Subject: Approval Of Flight Guidance Systems Date: 10/16/12 Initiated by: ANM-110 AC No: 25.1329-1B Change 1
1. Purpose. This change updates Advisory Circ ular (AC) 25.1329, “Approval of Flight Guidance System s,” dated July 16, 2006 to AC 25.1329-1B, Change 1 dated 10/16/12.
a. This change removes Appendix 2, “Flight Test Procedures,” because this material has been incorporated in AC 25-7C, “Flight Test Guide for Certification of Transport Category Airplanes.”
2. Applicability.
a. The guidance provided in this document is directed to airplane manufacturers, modifiers, and operators of certain transport category airplanes.
b. The guidance in this AC is neither ma ndatory nor regulatory in nature and does not constitute a requirement. You may follow alternate FAA-approved design recommendations.
c. While these guidelines are not mandator y, they are derived from extensive FAA and industry experience in determining compliance with the relevant regulations. On the other hand, if we become aware of circumstances that convince us that following this AC would not result in compliance with the applicable regulations, we will not be bound by the terms of this AC, and we may require additional substantiation or design changes as a basis for finding compliance.
d. This material does not change, create any additional, authorize changes in, or permit deviations from, regulatory requirements.
2. Principle changes.
a. This change removes Appendix 2 fr om this AC, renumbers the remaining appendices, and changes all references to AC 25-7 from AC 25-7A to AC 25-7C, dated 10/16/12.
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b.
The change number is shown at the top of each page with the date of the change.
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Remove Pages Dated Insert Pages Dated Cover 7/17/2006 Cover, ii 10/16/2012 ii-v 7/17/2006 ii-v 10/16/2012 11-12 7/17/2006 11-12 10/16/2012 16 7/17/2006 16 10/16/2012 21 7/17/2006 21 10/16/2012 24-25 7/17/2006 24-25 10/16/2012 37 7/17/2006 37 10/16/2012 44 7/17/2006 44 10/16/2012 49 7/17/2006 49 10/16/2012 57 7/17/2006 57 10/16/2012 70 7/17/2006 70 10/16/2012 86-88 7/17/2006 86-88 10/16/2012 92 7/17/2006 92 10/16/2012 98 7/17/2006 98 10/16/2012 100 - 103 7/17/2006 100 - 103 10/16/2012 106 - 107 7/17/2006 106 - 107 10/16/2012 111 7/17/2006 111 10/16/2012
Appendices 2-4 7/17/2006 Appendices 2 - 3 10/16/2012
John Piccola Acting Manager, Transport Airp lane Directorate Aircraft Certification Service ii
Subject: Approval Of Flight Guidance Systems Date: 10/16/2012 Initiated by: ANM-110 AC No: 25.1329-1B Change 1
1. Purpose. This advisory circular (AC) describes an acceptable means for showing compliance with certain requirements of Title 14, Code of Federal Regulations (14 CFR)
25.1329, Flight guidance systems. While Part 25 contains the airworthiness standards applicable to transport category airplanes, the guidance in this AC pertains to the functions of autopilots, flight directors (FD), and automatic thrust control as well as any interactions with stability augmentation and trim functions.
2. Cancellation. Advisory Circular 25.1329-1B, dated July 17, 2006, is canceled.
3. Applicability.
a. The guidance provided in this document is directed to airplane manufacturers, modifiers, and operators of certain transport category airplanes.
b. The guidance in this AC is neither ma ndatory nor regulatory in nature and does not constitute a requirement. You may follow alternate FAA-approved design recommendations.
c. While these guidelines are not mandator y, they are derived from extensive FAA and industry experience in determining compliance with the relevant regulations. On the other hand, if we become aware of circumstances that convince us that following this AC would not result in compliance with the applicable regulations, we will not be bound by the terms of this AC, and we may require additional substantiation or design changes as a basis for finding compliance.
d. This material does not change, create any additional, authorize changes in, or permit deviations from, regulatory requirements.
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4. Related regulations, ACs, and industry documents.
a. Regulations. The following related documents are provided for information purposes and are not necessarily directly referenced in this AC. The full text of 14 CFR can be downloaded from the Internet at http://ecfr.gpoaccess.gov/cgi/t/text/textidx?c=ecfr&tpl=%2Findex.tpl. A paper copy may be ordered from the Government Printing Office (GPO), Superintendent of Documents, Attn: New Orders, PO Box 371954, Pittsburgh, PA 15250-7954.
Section Title § 25.143 Controllability and Maneuverability, General § 25.301 Loads § 25.671 Control systems, General § 25.672 Stability augmentation and automatic and power-operated systems § 25.677 Trim systems § 25.777 Cockpit controls § 25.779 Motion and effect of cockpit controls § 25.781 Cockpit control knob shape § 25.901 Installation § 25.903 Engines § 25.1301 Function and installation § 25.1303 Flight and navigations instruments § 25.1309 Equipment, systems, and installations § 25.1322 Warning, caution, and advisory lights § 25.1581 Airplane Flight Manual, General § 25.1583 Airplane Flight Manual, Operating limitations § 25.1585 Airplane Flight Manual, Operating procedures
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b. ACs. An electronic copy of the following ACs can be downloaded from the internet at http://www.faa.gov/regulations_policies/advisory_circulars/ or our Regulatory and Guidance Library (RGL) at http://rgl.faa.gov/ .
Number Title AC 20-115B RTCA, Inc., Document RTCA/DO 178B [Radio Technical Commission for Aeronautics] AC 20-138B Airworthiness Approval of Positioning and Navigation Systems AC 20-152 Design Assurance Guidance for Airborne Electronic Hardware RTCA/DO 254 AC 25-7C Flight Test Guide for Certification of Transport Category Airplanes AC 25-11A Transport Category Airplane Electronic Display Systems AC 25-12 Airworthiness Criteria for the Approval of Airborne Windshear Warning Systems in Transport Category Airplanes AC 25.672-1 Active Flight Controls AC 25.1309-1A System Design and Analysis AC 25.1419-1A Certification of Transport Category Airplanes for Flight in Icing Conditions AC 25.1581-1 Change 1 Airplane Flight Manual AC 120-28D Criteria for Approval of Category III Weather Minima for Takeoff, Landing, and Rollout AC 120-29A Criteria for Approving Category 1 and Category II Landing Minima for FAR 121 Operators AC 120-41 Criteria for Operational Approval of Airborne Windshear Alerting and Flight Guidance Systems
Note: This table repr esents the latest version of each AC at the time of publication. These individual ACs may be updated in the future, such that this table may reference a specific version of an AC that has been superseded. The latest version of each AC should always be used, even though this document may reference a previous version of an AC.
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c. Related Industry Standards. The following documents are available from the Society of Automotive Engineers (SAE). These documents can be obtained from the Society of Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale, Pennsylvania, 15096 electronically from the SAE International website, http://www.sae.org/.
Number Title SAE ARP5366 Autopilot, Flight Director and Autothrust Systems SAE ARP4754 Certification Considerations for Highly Integrated or Complex Aircraft Systems SAE ARP4761 Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment SAE ARP5288 Transport Category Airplane Head Up Display Systems SAE AS8055 Minimum Performance Standards for Airborne Head Up Display
The following docum ents are available from the RTCA, Inc. These documents can be purchased by mail from the RTCA Inc., 1150 18th Street NW, Suite 910, Washington, DC 20036; by fax, after completing the Document Order Form and faxing to 202-833- 9434; or electronically from the RTCA online store at: http://www.rtca.org/onlinecart/.
Number Title RTCA DO-178B/
EUROCAE ED-12B Software Considerations in Airborne Systems and Equipment Certification RTCA DO-160E/
EUROCAE ED–14D Environmental Conditions and Test Procedures for Airborne Equipment RTCA DO-254/
EUROCAE ED-80 Design Assurance Guidance for Airborne Electronic Hardware
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d. FAA Documents. An electronic copy of the following FAA document can be downloaded from the Internet at http://www.faa.gov/aircraft/air_cert/design_approvals/csta/publications/ .
Title Federal Aviation Administration Human Factors Team Report on: The Interfaces Between Flight Crews and Modern Flight Deck Systems – Jun 18, 1996
An electronic copy of the following FAA Order can be downloaded from the Internet at http://rgl.faa.gov/. A paper copy may be ordered from the U.S. Department of Transportation, Subsequent Distribution Office, M-30, Ardmore East Business Center, 3341 Q 75th Avenue, Landover, MD 20795.
Number Title FAA Order 8260.3 United States Standard for Terminal Instrument Procedures
John Piccola Acting Manager, Transport Airp lane Directorate Aircraft Certification Service
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CONTENTS
Paragraph Page
Chapter 1. Background
11. General 13
a. Advisory Circular (AC) 25.1329-1A 13
b. Scope 13
12. Evolution of Flight Guidance Systems (FGS) 13
a. Complexity 13
b. Guidance Considerations 13 13 – 16. [RESERVED] 13
Chapter 2. Overview of Flight Guidance Systems (FGS)
17. Purpose of FGS 15
18. FGS Components 15
a. Included in Definition 15
b. Excluded from Definition 15
19. FGS Functions 15
a. Elements of FGS 15
b. Approach and Landing System 15
c. Flight Management System (FMS) 16
d. Design Philosophy 16
e. Description of FGS Behavior and Operation 16
20. Compliance with § 25.1329 16
a. General 16
b. Relevant Paragraphs 16 Table 2-1 Cross-References § 25.1329 Paragraphs to AC Chapters 17 21 – 26 [RESERVED] 22
Chapter 3. FGS Engagement, Disengagement, Indications, and Override
27. Autopilot Engagement, Disengagement, and Indications 23
a. Autopilot Engagement 23
(1) Single Switch Action 23
(2) Engagement Status of Autopilot 23
(3) Multiple Autopilots 23
(4) Acceptable Transients 23 1
Paragraph Page
(5) Flight Director (FD) Not Engaged 23
(6) FD Engaged 24
b. Autopilot Disengagement 24
(1) General 24
(2) Autopilot Disengagement Alerts 25
(3) Quick Disengagement Control 26
(4) Alternative Means of Autopilot Disengagement 26
(5) Flightcrew Pitch Trim Input 27
28. FD Engagement, Disengagement, and Indications 27
a. FD Engagement 27
(1) General 27
(2) Guidance Cue(s) 28
(3) Reactive Windshear Guidance System 28
b. FD Disengagement 29
29. Autothrust Engagement, Disengagement, and Indications 29
a. Autothrust Engagement 29
(1) Indication 29
(2) Accessibility of Controls 29
(3) Inadvertent Engagement/Disengagement 29
(4) Automatic Engagement 29
b. Autothrust Disengagement 30
(1) Indication of Disengagement 30
(2) Inadvertent Disengagement 30
(3) Consequence of Disengagement 30
(4) Autothrust Quick Disengagement Control 30
30. Override of the FGS 31
a. General 31
b. Autopilot Override 31
(1) With Automatic Disengagement 31
(2) Without Automatic Disengagement 31
c. Autothrust Override 32
(1) Force Required 32
(2) Response to Override 32
(3) Engagement Status with Override 32
31. FGS Engagement Mode Compatibility 33
a. FGS Mode Engagement Philosophy 33
b. Engagement Mode Compatibility 33 32 — 41. [RESERVED] 33
Chapter 4. Controls, Indications, and Alerts
Paragraph Page
42. General 35
a. Human-Machine Interface 35
b. Design of Controls, Indications, and Alerts 35
c. Evaluation of Information Provided by FGS 35
43. FGS Controls 35
a. General 35
b. Design Considerations 35
(1) Differentiation of Knob Shape and Position 35
(2) Design to Support Correct Selection of Target Values 36
(3) Commonality Across Aircraft Types 36
(4) Positioning of Controls and Related Indications 36
(5) Inadvertent Operation 36
44. FGS Mode Selection, Annunciation, and Indication 36
a. Annunciation of Engagement of the FGS 36
b. Description of FGS Modes 36
c. FGS Mode Annunciations 36
(1) Active and Armed Modes 36
(2) Location 37
(3) Discriminators 37
(4) Color 37
d. Mode Changes 37
(1) Operationally Relevant Mode Changes 37
(2) Attention-Getting Features 37
(3) Use of Alerts 38
e. Failure to Engage or Arm 38
f. FGS Mode Display and Indications 38
45. FGS Alerting, Warning, Caution, Advisory, and Status 38
a. General 38
(1) Alerting Provisions 38
(2) Determination of FGS Capability 38
b. Speed Protection Alerts 38
(1) Alerts to Crew 38
(2) Alert Specifications 39
(3) Consistency 39
(4) Nuisance Alerts 39
c. Loss of Autopilot Approach Mode 39
d. Awareness of Potential Significant Transient Condition (“Bark Before Bite”) 39
(1) General 39
(2) Flightcrew Alert(s) 39
(3) Situations to Consider for an Alert 40 3
Paragraph Page
(4) Automatic Disengagement 40
46. FGS Considerations for Head Up Displays (HUD) 41
a. General 41
b. Characteristics of HUD Guidance 41
(1) Supplemental Use Display System 41
(2) External Visual References 41
(3) Interference and Occlusion 41
(4) Display Criteria 42
(5) Conformal Symbology 42
(6) Low Visibility Approach 42
(7) Clutter 42
c. HUD/Head Down Display (HDD) Compatibility 42
(1) General 42
(2) Consistency and Compatibility 42
d. Alerting Issues 43
(1) Alerts Displayed on HUDs 43
(2) Monochrome HUDs 44
(3) Mulit-Color HUDs 44
(4) Single HUD Installation 44
(5) Dual HUD Installations 44
(6) Ground Proximity Warning System (GPWS)/Traffic Alert and Collision Avoidance System (TCAS) Alerts On HUD 44
e. Upset/Unusual Attitude Recovery Guidance 44
(1) Guidance Cues 44
(2) Orientation Cues 45 47 – 51. [RESERVED] 45
Chapter 5. Performance of Function
52. General 47
a. Intended Function 47
b. Effect of System Tolerances 47
53. Normal Performance 47
a. General 47
b. Conditions to Consider 47 Table 5.1 Examples of Normal Conditions 48
c. Level of Performance 49
(1) Significant Characteristics 49
(2) Configuration Changes 49
(3) Compliance Evaluation 49
(4) Prescribed Levels of Performance 49
(5) Equivalence of Performance 49
(6) Autopilot 49 4