Cirrus SR22 Pilot Operating Handbook page 385

Cirrus Design
SR22 / SR22T
System Constraints
System test at startup: Aural tone lasting approximately one second
indicates successful completion of internal system test.
Red TAWS FAIL Warning
Aural "TAWS SYSTEM FAILURE" Warning
1. TAWS power-up self-test has failed or TAWS has detected
problems with database validity, hardware status, and/or GPS
status.
White TAWS N/A Advisory
Aural "TAWS NOT AVAILABLE" Advisory
Should the 3-D GPS navigation solution become degraded or if the
aircraft is out of the database coverage area, the annunciation 'TAWS
N/A' is generated in the annunciation window and on the TAWS Page.
The aural message "TAWS NOT AVAILABLE" is generated. When the
GPS signal is re-established and the aircraft is within the database
coverage area, the aural message "TAWS AVAILABLE" is generated.
Geometric Altitude versus Measured Sea Level
TAWS uses information provided from the GPS receiver to provide a
horizontal position and altitude. This data serves as the reference for
color-coding for the TAWS Page and as an input to the TAWS Hazard
Avoidance algorithms. Because it is derived from GPS, Geometric
Altitude may differ from corrected barometric altitude. Therefore,
Geometric Altitude may be in error by as much as 100 ft and should
not be used for navigation.
P/N 13772-136
Revision 01: 01-06-10
TAWS FAIL
TAWS N/A
Section 9
Supplements
5 of 6