190-01279-01
GTS 8XX Part 23 AML STC Maintenance Manual
Rev. 2
Page 2-4
2.5 Ground Plane
Ground plane definition varies with airframe type and aircraft model, as defined in Table 2-2. Refer to the
periodic test and reconditioned resistance values corresponding to these ground plane definitions when
performing the equipment bonding test per Section 4.3. Ensure that all GTS 8XX system antenna coaxial
cables are disconnected during resistance checks.
Table 2-2 Ground Plane Definitions and Ground Path Resistance Requirements
Notes:
[1] Diamond DA 40 and DA 40F with Diamond OSB 40-004/3 incorporated, or aircraft with
similar factory-installed lightning protection supporting IFR operation.
Aircraft Type/Model
Ground
Reference
Maximum Resistance Between
GTS 8XX Chassis and Ground
Reference (m
Ω
)
Notes
Periodic Test
Reconditioned
Metal airframe
Nearby metallic
structure
10.0
2.5
Tube airframe with fabric cover
Nearby metallic
structure
10.0
2.5
Composite VFR-only Models
Diamond
DA 40, DA 40F
Instrument panel
50.0
25.0
Composite IFR Models
Cessna
LC40-550FG,
LC41-550FG,
LC42-550FG
Nearby aluminum
lightning ground
bar/strip
10.0
5.0
Cirrus
SR20,
SR22,
SR22T
Local grounded
structure (such as
seat support
structure, entry
step)
10.0
5.0
Diamond
DA 40,
DA 40F
Nearby structure
lightning ground
tube
10.0
5.0
[1]
DA 42,
DA 42 N-MG
Nearby lightning
ground
10.0
5.0
