Garmin GTXTM 327 TRANSPONDER INSTALLATION MANUAL
Brand: Garmin, Pages: 55
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GTX 327 Installation Manual Page 33
A.1 Continued Airworthiness
Other than for regulatory periodic functional checks, maintenance of the GTX 327 is “on condition” only.
Refer to the GTX 327 Maintenance Manual. Periodic maintenance of the GTX 327 is not required.
This section provides assistance to the installing agency in preparing Instructions for Continued
Airworthiness (ICA) in response to Bulletin Number HBAW 98-18, “Checklist for Instructions for
Continued Airworthiness for Major Alterations Approved Under the Field Approval Process”, effective
Aviation Authority approved installers are hereby granted permission to reference appropriate service
instructions and excerpts from this Installation Manual to accomplish the Instructions for Continued
Airworthiness. This permission does not construe suitability of the documents. It is the applicant’s
responsibility to determine the suitability of the documents for the ICA.
Following is a suggested ICA for a Garmin GTX 327 unit installation. Some of the checklist items do not
apply, in which case they should be marked “N/A” (Not Applicable).
INSTRUCTIONS FOR CONTINUED AIRWORTHINESS, GARMIN GTX 327
[Aircraft that has been altered: Registration (N-) number, Make, Model and Serial Number]
Purpose and Arrangement: This document identifies the Instructions for Continued Airworthiness
for the modification of the above aircraft by installation of a Garmin
Applicability: Applies to aircraft altered by installation of the Garmin GTX 327.
Definitions/Abbreviations: None, N/A.
Precautions: None, N/A.
Units of Measurement: None, N/A.
Referenced Publications: Garmin GTX 327 Installation Manual, P/N 190-00187-01
Garmin GTX 327 Maintenance Manual, P/N 190-00187-05
Garmin STC # SA00870WI.
Garmin GTX 327 Pilot’s Guide, P/N 190-00187-00.
Distribution: This document should be a permanent aircraft record.
2.Description of the Alteration
Installation of the Garmin GTX 327, with interface to Encoding Altimeter or Blind Encoder. Refer to
section 2.4 and Appendix B of this manual for interconnect information. Antenna installation,
removal and replacement should be in accordance with applicable provisions of AC 43.13-1B and
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3.Control, Operation Information
Refer to the GTX 327 Pilot’s Guide, Garmin P/N 190-00187-00.
Maintenance of the GTX 327 is ‘on condition’ only. Periodic maintenance is not required. Refer to
the GTX 327 Maintenance Manual.
Refer to the GTX 327 Maintenance Manual.
7.Removal and Replacement Information
Refer to section 2.4 of this manual. If the unit is removed and reinstalled, a functional check of the
equipment should be conducted in accordance with section 3.2 of this manual.
Refer to Appendix B of this manual.
9.Special Inspection Requirements
Application of Protective Treatments
Data: Relative to Structural Fasteners
Antenna installation, removal and replacement should be in accordance with applicable provisions of
AC 43.13-1A and AC 43.13-2A. Also, refer to section 2.3 of this manual.
This Section is for Commuter Category Aircraft Only
A.Electrical loads: Refer to section 1.3 of this manual.
B. Methods of balancing flight controls: N/A.
C. Identification of primary and secondary structures: N/A.
D. Special repair methods applicable to the airplane: Antenna installation, removal, and replacement
should be in accordance with applicable provisions of AC 43.13-1B and AC 43.13-2A.
No additional overhaul time limitations.
15.Airworthiness Limitation Section
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To revise this ICA, a letter must be submitted to the local FSDO with a copy of the revised FAA
Form 337, and revised ICA. The FAA inspector accepts the change by signing Block 3 and including
the following statement:
“The attached revised/new Instructions for Continued Airworthiness (date ______) for the above
aircraft or component major alteration have been accepted by the FAA, superseding the Instructions
for Continued Airworthiness (date ______).”
Flight Standards Inspectors have the resources to respond to questions regarding the ICA.
18.Implementation and Record Keeping
For major alterations performed in accordance with FAA field approval policy, the owner/operator
operating under Part 91 is responsible for ensuring that the ICA is made part of the applicable section
91.409 inspection program for their aircraft. This is accomplished when a maintenance entry is made
in the aircraft’s maintenance record in accordance with section 43.9. This entry records the major
alteration and identifies the original ICA location (e.g., Block 8 of FAA Form 337, dated ______)
along with a statement that the ICA is now part of the aircraft’s inspection/maintenance requirements.
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A.2 ENVIRONMENTAL QUALIFICATION FORM
NOMENCLATURE:GTX 327 Airborne ATC Transponder Equipment
TYPE/MODEL/PART NO.:010-00188-( ), which includes 011-00490-( )
TSO/JTSO COMPLIANCE:TSO - C74c Class 1A, JTSO - C74c Class 1A
MANUFACTURER'S SPECIFICATION AND/OR OTHER
APPLICABLE SPECIFICATION:004-00070-00 Minimum Performance Specification
MANUFACTURER: Garmin International
ADDRESS:1200 E 151st St, Olathe, Kansas 66062
Conditions RTCA DO-160D
SectionDescription of Conducted Tests
Temperature and Altitude 4.0 Equipment tested to Categories A1 & D1 except as
Low Temperature 4.5.1
High Temperature 4.5.2. & 4.5.3
In-Flight Loss of Cooling 4.5.4 Cooling air not required.
Temperature Variation 5.0 Equipment tested to Category C
Humidity 6.0 Equipment tested to Category A
Shock 7.0 Equipment tested to Category B
Vibration 8.0 Equipment tested in each aircraft type to aircraft zone
2. Aircraft Type 2 and 6 were tested to Category S2,
Vibration level B2. Aircraft Type 3, 4 and 5 were
tested to Category S, Vibration level M.
Note: Vibration level M modified to increase level
to RTCA DO-160C Curve N for Helicopters as
follows-0.1 inches peak-to-peak double amplitude
from 5 Hz to 17 Hz, 1.5 g-Pk from 17 Hz to 500 Hz.
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GTX 327 Installation Manual Page 37
Conditions RTCA DO-160D
SectionDescription of Conducted Tests
Explosion 9.0 Equipment identified as Category X, no test required
Waterproofness 10.0 Equipment identified as Category X, no test required
Fluids Susceptibility 11.0 Equipment identified as Category X, no test required
Sand and Dust 12.0 Equipment identified as Category X, no test required
Fungus 13.0 Equipment identified as Category X, no test required
Salt Spray 14.0 Equipment identified as Category X, no test required
Magnetic Effect 15.0 Equipment tested to Class Z
Power Input 16.0 Equipment tested to Category A
Voltage Spike 17.0 Equipment tested to Category A
Susceptibility18.0 Equipment tested to Category B
Susceptibility19.0 Equipment tested to Category A
Susceptibility20.0 Equipment tested for conducted susceptibility to
Category T, radiated susceptibility to Category T,
and pulse test to Category T.
Radio Frequency Emission 21.0 Equipment tested to Category B, Equipment tested to
Category M up to 2 GHz.
Lightning Induced Transient
Susceptibility22.0 Equipment identified as Category XXXX, no test
Lightning Direct Effects 23.0 Equipment identified as Category X, no test required
Icing 24.0 Equipment identified as Category X, no test required
Electrostatic Discharge 25.0 Equipment identified as Category X, no test required
Remarks: In the Y-Axis vibration sweep, there were two critical frequencies identified very close
together at 160 Hz and 181 Hz. At the end of the vibration test cycle the two frequencies had
combined into one frequency at 179 Hz. There was no change in unit performance.