AC 20-160 . 02/21/08

h. RTCA DO-306, Safety and Performance Standard for Air Traffic Data Link Services in Oceanic
and Remote Airspace (Oceanic SPR Standard), dated October 11, 2007.

i, EUROCAE document ED-112, Minimum Operation Performance Specification for Crash
Protected Airborne Recorder Systems, dated March 2003, including Amendment 1, dated July 2003, and
Amendment 2, dated September 2003.

9. How can I get this and other FAA publications?

a, You can obtain ICAO documents by writing to ICAO Document Sales, 999 University, Montreal
Quebec, Canada H3C 5H7. You may also contact the document sales office at (514) 954-8022 or visit
the ICAO website at www.ICAO.org/ .

b. You can order RTCA documents from RTCA Inc., 1828 L Street, N.W., Suite 805, Washington,
D.C. 20036-4001. Telephone (202) 833-9339, fax (202) 833-9434. You can also order through the
RTCA Internet website at www.rtca.org.

e. You can order EUROCAE documents from EUROCAE, 17 rue Hamelin, 75116 Paris France.
Telephone 33 (0) 1 4505 7188, fax 33 (0) 1 4505 7230. You can also order from the EUROCAE Internet

website at www.eurocae.org.

d. You can order copies of 14 CFR parts from the Superintendent of Documents, Government
Printing Office, P.O, Box 37154, Pittsburgh PA 15250-7954. Telephone (202) 512-1800, fax (202) 512-
2250. You can also order copies from the Government Printing Office, electronic CFR Internet website
at www.gpoaccess.gov/ecfr. Select “Title 14, Aeronautics and Space.”

e. You can find a current list of technical standard orders on the FAA Internet website Regulatory
and Guidance Library at www.airweb.faa.gov/rgl. At the same site you will find the TSO Index of

Articles, and if you select “Advisory Circulars,” you’ll be able to view and download all referenced FAA
ACs.

10. Does this AC cancel any prior ACs?

This AC does not cancel any prior ACs.

avid Hempe
Manager, Aircraft Engineering Division
Aircraft Certification Service

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@ i
se sop Ad Vv I S Oo ry
of Transportation

Federal Aviation C j rc U | a r

Administration

Subject: Onboard Recording of Controller Pilot Date: 02/21/08 AC No: 20-160
Data Link Communication In Crash Survivable Initiated by: AIR-100 Change:
Memory

1. What is the purpose of this Advisory Circular (AC)?

a. This advisory circular (AC) offers one way to achieve an acceptable level of performance for an
aircraft recording system when a controller-pilot data communication capability is installed. We wrote
this AC for aircraft equipment installers and type certificate applicants to identify design approval
requirements for data link communication recording equipment. This AC will also help Federal Aviation
Administration (FAA) staff to standardize data link communication message sets for retrieval from crash-
survivable memory.

b. This AC is not mandatory and does not constitute a regulation. In this AC, we describe one
acceptable means to gain design approval, but it is not the only means. However, if you are seeking to
gain FAA approval of your data link communication recording system by using the means described in
this AC, you must follow it in its entirety.

2. What does this AC apply to?

In this AC, we focus on aircraft recording performance and logical recording point locations for storing
controller-pilot data link communication information in onboard crash-survivable memory. These logical
point locations, also called observation points, are physical locations within airborne avionic
architectures deemed ideal for recording system data sources.

3. Why we need crash survivable memory?

We increasingly rely on data link communication technology; yet one specific shortcoming of this
technology is the lack of airborne recording of data link communication messages in crash-survivable
memory. Retrievable data link communication information in crash survivable memory gives
investigating authorities the tools for post-accident or -incident reconstruction.


AC 20-160 02/21/08

4. Related Federal Aviation Regulations. The regulations in Title 14 of the Code of Federal
Regulations (14 CFR) applying to the certification and approval of data link communication recording
equipment are listed in Figure 1 below.

FIGURE 1. Table of Applicable 14 CFR Parts

Description 14.CFR 14.CFR 14. CFR 14. CFR
Part 23 Part 25 Part 27 Part 29

Subpart F—Equipment

Function and installation. § 23,1301 § 25.1301 § 27.1301 § 29.1301

Equipment, systems, and § 23.1309 § 25.1309 § 27.1309 § 29.1309

installations.

Cockpit Voice Recorders § 23.1457 § 25.1457 § 27.1457 § 29.1457

5. What are the means of compliance to the regulations of this AC?

You may satisfy the requirements of the regulations listed in Figure 1 above by satisfactorily addressing
the instructions contained in the following sections of EUROCAE document ED-93, Minimum Aviation
System Performance Specification for CNS/ATM Message Recording Systems, dated November 1998.

a, EUROCAE document ED-93, Sections 2.3.2.1 and 2.3.2.2, Choice of Data to be Recorded
Onboard the Aircraft. These sections identify crew communication recording requirements and
recording points,

b. EUROCAE document ED-93, Appendix D.2, Controller-Pilot Data Link Communications
(CPDLC). This appendix specifies the data message set identified as “mandatory” for recording.

NOTE 1: We use the term “mandatory” only within the context of your
need to satisfactorily demonstrate the performance specifications of
EUROCAE document ED-93. For the purpose of CPDLC, ED-93,
Appendix D, defines “mandatory.”

NOTE 2: For the purposes of this AC, we consider the use of “CPDLC”
to be defined by ICAO Document 4444, Procedures for Air Navigation
Services/Air Traffic Management, Appendix 5, CPDLC Message Sets.
When applicable, we also consider other proposed message sets that
satisfy the Message Use/Intent colunm of the tables contained in ICAO
Document 4444, Appendix 5, “mandatory” for recording.

c. For data compression, this AC refers to EUROCAE document ED-112, Section

IV-2.1.2 “Recording technique”. In it we state that, “no compression methods should be
employed.”

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AC 20-160 02/21/08

d. This AC utilizes Technical Standard Order (TSO) C177, Data Link Recorder Systems, dated
July 28, 2006, or latest approved revision, to establish the proper equipment compliance criteria.

6. What is the failure condition classification?

Failure of the data link communication recording equipment is a minor failure condition. An applicant
should develop the data link communication recording equipment to, at least, the design assurance level
equal to this classification.

7. What are the maintenance program requirements?

Maintenance tasks related to the continued operation of a data link communication recording system are
not defined in this AC. See AC 20-141, Airworthiness and Operational Approval of Digital Flight Data
Recorder Systems, dated October 5, 1999, for guidance on how to develop and obtain approval for a
flight recorder maintenance program.

8. Are there any related FAA publications I should be look at?

a. AC 20-140, Guidelines for Design Approval of Aircraft Data Communication Systems, dated
August 16, 1999.

b. AC 20-141, Airworthiness and Operational Approval of Digital Flight Data Recorder Systems,
dated October 5, 1999.

ce. AC 120-70A, Operational Authorization Process for Use of Data Link Communication System,
dated December 29, 2005.

d. International Civil Aviation Organization (ICAO) International Standards and Recommended
Practices--Operation of Aircraft, Annex 6, specify onboard recording requirements. These sections

apply:

1) Part I -- International Commercial Air Transport -- Aeroplanes, §§ 6.3.1.5 and 6.3.1.5.1,
Amendment 27 Recording requirements for commercial air transport.

(2) Part II -- International General Aviation -- Aeroplanes, §§ 6.10.1.5, and 6.10.1.5.1
Amendment 19. Recording requirements for general aviation.

(3) Part III -- International Operations -- Helicopters, §§ 4.9.1.5 and Amendment 6. Recording
requirements for helicopters.

e. ICAO Document 9705/third edition, Manual of Technical Provisions for the Aeronautical
Telecommunication Network, dated April 19, 2002.

f, EUROCAE document ED-93, Minimum Aviation System Performance Specification for
Communication, Navigation and Surveillance (CNS)/Air Traffic Management (ATM) Message
Recording Systems, dated November 1998,

g. RTCA DO-290, Safety and Performance Requirements Standard for Air Traffic Data Link Services
in Continental Airspace (Continental SPR Standard), dated April 29, 2004.

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