TM 1-1510-218-10 3B-63 12.   "Check gear" will be announced immediately after 300-foot announcement if gear is not down. 13.   "Two hundred" at 200 feet AGL. 14.   "Check gear" will be announced immediately after 200-foot announcement if gear is not down. 15.   "One hundred" at 100 feet AGL. 16.   "Check gear" will be announced immediately after 100-foot announcement if gear is not down. 17.   "Minimum, minimum" at decision height. 18.   "Localizer"   at   1.3   to   1.5   dots   either side   of   center   of   beam.      Will   be repeated    three    times    at    4-second intervals. 19.   "Glideslope"  at  1.3  to  1.5  dots  above or   below   center   of   beam.      Will   be repeated    three    times    at    4-second intervals. 20.   "Altitude, altitude" at excessive  deviation from altitude selected on the altitude alerter. 21.   "Check   trim"   when   trim   failure   has occurred.        Will    be    repeated    three times at 4-second intervals. 22.   "Autopilot" when autopilot has disconnected. b.    Normal Operation. (1)   Turn-on    Procedure.        The    GPAAS    is operable   when   the   following   conditions   have   been met. 1.   Battery switch – ON. 2.   Avionics master switch – On. 3.   GPAAS POWER circuit breaker – Set. 4.   RADIO ALTM circuit breaker – Set. 5.   VA FAIL annunciator light – Extinguished. (2)   GPAAS Ground Check. 1.   GPAAS voice advisory  VOL control  – Full clockwise. 2.   VOICE OFF switch-indicator – Extinguished. 3.   Audio control panel – Set audio level. 4.   VA FAIL annunciator light – Extinguished. 5.   Radio altimeter  DH SET control  – Set to 200 feet. 6.   Radio altimeter  TEST switch  – Press and  hold.    "Minimum,  minimum"  will be  annunciated  once  followed  by  the illumination of the VA FAIL light. 7.   Radio altimeter TEST switch – Release. c.     GPAAS Modes of Operation.  The GPAAS operates in the following modes of operation. (1)   Aural "Two Thousand" Advisory (Mode 1).        The    aural    advisory    "Two    Thousand" indicates that the aircraft is at a radio altitude of 2000 feet   AGL.      This   advisory   is   cancelled   when   valid information   from   the   radio   altimeter   is   lost,   during climb, or whenever the aircraft is out of the operating altitude range of the radio altimeter. (2)   Hundred   Foot   Increment   Aural   Altitude Advisories   (Mode   2).      The   aural   advisories   "One Thousand,    Nine    Hundred,    Eight    Hundred,    Seven Hundred,  Six  Hundred,  Five  Hundred,  Four  Hundred, Three Hundred, Two Hundred, One Hundred" indicate that  the  aircraft  is  at  the  associated  radio  altitude  in feet   AGL.      This   advisory   is   cancelled   when   valid information   from   the   radio   altimeter   is   lost,   during climb, or whenever the aircraft is out of the operating altitude range of the radio altimeter. (3)   Aural "Localizer" Advisory (Mode 3).  The aural advisory "Localizer" indicates that the aircraft has deviated   from   the   center   of   the   localizer   beam   in excess  of  1.3  to  1.5  dots.    The  localizer  advisory  is armed when a valid localizer signal is detected and the aircraft  is  below  1000  feet  above  ground  level.    It  will be repeated no more that 3 times at 4-second intervals unless  the  aircraft  is  returned  to  less  than  1.3  to  1.5 dots   from   the   center   of   the   localizer   course.      The localizer  advisory  is  disabled   when  a  valid  localizer signal has been lost, during climb, below the decision height  set  on  the  radio  altimeter,  or  if  the  navigation receiver is not tuned to a localizer frequency.