Garmin GNC 420AW, Installation Manual

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400W Series Installation Manual Page 1-15
190-00356-02 Rev. G
TSO Deviation
7. Garmin was granted a deviation from TSO-C146a from RTCA/DO-229C paragraphs 2.1.1.10, 2.1.1.7,
2.1.1.8.1, 2.1.1.8.2, 2.1.1.9, 2.1.2.1, 2.1.3.1, 2.1.4.1.4, 2.1.4.1.5 and 2.1.5.1 in the form of an operational
limitation to achieve an equivalent level of safety. The operational limitation is based on:
a. The ability to use antennas that may not meet the minimum gain performance requirements of DO-228.
b. The ability to mitigate the effects of the different gain characteristics of those antennas by increasing the
effective mask angle through operational limitations.
c. The ability to further increase the effective mask angle, through operational limitations, to a level
commensurate with test conditions used in the original TSO qualification tests.
d. The ability to use -128 dBmic as the minimum GPS satellite signal-in-space for the purpose of assessing
the operational limitation.
e. The ability to use -128 dBmic as the minimum SBAS satellite signal-in-space for the purpose of
assessing the operational limitation. NOTE 1
C146a
cont’d
8. Garmin was granted a deviation from TSO-C146a paragraph 2.1.1.9 to use 20 seconds (instead of 10
seconds) to reacquire a dropped satellite under the conditions described in the paragraph. The 20 second
period is the time period specified by the newer DO-229D.
NOTE 1
Note 1: No. 7 deviation is applicable with GPS software version 2.X or installations with an antenna listed in section
1.4.8.2.No. 8 deviation is applicable with GPS software version 3.0 or newer.
1.6.3 ETSO Authorization
Table 1-5. ETSO Authorization
Models Function ETSO Minimum Performance Standard
GPS 400W
GNC 420W
GNC 420AW
GNS 430W
GNS 430AW
● ● ILS Glideslope ETSO-2C34f EUROCAE ED-47B
● ● ILS Localizer ETSO-2C36f EUROCAE ED-46B
● ● ● ● VHF COM Transmitter ETSO-2C37e
EUROCAE ED-23B
Class 4 & 6 for GNC 420W, GNS 430W
Class 3 & 5 for GNC 420AW, GNS
430AW
● ● ● ● VHF COM Receiver ETSO-2C38e
EUROCAE ED-23B
Class C & E
● ● VOR Receiver ETSO-2C40c EUROCAE ED-22B
● ● ● ● ● Multipurpose Display ETSO-C113 SAE AS 8034
● ● ● ● ● GPS WAAS ETSO-C146
RTCA/DO-229C
Class 3