Garmin GTN 6 Series Instructions Manual page 8

Item Description/Procedure
Battery Replacement The GTN has an internal keep-alive battery that will last about
10 years. The battery is used for GPS system information.
Regular planned replacement is not necessary. The GTN will
display a low battery' message when replacement is required.
Once the low battery message is displayed, the battery should
be replaced within 1 to 2 months. If the battery is not replaced
and becomes totally discharged, the GTN unit will remain fully
operational, but the GPS signal acquisition time may be
increased. There is no loss of function or accuracy of the GTN
unit with a dead battery. The battery must be replaced by the
Garmin factory repair station or factory authorized repair
station.
Test – Bonding Perform an electrical bonding check.
Check, GTN/GMA 1. Remove the GTN and GMA 35 (if installed) from the
2. Remove the backplate assembly from the rack(s), such that
NOTE
For GTN 7XX only, if the GMA 35 is installed, it must be
removed from its rack and the GMA 35 backplate assembly
must be removed prior to performing Step 3. When a GMA 35
bonding check is planned, perform the GMA 35 bonding check
prior to reinstalling the GTN backplate assembly to the rack.
3. Measure the resistance between each mounting rack and
In the event of bonding test failure, remove the rack and verify
that the countersunk areas around the holes, in the rack that
are used to attach the rack, are free of corrosion or any other
debris. Clean the countersunk areas using an approved
solvent per Eurocopter Standard Practices Manual (MTC 20-
02-07-401). Reattach the rack to the rails in the panel. Re-
verify the resistance between the mounting rack and nearby
exposed portion of aircraft metallic structure and ensure that
the resistance is less than or equal to 2.5 milliohms.
4. Reinstall all backplate assemblies and reinstall the GTN in
Instructions for Continued Airworthiness GTN 6XX/7XX - Eurocopter EC130 Series
Page 5 of 21
mounting rack(s)
the harnesses are disconnected.
nearby exposed portion of metallic structure and verify that
the resistance is less than or equal to 10 milliohms.
the mounting rack.
Interval
On Condition
Bond Check to be
performed every
10 years or 1800
flight hours,
whichever comes
first. The check
is to be
performed in
accordance with
Chapter 24,
Section 6.2 of the
Aircraft
Maintenance
Manual during
the EC 130 600
flight hour/24
month
inspection.
190-01007-K9 Rev. 1