 3-98. NOTE Wind calculations are only correct when an accurate  heading  and  true  airspeed  have been entered. NOTE If    the    KLN    90B    is    interfaced    with    the AETMS,   line   three   of   the   CAL   3   page   is blank.  Heading is automatically input and used in the wind calculation. If    the    KLN    90B    is    interfaced    with    the AETMS,  the  OTH  9  page  displays  present wind information directly. CAL 3    WIND TAS   261KT HDG    343^o HDWND  21KT WIND  042^o t        53KT Figure 3-98.  CAL 3 Page 1.   Select the CAL 3 page on the left side. 2.   Press the left  CRSR button to turn on the cursor function. 3.   Enter  the  TAS  by  using  the  left  inner and outer   knobs.    If  the  CAL  2  page was  previously  used  to  calculate  the TAS, it will already be displayed. 4.   Use  the  left  outer  knob  to  move  the cursor  to  the  first  HDG  position,  and then  enter  the  aircraft's  heading  using the  left  inner  and  outer  knobs.    The headwind (HDWND) or tailwind (TLWND)  and  the  wind  direction  and speed  are  now  displayed.    The  wind direction is relative to true North. 5.   Press the left  CRSR button to turn off the cursor function. (4)   The Calculator 4 Page.  The CAL 4 page is used to determine vertical navigation descent/ascent angles  to  use  on  the  Nav  4  page.    Refer  to  Figure 3-99.