TM 1-1510-225-10 3B-189 Two    types    of    Resolution    Advisories    may    be displayed, a preventive and a corrective.  A preventive advisory  indicates  a  vertical  speed  range  or  pitch  that is  to  be  avoided  while  maintaining  your  present  flight path.      A   corrective   advisory   indicates   a   necessary change  in  flight  path  by  displaying  a  vertical  speed range or pitch to be flown to.  Either advisory serves to ensure   that   the   maximum   separation   between   your aircraft  and  an  intruder  is  maintained.    Refer  to  Table 3B-110. Table 3B-109.  Resolution Advisory Chart ALTITUDE (FEET) SECONDS TO CPA Below 900 AGL RA not issued if descending Below 1100 AGL RA not issued if climbing 1000 – 2350 AGL 15 2350 AGL – 5000 BARO 20 5000 – 10,000 BARO 25 10,000 – 20,000 BARO 30 20,000 – Above BARO 35 Table 3B-110.  Resolution Advisory Inhibits Radio Altitude Resolution Advisory Status Below 1450 FT AGL INCREASE DESCENT RA inhibited Below   1000   FT   AGL descending; Below 1200 FT AGL climbing DESCEND RA inhibited Below    900    FT    AGL descending; Below 1100 FT AGL climbing All    RA's    inhibited    9TA ONLY) and TA Aural Message inhibited. (a)   Preventive Advisory.  The preventive advisory  is  an  RA  that  occurs  when  the  TCAS  has determined  that  a  threat  exists  but  the  current  vertical speed  or  pitch  will  result  in  sufficient  separation  from the  intruder.    The  general  conditions  for  a  preventive advisory   occur   when   the   intruder   is   within   300   to 800  feet   (relative   altitude),   the   range   separation   is decreasing, and there is approximately 25 seconds to the  closest  point  of  approach.    The  RA  display  will show   a   red   vertical-speed  arc  indicating  speeds  or pitches to avoid.  No other action is advised. (b)   Corrective  Advisory.    This  is  an  RA that  occurs  when  the  TCAS  has  determined  that  the flight crew should take action to change vertical speed or pitch to avoid an intruder. The  advisory  occurs  when  the  threat  aircraft  is within 300 feet (relative altitude), the range separation is decreasing, and there is approximately 25 seconds to   the   closest   point   of   approach.      The   TCAS   will provide  the  flight  crew  with  a  recommended  vertical speed or pitch to provide maximum aircraft separation at   the   closest   point   of   approach.      The   corrective advisory consists of one or two red arcs and a green arc.        As    with    the    preventive    advisory,    the    red represents vertical speed or pitch ranges that are to be avoided. The  pilot  should  act  on  the  corrective  advisory command  within  approximately  5  seconds  after  it  is issued.    Strengthened  (increased  climb  or  increased descents) resolution advisories or reversals represents more   urgent   situations   and   should   be   acted   upon within not more than 2.5 seconds. NOTE The   RA   (either   preventive   or   corrective) may downgrade to a TA when the intruder begins  diverging  from  your  own  aircraft.   When the  RA changes to a TA, the vertical speed maneuver guidance arcs are removed and the aural message, "Clear Of Conflict" is annunciated. g.  Pop-Up Traffic.  When no TA or RA situation exists for a climb, the display will appear as shown in Figure 3B-145. When an   RA  or  TA  is  issued,  a  display  of  all intruders  within  range  pops  up  on  the  indicator  and continues to be displayed until all TA's and RA's clear.   The  display  will  revert  to  showing  VERT  SPEED  X 1000 FPM when clear. h.  Full Time Traffic.  When the full time mode is selected,   the   VERT   SPEED   X1000   FPM   legend   is removed and the own-aircraft symbol, range ring, and range  legend  are  continually  displayed  as  shown  in Figure 3B-146.   If  no  traffic  is  present,  the  display  will be   the   same   except   for   the   absence   of   the  traffic symbols. i.    TA  Only.    In  the  TA-only  mode  the  display will  appear  as  shown  in  Figure  3B-147.    The  TA  only mode can be manually selected on the transponder/TCAS  control  panel,  or  automatically  in certain situations such as when below 100 feet AGL.   The  display  will  show  the  ONLY  TA  flag  in  message slots 1 and 2 and that the 6 nm range is selected.