e. References. Advisory Circular 25.963-1, or latest revision, Fuel Tank Access Covers, and AC 25-XX, Transport Airplane Propulsion, Engine, and APU Certification Handbook.
1114 - 1122. [RESERVED] 1377
Section 11. OPERATING LIMITATIONS 1123. SECTION 25.1517 - Rough Air Speed, VRA.
a. Rule Text.
A rough air speed, VRA, for use as the recommended turbulence penetration airspeed in § 25.1585(a)(8), must be established, which -
(1) is not greater than the design airspeed for maximum gust intensity, selected for VB; and
(2) is not less than the minimum value of VB specified in § 25.335(d); and
(3) is sufficiently less than VMO to ensure that likely speed variation during rough air encounters will not cause the overspeed warning to operate too frequently. In the absence of a rational investigation substantiating the use of other values, VRA must be less than VMO - 35 knots (TAS).
[Amdt. 25-86; 61 FR 5222, Feb. 9, 1996]
b. Intent of Rule. The purpose of this rule is to provide a means of determining the recommended speeds that must be established under § 25.1585(a)(8) .
c. Background. This rule was established consistent with the incorporation of the tuned gust criteria of Amendment 25-91.
d. Acceptable Compliance Methods. Compliance with this requirement may be shown by analysis.
e. References. None.
1124 - 1129. [RESERVED] 1451
1130. SECTION 25.1529/APPENDIX H - INSTRUCTIONS FOR CONTINUED AIRWORTHINESS.
a. Rule Text.
The applicant must prepare Instructions for Continued Airworthiness in accordance with Appendix H to this part that are acceptable to the Administrator.
The instructions may be incomplete at type certification if a program exists to ensure their completion prior to delivery of the first airplane for issuance of a standard certificate of airworthiness, whichever occurs later.
[Amdt. 25-54, 45 FR 60173, Sep. 11, 1980] H25.4 Airworthiness Limitations section.
The Instructions for Continued Airworthiness must contain a section titled Airworthiness Limitations that is segregated and clearly distinguishable from the rest of the document. This section must set forth each mandatory replacement time, structural inspection interval, and related structural inspection procedures approved under § 25.571. If the Instructions for Continued Airworthiness consist of multiple documents, the section required by this paragraph must be included in the principal manual. This section must contain a legible statement in a prominent location that reads: "The Airworthiness Limitations section is FAA approved and specifies maintenance required under §§ 43.16 and 91.403 of the Federal Aviation Regulations unless an alternative program has been FAA approved."
[Amdt. 25-54, 45 FR 60177, Sep. 11, 1980; Amdt. 25-68, 54 FR 34329, Aug. 18, 1989]
b. Intent of Rule. The purpose of this rule is to ensure continued airworthiness of the airplane by requiring that inspections, checks, and replacement of parts are performed in accordance with the requirements established for type certification.
c. Background. This rule, along with Appendix H, was created by Amendment 25-54.
d. Acceptable Compliance Methods. Review of airworthiness limitations document and applicable damage tolerance analyses and tests.
e. References. Advisory Circular (AC) 25.571-1, or latest revision, Damage Tolerance & Fatigue Evaluation of Structure.
1452
1130 - 1140. [RESERVED] APPENDIX 1. GLOSSARY OF ACRONYMS AND ABBREVIATIONS AC Advisory Circular ACO Aircraft Certification Office Admt. Amendment APU Auxiliary Power Unit CAM Civil Aeronautics Manual CAR Civil Air Regulations (predecessor of FAR) CFR Code of Federal Regulations EAS Equivalent Airspeeds FAA Federal Aviation Administration FAR Federal Aviation Regulations FR Federal Register FSS Flutter Suppression Systems JAR Joint Aviation Requirements MIL HDBK Military Handbook SAS Load Alleviation Systems SC Special Condition TSO Technical Standard Order 1453
9/1/99 AC-25-21
APPENDIX 2. INDEX OF INCORPORATED GUIDANCE MATERIAL AND
REFERENCES
1. Advisory Circulars.
The advisory circulars (AC) listed below contain information relevant to the approval of airframe systems on transport category airplanes. The latest revisions of the AC's can be obtained from the U.S. Department of Transportation, Subsequent Distribution Office, SVC-121.23, Ardmore East Business Center, 3341 Q 75th Avenue, Landover, MD 20785, USA.
AC No. Title Section Reference AC 20-53A Protection of Aircraft Fuel Systems Against Fuel Vapor Ignition Due to Lightning, dated 4/12/85
25.581 AC 20-71 Dual Locking Devices on Fasteners, dated 12/8/70 25.607 AC 20-107A Composite Aircraft Structure, dated 4/25/84 25.571, 25.581 AC 20-136 Protection of Aircraft Electrical/Electronic Systems Against the Indirect Effects of Lightning, dated 3/5/90
25.581 AC 25-7A Flight Test Guide for Certification of Transport Category Airplanes Handbook, dated 3/31/98
25.773 AC 25-14 High Lift and Drag Devices, dated 5/4/88 25.457, 25.459,
25.671, 25.701 AC 25-17 Transport Airplane Cabin Interiors Crashworthiness Handbook, dated 7/15/91
25.772, 25.785,
25.787, 25.789,
25.791, 25.793,
25.801 AC 25-335-1 Design Dive Speed, dated 10/20/97 25.335 AC 25-562-1A Dynamic Evaluation of Seat Restraint Systems & Occupant Protection on Transport Category Airplanes, dated 1/19/96
25.562, 25.789 1502
9/1/99 AC-25-21
AC No. Title Section Reference AC 25.571-1C Damage-Tolerance and Fatigue Evaluation of Structure, dated 4/29/98
25.571, 25.1529 AC 25.629-1A Aeroelastic Stability Substantiation of Transport Category Airplanes, dated 7/23/98
25.629, 25.677
25.672-1 Active Flight Controls, dated 11/15/83 25.671, 25.672 AC 25.783-1A Fuselage Doors, Hatches, and Exits, dated 12/10/86 25.783 AC 25.963-1 Fuel Tank Access Covers, dated 7/29/92 25.963 AC 25.1309-1A System Design and Analysis, dated 6/21/88 25.672, 25.701 AC 25.1329-1A Automatic Pilot Systems Approval, dated 7/8/68 25.672 AC No. Advisory Circulars To Be Issued Section Reference AC 25-XX Transport Airplane Cabin Interiors Crashworthiness Handbook
25.772, 25.785,
25.787, 25.789,
25.791, 25.793,
25.801 AC 25-XX Certification of Transport Airplane Electrical Equipment Installations All sections AC 25-XX Certification of Transport Airplane Mechanical Systems 25.699, 25.729,
25.731, 25.733,
25.735 AC 25-XX Certification of Transport Airplane Propulsion, Engine, and APU
25.865, 25.867,
25.963 1503
9/1/99 AC-25-21
2. Special Conditions.
The special conditions (SC) listed below contain information relevant to the approval of airframe systems on transport category airplanes.
SC No. Title Section Reference SC 25-ANM-23 Special Conditions issued against fly-by-wire airplanes, for Side Stick Controllers on the Airbus A320 (54 FR 3986) January 27, 1989
25.397, 25.672 SC 25-77-NW-4 Special Conditions for Boeing Model 747 Series Airplanes, issued June 27, 1977 (Non-conventional Landing Gear Arrangements)
25.477 SC 25-18-WE-7 Special Conditions for the DC-10, issued January 7, 1970 (Non-conventional Landing Gear Arrangements)
25.477 SC 25-ANM-78 Special Conditions Issued Against Fly-By-Wire Airplanes, for the Boeing Model 777 (58 FR 59646) November 10, 1993
25.672
3. Miscellaneous Documents Referenced in this Advisory Circular.
Number Title Section Reference MIL-HDBK-5 Metallic Materials and Elements for Flight Vehicle Structure
25.613, 25.693 MIL-HDBK-17 Plastics for Flight Vehicles, Composite Construction for Flight Vehicles
25.613 1504