AC 20-138C

Historical

Advisory circular · Airworthiness Approval of Positioning and Navigation Systems

A newer version is currentThis is a historical version. AC 20-138D is the version in force, approved March 28, 2014.
Approved
May 8, 2012
Last reviewed
June 12, 2012
Cancels
AC20-138B
Cancelled by
AC20-138D
Family
AC 20-138 · 5 versions
Revision
C
14 CFR parts
21, 23, 25, 27, 29, 43, 91, 97, 121, 135

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 21, 2025.

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Appendix 7

A7-7 VASI Visual Approach Slope Indicator VDB Very High Frequency Data Broadcast VDOP Vertical Dilution of Precision VFOM Vertical Figure of Merit VFOMV Vertical Figure of Merit (velocity) VFR Visual Flight Rules VHF Very High Frequency VI Heading to Intercept per ARINC 424 VM Heading to Manual termination per ARINC 424 VNAV Vertical Navigation VOR Very High Frequency Omni-Directional Range VPL Vertical Protection Level VSWR Voltage Standing Wave Ratio URA User Range Accuracy WAAS Wide Area Augmentation System xtk Cross Track

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Appendix 8

Appendix 8. Related Documents.

A8-1. FAA Advisory Circulars.

a. AC 20-107B, Composite Aircraft Structure.

b. AC 20-115B, Radio Technical Commission for Aeronautics, Inc. Document RTCA/DO-178B.

c. AC 20-152, RTCA, Inc., Document RTCA/DO-254, Design Assurance Guidance for Airborne Electronic Hardware.

d. AC 20-153, Acceptance of Data Processes and Associated Navigation Databases.

e. AC 20-159, Obtaining Design and Production Approval of Airport Moving Map Display Applications Intended for Electronic Flight Bag Systems.

f. AC 20-163, Displaying Geometric Altitude Relative to Mean Sea Level.

g. AC 20-165, Airworthiness Approval of Automatic Dependent Surveillance - Broadcast (ADS-B) Out Equipment for Operation in the National Airspace System (NAS).

h. AC 20-174, Development of Civil Aircraft and Systems.

i. AC 21-16F, RTCA Document DO-160 versions D, E, and F, Environmental Conditions and Test Procedures for Airborne Equipment.

j. AC 21-40A, Application Guide for Obtaining a Supplemental Type Certificate.

k. AC 21-50, Installation of TSOA Articles and LODA Appliances.

l. AC 23-8B, Flight Test Guide for Certification of Part 23 Airplanes.

m. AC 23-13A, Fatigue, Fail-Safe, and Damage Tolerance Evaluation of Metallic Structure for Normal, Utility, Acrobatic, and Commuter Category Airplanes.

n. AC 23-17, Systems and Equipment Guide for Certification of Part 23 Airplanes.

o. AC 23-18, Installation of Terrain Awareness and Warning System (TAWS) Approved for Part 23 Airplanes.

p. AC 23-21 with Change 1, Airworthiness Compliance Checklists Used to Substantiate Major Alterations for Small Airplanes.

q. AC 23-22, Guidance for Approved Model List (AML) Supplemental Type Certificate (STC) Approval for Part 23 Airplane Avionics Installations.

A8-1

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Appendix 8

r. AC 23.1309-1D, Equipment, Systems, and Installations in Part 23 Airplanes.

s. AC 23.1311-1B, Installation of Electronic Displays in Part 23 Airplanes.

t. AC 23.1419-2D, Certification of Part 23 Aircraft for Flight in Icing Conditions.

u. AC 25-7A, Flight Test Guide for Certification of Transport Category Airplanes.

v. AC 25-10, Guidance for Installation of Miscellaneous, Non-Required Electrical Equipment.

w. AC 25-11A, Transport Category Airplane Electronic Display Systems.

x. AC 25-15, Approval of Flight Management Systems in Transport Category Airplanes.

y. AC 25-23, Airworthiness Criteria for the Installation Approval of a Terrain Awareness and Warning System (TAWS) for Part 25 Airplanes.

z. AC 25-1309-1A, System Design and Analysis.

aa. AC 25.1329-1, Approval of Flight Guidance Systems.

bb. AC 25.1419-1A, Certification of Part 25 Aircraft for Flight in Icing Conditions.

cc. AC 25.1529-1A, Instructions for Continued Airworthiness of Structural Repairs on Transport Airplanes.

dd. AC 27-1, Certification of Normal Category Rotorcraft.

ee. AC 29-2C, Certification of Transport Category Rotorcraft.

ff. AC 43.9-1F, Instructions for Completion of FAA Form 337.

gg. AC 43.13-1B, Acceptable Methods, Techniques and Practices – Aircraft Inspection and Repair.

hh. AC 43.13-2B, Acceptable Methods, Techniques and Practices – Aircraft Alterations.

ii. AC 90-96A, Approval of U.S. Operators and Aircraft to Operate under Instrument Flight Rules (IFR) in European Airspace Designated for Basic Area Navigation (BRNAV/RNP-5).

jj. AC 90-100, U.S. Terminal and Enroute Area Navigation (RNAV) Operations.

kk. AC 90-101A, Approval Guidance for RNP Procedures with AR.

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Appendix 8

ll. AC 90-105, Approval Guidance for RNP Operations and Barometric Vertical Navigation in the U.S. National Airspace System.

mm. AC 91-49 with Change 1, General Aviation Procedures for Flight in North Atlantic Minimum Navigation Performance Specification Airspace.

nn. AC 120-28D, Criteria for Approval of Category III Weather Minima for Takeoff, Landing, and Rollout.

oo. AC 120-29A, Criteria for Approval of Category I and Category II Weather Minima for Approach.

pp. AC 120-33, Operational Approval of Airborne Long-Range Navigation Systems for Flight within the North Atlantic Minimum Navigation Performance Specification Airspace.

A8-2. FAA Technical Standard Orders.

a. TSO-C66c, Airborne Distance Measuring Equipment (For Air Carrier Aircraft).

b. TSO-C115c, Flight Management System (FMS) Using Multi-Sensor Inputs.

c. TSO-C129a, Airborne Supplemental Navigation Equipment Using the Global Positioning System (GPS).

Note: TSO-C129a has been cancelled but is referenced here for historical purposes because manufacturers may still produce the equipment according to an existing TSOA and the equipment is still eligible for installation.

d. TSO-C144a, Passive Airborne Global Navigation Satellite System (GNSS) Antenna.

e. TSO-C145c, Airborne Navigation Sensors Using the Global Positioning System (GPS) Augmented by the Wide Area Augmentation System (WAAS).

f. TSO-C146c, Stand-Alone Airborne Navigation Equipment Using the Global Positioning System (GPS) Augmented by the Satellite Based Augmentation System (SBAS).

g. TSO-C151b, Terrain Awareness and Warning System.

h. TSO-C154c, Universal Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast (ADS-B) Equipment.

i. TSO-C161a, Ground Based Augmentation System Positioning and Navigation Equipment.

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Appendix 8

j. TSO-C162a, Ground Based Augmentation System Very High Frequency Data Broadcast Equipment.

k. TSO-C165, Electronic Map Display Equipment for Graphical Depiction of Aircraft Position.

l. TSO-C166b, Extended-Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic Information.

m. TSO-C190, Active Airborne Global Navigation Satellite System (GNSS) Antenna.

n. TSO-C194, Helicopter Terrain Awareness and Warning System.

o. TSO-C196a, Airborne Supplemental Navigation Sensors for Global Positioning System Equipment Using Aircraft-Based Augmentation.

A8-3. RTCA, Inc. Documents (RTCA/DO) documents.

a. RTCA/DO-160F, Environmental Conditions and Test Procedures for Airborne Equipment.

b. RTCA/DO-178B, Software Considerations in Airborne Systems and Equipment Certification.

c. RTCA/DO-178C, Software Considerations in Airborne Systems and Equipment Certification.

d. RTCA/DO-187, Minimum Operational Performance Standards For Airborne Area Navigation Equipment Using Multi-Sensor Inputs.

e. RTCA/DO-189, Minimum Performance Standard for Airborne Distance Measuring Equipment (DME) Operating Within the Radio Frequency Range of 960-1215 Megahertz.

f. RTCA/DO-200A, Standards for Processing Aeronautical Data.

g. RTCA/DO-201A, Standards for Aeronautical Information.

h. RTCA/DO-228 with Change 1, Minimum Operational Performance Standards For Global Navigation Satellite System (GNSS) Airborne Antenna Equipment.

i. RTCA/DO-229D, Minimum Operational Performance Standards for Global Positioning System/Wide Area Augmentation System(GPS/WAAS) Airborne Equipment.

j. RTCA/DO-235B, Assessment of Radio Frequency Interference Relevant to the GNSS L1 Frequency Band.

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Appendix 8

k. RTCA/DO-236B, Minimum Aviation System Performance Standards: Required Navigation Performance for Area Navigation.

l. RTCA/DO-246D, GNSS Based Precision Approach Local Area Augmentation System (LAAS) Signal-in-Space Interface Control Document (ICD).

m. RTCA/DO-253C, Minimum Operational Performance Standards for GPS Local Area Augmentation System Airborne Equipment.

n. RTCA/DO-254, Design Assurance Guidance for Airborne Electronic Hardware.

o. RTCA/DO-260B, Minimum Operational Performance Standards for 1090 MHz Extended Squitter Automatic Dependent Surveillance-Broadcast (ADS-B) and Traffic Information Services-Broadcast (TIS-B).

p. RTCA/DO-257A, Minimum Operational Performance Standards for the Depiction of Navigation Information on Electronic Maps.

q. RTCA/DO-282B, Minimum Operational Performance Standards for Universal Access Transceiver (UAT) Automatic Dependent Surveillance-Broadcast (ADS-B).

r. RTCA/DO-283A, Minimum Operational Performance Standards for Required Navigation Performance for Area Navigation.

s. RTCA/DO-301, Active Airborne Global Navigation Satellite System (GNSS) Antenna.

t. RTCA/DO-316, Minimum Operational Performance Standards for Global Positioning System/Aircraft-Based Augmentation System Airborne Equipment.

A8-4. Other Documents.

a. ARINC Specification 424-19, Navigation Systems Database, December 19, 2008.

Copies of this document may be requested from Aeronautical Radio Inc., 2551 Riva Road, Annapolis, Md. 21401-7435.

b. The FAA and Industry Guide to Product Certification, September 2004. Copies of this document may be obtained at http://www.faa.gov/aircraft/air_cert/design_approvals/media/CPI_guide_II.pdf.

c. GPS Standard Positioning Service Performance Standard, 4th edition, September, 2008. Copies of this document and general information related to GPS may be requested at http://pnt.gov/public/docs/2008/spsps2008.pdf.

d. Department of Defense IS-GPS-200D, Navstar GPS Space Segment/Navigation User Interface. Copies of this document may be requested from the GPS Joint Program Office, SSD/CZ, Los Angeles AFB, CA 90006. Alternatively, copies of this document may be requested A8-5

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Appendix 8

A8-6 at http://www.navcen.uscg.gov/gps/geninfo/default.htm.

e. FAA Specification Wide Area Augmentation System (WAAS), FAA-E-2892C, July 29, 2009. This document is available on-line at http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/techops/navservices/ gnss/library/documents/.

f. DOD/DOT 2008 Federal Radionavigation Plan (FRP). The FRP is published every two years. Copies may be ordered through the National Technical Information Service, Springfield, VA 22161 (DOT-VNTSC-RITA-08-02/DOD-4650.5); internet:

https://www.navcen.uscg.gov/pubs/frp2008/2008_federal_radionavigation_plan.pdf.

A8-5. How to Get Related Documents.

a. Order copies of 14 CFR parts from the Superintendent of Documents, Government Printing Office (GPO), P.O. Box 979050, St. Louis, MO 63197. For general information, telephone (202) 512-1800 or fax (202) 512-2250. You can also get copies online at the GPO electronic CFR Internet website at www.gpoaccess.gov/cfr/.

b. Order copies of RTCA documents from RTCA Inc., 1828 L Street NW, Suite 805, Washington, D.C. 20036-4007. For general information, telephone (202) 833-9339 or fax (202) 833-9434. You can also order copies online at www.rtca.org.

c. You can find copies of ACs on the FAA website at http://www.faa.gov/regulations_policies/advisory_circulars/, or www.airweb.faa.gov/rgl.

d. You can find a current list of technical standard orders on the FAA Regulatory and Guidance Library at www.airweb.faa.gov/rgl. You will also find the TSO Index of Articles on the same site.