TM 1-1510-225-10 3A-94 (4)   Direct To VNAV Waypoint. This procedure allows the pilot to program a direct to on the vertical flight plan, while still flying the lateral waypoints on  the  active  flight  plan.    The  VNAV  direct  to  function automatically deletes any intermediate constraints and sets up a path descent to the vertical to waypoint using the direct flight path angle. 1.    D   key – Press.  A Direct To page will appear     with     the     cursor     over     the current TO waypoint. 2.   Line  select  key    –   Press   to   position cursor over desired waypoint. 3.   VNAV key  –  Press.    VNAV  Waypoint page     will     appear.          If     necessary, position  cursor  over  ALT  field.    If  a constraint has already been programmed, go to step 8. 4.   ALT  – Insert or verify. 5.   ENTER   key    –   Press.      Cursor   will move to OFFSET fi eld. 6.   OFFSET - If applicable, insert value in nautical miles (-99 to +99 nautical mile range). a.     If  offset  is  prior  to  the  waypoint   - Enter  range  value  and  a  (–)  will pre-fill as a default. b.     If    offset    is    beyond    waypoint    - Enter a (+) then range value. 7.   ENTER key – Press.  Cursor moves to FPA field. NOTE Direct    flight    path    angle    pre-fills    if    it    is within the valid range. 8.   Flight  path  angle  Verify  or  insert  (0.1 to 6.0 degree range). 9.   ENTER key – Press to accept waypoint  entries  and  return  to  VNAV page 1. (5)   Creating VNAV Profile Waypoints.  VNAV profile   waypoints   (#TOC,   #TOD,   and   #PRESL)   are used   to   provide   a   prediction   of   the   position   of   the aircraft   on   the   vertical   flight   path.      These   are   non- enterable  waypoints  computed  by  the  system  based on current groundspeed and  vertical speed. (a)   Top  Of  Climb  (#TOC).    Top of climb altitude   is   obtained   from   either   the   CRUISE   ALT entered  by  the  pilot  on  the  VNAV  Data  page,  or  from the altitude pre-selector setting, if available.  When the aircraft arrives at the pre-selected altitude, the system will automatically set cruise altitude to the pre-selected altitude which will provide a #TOD prediction. If   vertical   climb   constraints   are   programmed, #TOC  will  automatically  appear  as  a  waypoint  when the  aircraft  laterally  passes  the  last  vertical  waypoint that   has   a   climb   constraint.      Once   the   aircraft   has crossed  the  final  climb  constraint  waypoint,  #TOC  will then become the vertical TO waypoint.  If there are no vertical  constraints  programmed  for  climb,  #TOC  will be  displayed  as  the  first   vertical  waypoint  as  long  as the aircraft is in a climb. When the programmed cruise altitude is reached, #TOC is removed from the VNAV flight plan, and #TOD becomes the vertical TO waypoint. (b)   When   #TOC   is   the   TO   Waypoint.   The  pilot  may  obtain  range  and  ETE  to  any  altitude above the aircraft during a climb. 1.   VNAV    key    –    Press    to    display VNAV page 1. 2.   Line select key  – Press to display VNAV page 1. 3.   Alternate   altitude   –   Insert.      This value  may  be  above  or  below  the altitude  pre-select value, but must be   above   the  current  barometric altitude. 4.   ENTER key  –  Press  and  observe the change in RANGE and ETE. 5.   Previous   #TOC   altitude   setting   - Return to. NOTE Changing   CRUISE   ALT   on   the   CDU   to   a lower altitude should only be done after the aircraft    has    departed    cruise    altitude,    or #TOD  at  the  current  cruise  altitude  will  be lost. (c)   Top  Of  Descent  (#TOD).   The top of descent waypoint is the position where the aircraft will intercept  the  descent  path  at  the  cruise  altitude.    The system  calculates  the  #TOD  by  establishing  a  valid descent   reference   waypoint,   then   uses   either   the CRUISE  ALT  entered  by  the  pilot  on  the  VNAV  Data page, or the altitude pre-selector setting, if available.