Garmin GNC 420 - Manual (Page 234)

GNC 420(A) Pilot’s Guide and Reference
SECTION 13 – MESSAGES,
ABBREVIATIONS, & NAV TERMS
13-6
Message Description
Poor GPS coverage
The GPS receiver cannot acquire a sufficient number of satellites to compute a position and
provide navigation.
Power down and re-
initialize
The GNC 420 cannot calculate a position due to abnormal satellite conditions. The unit is
unusable until power has been cycled off and back on. Abnormal satellite conditions may
exist, an alternate means of navigation may be needed.
RAIM is not available
Receiver Autonomous Integrity Monitoring (RAIM) has determined that sufficient GPS
satellite coverage does not exist for the current phase of flight. (The CDI/HSI NAV flag also
appears.) Select an alternate source for navigation guidance.
RAIM not available
from FAF to MAP
waypoints When performing an instrument approach, Receiver Autonomous Integrity Monitoring (RAIM)
has determined that sufficient GPS satellite coverage does not exist to meet the required
protection limits. Select an alternate source for navigation guidance.
RAIM position warning
Although sufficient GPS satellite coverage may exist, Receiver Autonomous Integrity
Monitoring (RAIM) has determined the information from one or more GPS satellites may
be in error. The resulting GPS position may be in error beyond the limits allowed for the
current phase of flight. Cross-check the position with an alternate navigation source. If the
warning occurs during a final approach segment (FAF to MAP), execute the published missed
approach.
Scheduler message --
[user entered text] The user-entered scheduler message time has expired, and the scheduler message is
displayed.
Searching the sky
The GNC 420 is searching the sky for GPS satellite almanac data or the GPS receiver is in
AutoLocate Mode. Allow the unit to complete data collection (approximately five minutes)
before turning it off.
Select auto sequence
mode
The OBS Key was pressed, disabling auto sequencing of waypoints (in a flight plan or
instrument procedure). The OBS Key should be pressed again to enable auto sequencing,
because 1) no destination waypoint has been selected or 2) the GPS receiver cannot currently
determine its position.
Set course to [###]°
The course select for the external CDI (or HSI) should be set to the specified course. The
message only occurs when the current selected course is greater than 10° different from the
desired track.
Steep turn ahead
This message appears approximately one minute prior to a turn in one of the following three
conditions: 1) the turn requires a bank angle in excess of 25° in order to stay on course,
2) the turn requires a course change greater than 175°, or 3) during a DME arc approach the
turn anticipation distance exceeds 90 seconds.
190-00140-20 Rev. K