Limitations; Operation; Tso-C146 Agps/Waas Limitations - Garmin GNS 480 Installation Manaul

5 Limitations

5.1 Operation

There are no Part 23 aircraft type limitations. All functions of the GNS 480 meets the appropriate design
assurance qualifications for primary or secondary for airplane Class I, Class II, Class III, and Class IV in
accordance with AC 23.1309-1C Figure 2. The TSO authorizations with the RTCA/DO178B software
levels by function are listed in Table 3-1. TSO deviations are listed in Section 1.4.3 of this manual.
TSO-C146a defines loss of function of en route, terminal, nonprecision approach, or precision approach
navigation data as a major failure condition. AC 23.1309-1C provides guidance for IFR airplanes that
classifies total loss of function as a major failure condition, and loss of primary means of function as
minor if two navigation systems are installed. One method to meet the major failure condition for loss of
function is to install redundant systems. It is recommended that the aircraft be equipped with at least two
independent navigation receivers and two independent communication transceivers for IFR use. For
independent navigation systems, two GNS 480 units may be used, or a combination of GNS 480 and an
independent NAV/COM unit may be
IFR operations. Refer to AC 23.1309-1C.
The installation of a GNS 480 into an aircraft does not alter the operational approvals previously granted
to that aircraft. Additional operation approvals may require FAA evaluation of all the systems installed in
a particular aircraft and is outside the scope of the GNS 480 STC.
5.2 TSO-C146a GPS/WAAS Limitations
Due to the equipment's TSO qualified performance in tracking low-elevation-angle satellites, operational
limitations may be required based upon the GPS antenna or GPS software used in the installation. If the
AML STC is used as the basis for approval, the appropriate limitations are included in the AFMS provided
with the STC. However, if other airworthiness approval is obtained, the following limitations must be
included in the Aircraft Flight Manual or Aircraft Flight Manual Supplement if an antenna listed in Table
1-2 or GPS software version 2.x (or earlier) is used:
The limitations and AFM/AFMS inclusion do not apply to VFR-only installations.
The equipment does not comply with US 14 CFR part 91, SFAR 97 requirements for TSO-C146a
equipment. Until complete compliance is demonstrated and approved by the FAA, authorization to
conduct any GPS or WAAS operation under Instrument Flight Rules (IFR) requires that:
a) Aircraft using the GPS or WAAS capability of the GNS 480 (CNX80) Series navigation
equipment under IFR must be equipped with an approved and operational alternate means of
navigation appropriate to the flight with the exception of oceanic and remote operations.
b) For flight planning purposes, if an alternate airport is required, it must have an approved
instrument approach procedure other than GPS or RNAV that is anticipated to be operational and
available at the estimated time of arrival. All equipment required for this procedure must be
installed and operational.
c) For flight planning purposes, Garmin Prediction Program part number 006-A0154-02 (with the
<insert installed antenna model number/part number> antenna selected) should be used to
confirm the availability of RAIM for the intended flight in accordance with the local aviation
authority guidelines for TSO-C129a equipment. WAAS NOTAMs (or their absence) and generic
prediction tools do not provide an acceptable indication of the availability for the 500W Series
equipment.
GNS 480 (CNX80) Installation Manual
used. This will support a System Safety Assessment of minor for
NOTE
560-0982-01 Rev L
Limitations
5-1