Airplane Flight Manual Supplement

190-00682-02 Rev. D Hawker Beechcraft C90A and C90GT King Air
Page 49 of 117
DUAL GPS/SBAS FAILURE (AMBER “DR” OR “LOI” ON HSI)
LOSS OF GPS/SBAS NAVIGATION DATA
When both GPS/SBAS receivers are inoperative or GPS navigation information is not available or
invalid, the G1000 system will enter one of two modes: Dead Reckoning mode (DR) or Loss Of
Integrity mode (LOI). The mode is indicated on the HSI by an amber “DR” or “LOI”. Which mode
is active depends on the distance from the destination airport in the active flight plan.
If the LOI annunciation is displayed, revert to an alternate means of navigation appropriate to the
route and phase of flight or periodically cross-check the GPS guidance to other, approved means
of navigation.
In Dead Reckoning mode, the MAP – NAVIGATION MAP will continue to be displayed with a
ghosted aircraft icon in the center and an amber ‘DR’ overwriting the icon. Aircraft position will be
based upon the last valid GPS position, then estimated by Dead Reckoning methods. Changes in
true airspeed, altitude, or winds aloft can affect the estimated position substantially. Dead
Reckoning is only available in Enroute mode; Terminal and Approach modes do not support DR.
Course deviation information will be displayed as an amber CDI on both PFDs and will remain for
up to 20 minutes after GPS position data has been lost. The autopilot and/or flight director may
be coupled in GPS mode while the system is in Dead Reckoning mode. Refer to the G1000
Cockpit Reference Guide for further information. Revert to an alternate means of navigation
appropriate to the route and phase of flight.
If Alternate Navigation Sources (ILS, LOC, VOR, DME, ADF) Are Available:
1. Navigation ................................................................................. USE ALTERNATE SOURCES
If No Alternate Navigation Sources Are Available:
DEAD RECKONING (DR) MODE - ACTIVE WHEN THE AIRPLANE IS GREATER THAN 30 NM
FROM THE DESTINATION AIRPORT.
2. Navigation - Use the airplane symbol and magenta course line on the map display.
NOTE
• ALL INFORMATION NORMALLY DERIVED FROM GPS TURNS AMBER. ALL OF THIS
INFORMATION WILL BECOME LESS ACCURATE OVER TIME.
• TAWS IS INOPERATIVE
• DR mode uses heading, true airspeed, last known wind data, and the last known GPS
position to estimate the airplane’s current position. DR information will be available for a
maximum of 20 minutes.
• MAP – TRAFFIC MAP display is not dependent on GPS information. The position of
displayed traffic relative to the airplane symbol on the map is still accurate.