Page 7-4
G900X/G950 Installation and Maintenance Manual – GRS 77 and GMU 44
Revision D
190-00719-00
7.4.3 TSO/ETSO
Deviations
Table 7-5 contains a list of applicable TSO and SAE deviations for the GRS 77 and GMU 44.
Table 7-5. GRS 77/GMU 44 TSO/ETSO Deviations
TSO Deviation
1. Garmin was granted a deviation from TSO-C3d to use RTCA DO-160D instead of RTCA
DO-160B as the standard for Environmental Conditions and Test Procedures for Airborne
Equipment.
TSO-C3d
(GRS 77)
2. Garmin was granted a deviation from TSO-C3d to use RTCA DO-178B instead of RTCA
DO-178A to demonstrate compliance for the verification and validation of the computer
software.
1. Garmin was granted a deviation from TSO-C4c to use SAE AS 8001 instead of SAE
AS 396B for Minimum Performance Standards and Environmental Standards.
2. Garmin was granted a deviation from SAE Aerospace Standard AS 8001 to use RTCA
DO-160D instead of RTCA DO-138 as the standard for Environmental Conditions and Test
Procedures for Airborne Equipment.
TSO-C4c
(GRS 77)
Neither TSO-C4c nor SAE Aerospace Standard AS 8001 specifies use of a standard for
software development; Garmin used RTCA DO-178B as the standard for Software
Considerations in Airborne Systems and Equipment Certification.
1. Garmin was granted a deviation from ETSO-C4c to use SAE AS 8001 instead of SAE
AS 396B for Minimum Performance Standards and Environmental Standards.
2. Garmin was granted a deviation from SAE Aerospace Standard AS 8001 to use RTCA
DO-160D instead of RTCA DO-138 as the standard for Environmental Conditions and
Test Procedures for Airborne Equipment.
ETSO-C4c
(GRS 77)
3. Neither ETSO-C4c nor SAE Aerospace Standard AS 8001 specifies use of a standard
for software development; Garmin used RTCA DO-178B as the standard for Software
Considerations in Airborne Systems and Equipment Certification.
1. Garmin was granted a deviation from TSO-C6d to use RTCA DO-160D instead of RTCA
DO-160B as the standard for Environmental Conditions and Test Procedures for Airborne
Equipment.
2. Garmin was granted a deviation from TSO-C6d to use RTCA DO-178B instead of RTCA
DO-178A to demonstrate compliance for the verification and validation of the computer
software.
TSO-C6d
(GRS 77 and
GMU 44)
3. Garmin was granted a deviation from TSO-C6d to use SAE AS 8013A instead of SAE
AS 8013 as the Minimum Performance Standard.
1. Garmin was granted a deviation from ETSO-C6d to use RTCA DO-160D instead of SAE
AS 8013 as the standard for Environmental Conditions and Test Procedures for Airborne
Equipment.
ETSO-C6d
(GRS 77 and
GMU 44)
2. Garmin was granted a deviation from ETSO-C6d to use SAE AS 8013A instead of SAE
AS 8013 as the Minimum Performance Standard.