400W Series Installation Manual Page 1-15190-00356-02 Rev. GTSO Deviation7. 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 operationallimitation 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 theeffective mask angle through operational limitations.c. The ability to further increase the effective mask angle, through operational limitations, to a levelcommensurate 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 assessingthe operational limitation.e. The ability to use -128 dBmic as the minimum SBAS satellite signal-in-space for the purpose ofassessing the operational limitation. NOTE 1C146acont’d8. Garmin was granted a deviation from TSO-C146a paragraph 2.1.1.9 to use 20 seconds (instead of 10seconds) to reacquire a dropped satellite under the conditions described in the paragraph. The 20 secondperiod is the time period specified by the newer DO-229D. NOTE 1Note 1: No. 7 deviation is applicable with GPS software version 2.X or installations with an antenna listed in section1.4.8.2.No. 8 deviation is applicable with GPS software version 3.0 or newer.1.6.3 ETSO AuthorizationTable 1-5. ETSO AuthorizationModels Function ETSO Minimum Performance StandardGPS 400WGNC 420WGNC 420AWGNS 430WGNS 430AW● ● ILS Glideslope ETSO-2C34f EUROCAE ED-47B● ● ILS Localizer ETSO-2C36f EUROCAE ED-46B● ● ● ● VHF COM Transmitter ETSO-2C37eEUROCAE ED-23BClass 4 & 6 for GNC 420W, GNS 430WClass 3 & 5 for GNC 420AW, GNS430AW● ● ● ● VHF COM Receiver ETSO-2C38e EUROCAE ED-23BClass C & E● ● VOR Receiver ETSO-2C40c EUROCAE ED-22B● ● ● ● ● Multipurpose Display ETSO-C113 SAE AS 8034● ● ● ● ● GPS WAAS ETSO-C146 RTCA/DO-229CClass 3
