Figure 2-2 - Acceptable - Garmin GNS 480 Installation Manual

2.5.3.2 CDI/HSI Source Selection Annunciator
The GNS 480 has the capability to switch between its internal VOR/ILS receiver and GPS receiver when
driving a CDI/HSI. If the GNS 480 cannot be mounted such that the on-screen CDI/HSI source selection
annunciation is entirely within the acceptable area shown in Figure 2-2, a CDI/HSI Source Selection
Annunciator will be required to annunciate which source is presently driving the switched CDI/HSI.
This annunciator MUST have illuminated NAV and GPS annunciations (i.e. the GPS and NAV text must
be illuminated). The preferred location for this annunciator is on the same side of the switched CDI/HSI
as the GNS 480. A CDI/HSI with a built-in NAV/GPS annunciation may also be used in lieu of a
separate external annunciator to satisfy the annunciation requirement.
3 Upper Limit
ACCEPTABLE AREA FOR
CDI/HSI SOURCE SELECT
ANNUNCIATION
4
2 1
Lower Limit
Centerline of switched CDI/HSI
NOTES:
1. FOR AIRCRAFT WITHOUT THE BASIC INSTRUMENT 'T' CONFIGURATION, THE LOWER LIMIT OF THE ACCEPTABLE
FIELD-OF-VIEW SHOULD BE THE TWO INCHES BELOW THE BOTTOM OF THE LOWEST INSTRUMENT TYPICALLY
FOUND IN THE BASIC 'T'.
2. FOR AIRCRAFT IN WHICH THE TYPE CERTIFICATED CDI OR HSI LOCATION IS BELOW THE BASIC 'T', THE LOWER
LIMIT OF THE ACCEPTABLE FIELD-OF-VIEW SHOULD BE IN LINE WITH THE BOTTOM OF THE CDI OR HSI.
3. FOR AIRCRAFT WITHOUT THE BASIC INSTRUMENT 'T' CONFIGURATION, THE UPPER LIMIT OF THE ACCEPTABLE
FIELD-OF-VIEW SHOULD BE THE TWO INCHES ABOVE THE TOP OF THE HIGHEST INSTRUMENT TYPICALLY
FOUND IN THE BASIC 'T'.
4. IF THE ENTIRE GNS 480 ON-SCREEN CDI SOURCE SELECTION ANNUNCIATION AREA IS WITHIN THE ACCEPTABLE
AREA, AN EXTERNAL CDI/HSI SOURCE SELECTION ANNUNCIATOR IS NOT REQUIRED.
5. IF THE GNS 480 CANNOT BE INSTALLED TO PRECLUDE USE OF AN EXTERNAL CDI/HSI SOURCE SELECTION
ANNUNCIATOR, A SOURCE SELECTION ANNUNCIATOR MUST BE INSTALLED WITHIN THE ACCEPTABLE AREA
SHOWN ABOVE. THIS ANNUNCIATOR MUST BE COMPLETELY CONTAINED IN THE ACCEPTABLE AREA.
6. THE ACCEPTABLE ANNUNCIATION AREA IS WITHIN 6.5 INCHES HORIZONTALLY OF THE SWITCHED CDI/HSI. THIS
MAY NOT NECESSARILY BE THE SAME AS THE CENTERLINE OF THE INSTRUMENT 'T' AS SHOWN ABOVE.
Figure 2-2 – Acceptable CDI/HSI Source Selection Annunciation Area
GNS 480 (CNX80) Installation Manual560-0982-01 Rev A
GNS 480
ON-SCREEN CDI/HSI
SOURCE SELECTION
ANNUNCIATION AREA
(0.5" x 0.2")
4
1 in
2 in
Pilot's Instrument 'T'
6.5 in
6
Location of
GNS 480 on-screen
CDI/HSI Source
Selection
Annunciation
2 in
Basic 'T' instrument
configuration shown
2 in
6.5 in
6
Switched CDI/HSI
Installation Procedures
2-7