c. Background.
(1) Amendment 4b-8 of the Civil Air Regulations (CAR). This subject was first addressed in part 4b of the CAR under Amendment 4b-8, effective May 17, 1958. A new § 4b.659 was included which required appropriate protection of the airplane against failure of high energy rotors when such rotors were incorporated in any equipment on the airplanes.
Section 4b.659 read "Equipment incorporating high energy rotors shall be demonstrated as capable of containing a failed rotor or shall be so located that failure will not affect the ability of the airplane to continue safe flight."
(2) Amendment 4b-12 of the Civil Aeronautics Manual (CAM). Amendment 4b-12, effective May 13, 1962, deleted § 4b.659 because it was surmised that its substance was covered by the provisions of § 4b.606 (which later became § 25.1309) which is concerned with the reliability of all equipment, systems, and installations.
(3) Amendment 25-41. Amendment 25-41 added § 25.1461 as a result of an Airworthiness Review Program conducted in 1975. This new section added requirements for protection against the failure of equipment containing high energy rotors. Experience had demonstrated that failures which release the energy stored in these rotors may result in engine or structural damage, fires, or injury to occupants.
d. Policy/Compliance Methods. Compliance to §25.1461(c) is accomplished if it can be shown by test that equipment containing high-energy rotors can contain any failure of the rotor that occurs at the highest speed obtainable with normal speed control devices inoperative. In general, three phase induction motor driven fans do not have speed control devices. Fan speed is a function of the input power frequency supplied to the device.
(1) Because of the absence of speed controls, these fans can be treated as an extension of the aircraft power generating system. To comply with § 25.1461(c), the minimum test speed would be at the highest speed obtainable with power generating system speed control devices inoperative (speed control device is the mechanical system that governs generator shaft speed).
In the event of such a failure, generating system controls will limit frequency. Exceeding those limits would require further multiple failures. These higher order failures do not have to be considered to comply with § 25.1461(c).
(2) For external ground power operation, the same frequency limits are applicable. The cart (or other) providing power must fail, the cart protective overfrequency protection must fail, and the airplane protective systems must fail to trip the external power contactor. In addition, an uncontained fan rotor burst on the ground is classified differently as it is not a safety of flight issue.
e. References. None.
Chapter 4. OPERATING LIMITATIONS AND INFORMATION
Section 1. OPERATING LIMITATIONS
72. SECTION 25.1529 - 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 [Amdt. 25-54, 45 FR 60173, Sep. 11, 1980] ensure their completion prior to delivery of the first airplane for issuance of a standard certificate of airworthiness, whichever occurs later.
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 60173, 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 subject was not addressed in either section 4b of the Civil Air Regulations (CAR) or part 25 of Title 14, Code of Federal Regulations (14 CFR). This rule was added, along with Appendix H, by Amendment 25-54.
d. Policy/Compliance Methods. For guidance on compliance with this requirement, refer to the preamble of this rule and the airworthiness limitations document.
e. Reference. The address for ordering the latest revision of the advisory circular listed below can be found in the Appendix to this AC.
Advisory Circular 25-19, Certification Maintenance Requirements.
APPENDIX 1, CROSS REFERENCE FOR SELECTED SECTIONS OF PART 25, CAR 4b/CAM 4b
DISTRIBUTION TABLE
Revised Section Former Section Revised Section Former Section
25.671 4b.320 (less (b)) 25.869(b) 25.1443(b) & (c) [4b.658]
25.672 not applicable 25.869(c) 25.1451 [4b.651(f)]
25.699 4b.323(e) & (f) 25.1001 4b.437 (less (e) (last sent.))
25.701 4b.324 25.1183 4b.333, 4b.483
25.703 not applicable 25.1185 4b.481
25.729 4b.334, -2 25.1189 4b.382
25.731 4b.335(a) & (b) 25.1301 4b.600, 4b.601
25.733 4b.336 25.1309 4b.606
25.735 4b.335 less (a), (b) 25.1416 not applicable 4b.337, -4 (1st sent.) 25.1419 4b.640 (less intro, 3rd sent.
25.771 4b.350 25.1431 4b.650
25.773 4b.351 25.1433 4b.658
25.775 4b.352 25.1435 4b.653, 4b.654, 4b.655
25.777 4b.353 25.1438 not applicable
25.783 4b.356, -1(last sent) 25.1439 4b.651 (less (a)-(g) 4b.356-2(a)/1st sent 25.1441 4b.651(a)
25.831 4b.371, 4b.371-1 25.1443 4b.651(b)
25.832 not applicable 25.1445 4b.651(c), 4b.651-5a
25.833 4b.372 25.1147 4b.651(d)
25.841 4b.374, 4b.375, -1 25.1449 4b.651(e)
25.843 4b.376 25.1450 not applicable
25.851 4b.380 (less (c)), 4b.383 (2nd sent. of (a) &
(b)(3)
25.1453 4b.651(g)
25.854 not applicable 25.1455 4b.660
25.855 4b.382, 4b.384 25.1461 not applicable
25.857 not applicable
25.858 not applicable
25.863 4b.385
APPENDIX 2, GLOSSARY OF ACRONYMS
AC Advisory Circular ACO Aircraft Certification Office AD Airworthiness Directive AFM Airplane Flight Manual AIA Aerospace Industries Association AIR Aircraft Certification Service ARAC Aviation Rulemaking Advisory Committee ARP Aerospace Recommended Practice (SAE) BTMS Aircraft Brake Temperature Monitor System CAA Civil Aeronautics Administration (US) CAR Civil Air Regulations CAM Civil Aeronautics Manual CFR Code of Federal Regulations DER Designated Engineering Representative ECS Environmental Control System EICAS Engine Indication and Crew Alerting System FAR Federal Aviation Regulations IIDSS Inflight Ice Detection Sensing Systems JAA Joint Aviation Authorities JAR Joint Airworthiness Requirements KE Kinetic Energy NOE Non-original Equipment NTSB National Transportation Safety Board OAT Outside Air Temperature OBOGS On-Board Oxygen Generating System OEM Original Equipment Manufacturer PBE Protective Breathing Equipment PMA Parts Manufacturer Approval PPM Parts Per Million PPMV Parts Per Million by Volume QTR Qualification Test Report R&D Research & Development RTO Rejected Take-off SAE Society of Automotive Engineers SLD Supercooled Large Droplets SLE Sea Level Equivalent STC Supplemental Type Certificate TAD Transport Airplane Directorate TAT Total Air Temperature TC Type Certificate TSO Technical Standard Order TWA Time-Weighted-Average 171
APPENDIX 3, INDEX OF ADVISORY CIRCULAR REFERENCES
The advisory circulars listed below contain information relevant to the approval of mechanical systems on transport category airplanes. They 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 R eference
20-32B Carbon Monoxide (CO) Contamination in Aircraft- 25.831 Detection and Prevention, November 24, 1972, or latest revision, ACE-110
20-33B Technical Information Regarding Civil Aeronautics All sections Manuals 1, 3, 4a, 4b, 5, 6, 7, 8, 9, 13 and 14, May 1, 1975, or latest revision, AIR-200
20-34D Prevention of Retractable Landing Gear Failures, 25.729 August 8, 1980, or latest revision, AFS-340
20-36S Index of Articles (Materials, Parts, Processes and All sections Appliances ) Certified Under the Technical Standard Order System, September 1, 1993, or latest revision, AFS-613
20-41A Substitute Technical Standard Order (TSO) Aircraft All sections Equipment, April 5, 1977, or latest revision, AIR-120
20-42C Hand Fire Extinguishers for use in Aircraft, 25.851 March 7, 1984, or latest revision, ACE-110
20-62D Eligibility, Quality, and Identification of Approved All sections Aeronautical Replacement Parts, May 24, 1996, or latest revision, AFS-340
20-73 Aircraft Ice Protection, April 21, 1971, or latest revision, 25.1419 AIR-120
20-97A High-Speed Tire Maintenance and Operational Practices, 25.733 May 13, 1987, or latest revision, AFS-340
20-99 Antiskid and Associated Systems, May 27, 1977, or 25.735 latest revision, ANM-100
20-110J Index of Aviation Technical Standard Orders, All sections May 30, 1997, or latest revision, AIR-120
20-117 Hazards Following Ground Deicing and Ground 25.1419 Operations in Conditions Conducive to Aircraft Icing, December 17, 1982; Chg. 1, April 15, 1983, or latest revision, AFS-200
20-128A Design Considerations for Minimizing Hazards Caused 25.1435 by Uncontained Turbine Engine and Auxiliary Power Unit Rotor and Fan Blade Failures, March 25, 1997, or latest revision, ANM-114
21-16C Radio Technical Commission for Aeronautics (now called All sections RTCA Inc.) Document DO-160C, February 14, 1990, or latest revision, AIR-120
21-23 Airworthiness Certification of Civil Aircraft Engine, 25.735 Propellers, and Related Products, July 7, 1987, or latest revision, AIR-4
23.729-1 Landing Gear Doors and Retraction Mechanism, March 26, 23.729 1984, or latest revision, ACE-110. For information only.
23-1419-2 Certification of Part 23 Airplanes for Flight in Icing 23.1419 Conditions, January 3, 1992, or latest revision, ACE-100
25-7A Flight Test Guide for Certification of 25.729, 25.731 Transport Category Airplanes, March 31, 1998, or 25.733, 25.735 latest revision, ANM-110 25.773
25-9A Smoke Detection, Penetrating, and Evacuation Tests and 25.831, 25.854 Related Flight Manual Emergency Procedures, 25.855, 25.858 January 6, 1994, or latest revision, ANM-110
25-14 High Lift and Drag Devices, May 4, 1988, or latest 25.699, 25.703 revision, ANM-112 25.671, 25.672
25-16 Electrical Fault and Fire Prevention and Protection, 25.869 April 5, 1991, or latest revision, ANM-111
25-17 Transport Airplane Cabin Interiors Crashworthiness 25.773, 25.857 Handbook, July 15, 1991, or latest revision, ANM-114 25.858, 25.869 172
25-18 Transport Category Airplanes Modified for Cargo Service, 25.857 January 6, 1994, or latest revision, ANM-114
25-19 Certification Maintenance Requirements, November 28, 25.1309 1994, or latest revision, ANM-113
25-20 Pressurization, Ventilation, and Oxygen Systems 25.831, 25.841 Assessment for Subsonic Flight Including High Altitude Operation, September 10, 1996, or latest revision, ANM-111
25-21 Certification of Transport Airplane Structure, 25.671, 25.672 September 1, 1999, ANM-110 25.701
25.672-1 Active Flight Controls, November 15, 1983, or latest 25.672 revision, ANM-110B
25.703-1 Takeoff Configuration Warning Systems, March 17, 1993, 25.703 or latest revision, ANM-111
25.773-1 Pilot Compartment View for Transport Category Airplanes, 25.773 January 8, 1993, or latest revision, ANM-111
25.783-1 Fuselage Doors, Hatches, and Exits, December 10, 1986, 25.783 or latest revision, ANM-110
25.963--1 Fuel Tank Access Covers, July 29, 1992, or latest 25.729 revision, ANM-112
25.1309-1A System Design Analysis, June 21, 1988, or latest 25.1309, 25.1435 revision, ANM-112
25.1419-1 Certification of Transport Category Airplanes for 25.1419 Flight in Icing Conditions, August 18, 1999, or latest revision, ANM-112
25.1455-1 Waste Water/Potable Water Drain System Certification 25.1455 Testing, March 11, 1985, or latest revision, ANM-112
27-1A Certification of Normal Category Rotorcraft, dated 25.731 July 30, 1997, or latest revision, ASW-111
29-2B Certification of Transport Category Rotorcraft, July 30, 1997, 25.731 or latest revision, ASW-111
43.13-1A Acceptable Methods, Techniques and Practices 25.729, 25.731, Aircraft Inspection and Repair (with Errata Sheet), dated 25.733, 25.735 April 17, 1972, or latest revision, AFS-600
43.13-2A Acceptable Methods, Techniques, and Practices Aircraft All sections Alterations, includes Chg. 1, dated June 9, 1977; Chg. 2, dated Oct. 30, 1989, or latest revision, AFS 340
91-6A Water, Slush, and Snow on the Runway, May 24, 1978, 25.109, 25.735 or latest revision, AFS-430
91-13C Cold Weather Operation of Aircraft, July 24, 1979, 25.109, 25.735 or latest revision, AFS-806
91-51A Effect of Icing on Aircraft Control and Airplane De-ice and 25.1419 Anti-Ice Systems, July 19, 1996, or latest revision, AFS-820
120-38 Transport Category Airplanes Cabin Ozone Concentrations, October 10, 1980, or latest revision, AFS-260 25.832
120-39 Hazards of Waste Water Ice Accumulation Separating From 25.1455 Aircraft in Flight, October 31, 1980, or latest revision, AFS-331
120-42A Extended Range Operation with Two Engine Airplanes 25.1435 (ETOPS), December 30, 1988, or latest revision, AFS-400
120-58 Pilot Guide for Large Aircraft Ground Deicing, September 30, 25.1419 1992, or latest revision, AFS-420
121.195-1A Operational Landing Distances for Wet Runways: Transport 25.109, 25.735 Category Airplanes, June 19, 1990, or latest revision, AFS-430
145-4 Inspection, Retread, Repair and Alterations of Aircraft Tires, September 27, 1982, or latest revision, AFS-340 25.733
*25-XX Cargo Compartment Fire Extinguishing or Suppression System s, date TBD 25.857
*25-XX Class B and F Cargo Compartments, date TBD 25.857
*25-XX Propulsion Systems Handbook 25.863, 25.943, (Mega AC) date TBD 25.1001, 25.1183,
25.1185, 25.1189
*25-XX Electrical Systems Handbook (Mega AC) 25.1301, 25.1309, date TBD 25.1325
*NOTE: The designation "25-XX" means that a draft AC exists for the subject. Upon approval, the "XX" will be replaced with a numerical reference identification code.
APPENDIX 4, INDEX OF INCORPORATED GUIDANCE MATERIAL AND
REFERENCES
1. FAA Memorandums and Letters Referenced in this AC:
Copies of the memorandums and letters are available from the FAA Transport Airplane Directorate, 1601 Lind Ave. SW, Renton, WA 98055, USA.
SectionSubject D ate
25.729 Protection of Equipment in Wheel Wells, Dec. 4, 1997 § 25.729(f)(1)
25.729 Landing Gear Position Indication System - July 12, 1988 “Backup Requirement” - Section 25.729(e)
25.729 Flap System/Landing Gear Warning System Dec. 19, 1983 Tie-In
25.729 Landing Gear Position Indication System June 3, 1983
25.729 Landing Gear Slush Tests April 22, 1983
25.733 Approval of Retreaded Tires by Similarity March 1, 1995
25.733 Approval of Nonretreadable Tires - August 18, 1988 Qualif ication Testing
25.733 Approval Method for Substitute Tires April 14, 1988
25.733 Replacement of Bias Ply Tires with Radial Feb. 7, 1984 P ly Tires
25.733 Certification Program for Replacing Bias Jan. 12, 1984 Tires with Radial Tires, Part 25 Transports;
All Weight Categories
25.733 Certification of Radial Tire Installation March 28, 1984
25.733 Critical Conditions & Maximum Ramp Jan. 26, 1981 Weight Definitions
25.735 Carbon Brake Refurbishment April 11, 1996 (redensification)
25.735 Parts Manufacturer Approval for a April 9, 1996 Non-U.S. Location: § 21.303(g)
25.735 Certification of Replacement Brakes: May 19, 1992 Non-U.S. Location
25.735 Parking Brake Testing March 20, 1992,
25.735 Worn Brake Requirements for Non- Feb. 18, 1992 Origina l-Equipment Parts (letter)
25.735 Determination of Allowable Feb. 23, 1990, Mar. 2, 1990 Worn Brake Limits
25.735 Credit for Reverse Thrust in Worn April 28, 1989 Brake Testing 171
25.735 Certification of Brake Replacement Mar. 16, 1989, Dec. 27, 1988, Com ponents - Performance and March 16, 1988
25.735 Ground Equipment-Brake Cooling Unit Dec. 27, 1988
25.735 Certification Requirements for Asbestos- Dec. 16, 1987 Free Brake Linings
25.735 Determination of Certification Requirements Oct. 26, 1987 for Brake Components - Performance
25.735 Approval of Brake Components Utilizing July 27, 1987 New Brake Friction Material
25.735 Maximum Quick Turnaround Times August 19, 1983
25.735 Dynamometer Test Guidelines to Establish March 2, 1990 Brake Wear Limits (letter)
25.831 Ventilation During Takeoff with the May 20, 1983 Environmental Control System Turned Off
25.831 Fresh Air and Normal Operating Conditions Sept. 10, 1997
25.831 Cabin Altitude Limit; § 25.841(a) Jan. 12, 1994
25.832 Use of Operational Limitations March 31, 1997
25.832 Meaning of the Term Time-Weighted Average Oct. 26, 1987 in § 25.832 of the FAR
25.833 Standards for Certification of Combustion March 14, 1948 Heaters
25.841 Rapid Equalization of Pressure June 21, 1982
25.841 Access to a Pressurized Cargo Compartment June 25, 1986 in the Engine Burst Zone During High Altitud e Operation
25.841 Cabin Altitude Limit; § 25.841(a) Jan. 12, 1994
25.843 Pressure Tests for Compliance with 25.843(a) Feb. 21, 1990
25.854 Approval of Lavatory Smoke Detectors Oct. 28, 1991
25.854 Approval of Lavatory Fire Extinguishers March 31, 1997 Containing Agents Other Than Halon
25.857 Main Deck Cargo Compartment Fire June 6, 1997 Protection Certification Procedures
25.857 Cargo Compartments Sept. 13, 1988
25.857 Class A Cargo Compartments February 8, 1996
25.857 Class E Cargo Compartments March 21, 1991
25.857 Class E Cargo Compartments July 3, 1990
25.858 Smoke Detection Certification Testing June 18, 1997
25.858 Smoke Detection Certification Testing Feb. 11, 1993
25.858 Smoke Detection Certification Testing Dec. 3, 1992, Dec. 15, 1992
25.1419 Inflight Ice Detection Systems Jan. 13, 1998
25.1419 Aircraft Mounted Ground Ice Detection Oct. 10, 1996 System s
25.1419 Roll Control in Supercooled Large Droplets July 23, 1997
25.1435 Hydraulic Fuel Contamination April 20, 1995 172