Text-only reference. Published from the recorded official FAA General Chapter 2 PDF. Diagrams, photographs, and figure artwork are not reproduced here; use the official FAA PDF for those materials.
2-21 14 CFR Part 91—General Operating and Flight Rules Subpart A—General As mentioned in the brief overview of the regulation portion earlier in this chapter, this part is actually addressing the operation of the aircraft. For example, 14 CFR part 91, section 91.7(a) states “no person may operate a civil aircraft unless it is in an airworthy condition.” We learned earlier that this term means that the aircraft conforms to its approved type design and is in condition for safe operation. When the pilot performs a preflight inspection, they are making a determination concerning the “condition for safe operation.” The pilot does not usually determine “conformity to type design” unless they perform a review of the maintenance records. However, since that is fundamental to the definition of airworthy, it is still part of their responsibility. Therefore, a professional and ethical technician wants to help the customer understand their responsibilities in maintaining and documenting the airworthiness of the aircraft.
Subpart E—Maintenance, Preventive Maintenance, and Alterations Section 91.401—Applicability Although this subpart describes in general the rules regarding maintenance, preventive maintenance, and alteration, certain sections do not apply if the aircraft is operated in accordance with 14 CFR part 121, 125, 129, or 135. Section 91.403—General The owner/operator holds the primary responsibility for maintaining the aircraft in airworthy condition. This includes compliance with all applicable ADs and is the reason that the FAA sends new AD notes to the registered owners of the affected aircraft. All maintenance performed must be accomplished in accordance with 14 CFR part 43.
Compliance with the appropriate manufacturer maintenance manuals and ICA is also required. Mandatory replacement times, inspection intervals, and related procedures as outlined in the FAA-approved operations specifications must also be complied with. Section 91.405—Maintenance Required The owner/operator is required to have the appropriate inspections made, and to have discrepancies repaired in accordance with part 43. They are also required to ensure that the appropriate entries have been made in the maintenance records. Any inoperative instruments or equipment must be properly placarded as inoperative.
Section 91.407—Operation after maintenance, preventive maintenance, or alteration Whenever the aircraft has undergone maintenance, preventive maintenance, rebuilding or alteration, it must have been approved for RTS and a proper entry made in the maintenance records. If the maintenance that was done could have appreciably changed the flight characteristics, an appropriately rated pilot must perform an operational flight check of the aircraft and must make an entry of the flight in the maintenance records. If ground testing and inspection can show conclusively that the maintenance has not adversely affected the flight characteristics, no flight test is required.
Section 91.409—Inspections This paragraph identifies various types of inspection applicable to the civilian aircraft fleet. Paragraph (a) defines the requirement for an annual inspection. However, there are certain exceptions to this regulation: 1. An aircraft that carries a special flight permit, a current experimental certificate, or a light-sport or provisional airworthiness certificate; 2. An aircraft inspected in accordance with an approved aircraft inspection program under part 125 or 135 of this chapter and so identified by the registration number in the operations specifications of the certificate holder having the approved inspection program; 3. An aircraft subject to the requirements of paragraph (d) or (e) of this section; or 4. Turbine-powered rotorcraft when the operator elects to inspect that rotorcraft in accordance with paragraph (e) of this section.
Annual inspections are usually the inspection method associated with small “general aviation” aircraft. If this same aircraft is used for hire (including flight instruction for hire), then the aircraft must also be inspected every 100 hours of time in service. This requirement for a 100-hour inspection to be conducted on an aircraft may be exceeded by as much as 10 hours if the aircraft is en route to reach a facility that will be conducting the inspection. Any time accrued between 100 and 110 hours is subtracted from the hours remaining before the next 100-hour inspection. Since aircraft used for hire only generate revenue when they are flying, any time that the aircraft is “down for inspection” can result in a loss of income for the owner/operator.
Therefore, the FAA has made provision to minimize the impact of the 100-hour and annual inspection requirement. The owner/operator may petition the local FSDO for approval of a progressive inspection program. This program breaks the complete inspection of the aircraft into smaller, less time-consuming steps. (Refer to 14 CFR part 43, Appendix D.) This inspection may be either performed or supervised by a technician holding an IA. The program must ensure at all times that the aircraft is airworthy. The owner/operator must submit an inspection schedule with their application 2-22 to the FAA. This schedule must identify the time intervals (hours or days) when routine and detailed inspections are to be accomplished. (Refer to 14 CFR part 43, section 43.15.) Just as with the 100-hour inspection, a 10-hour maximum extension of a specified inspection interval is allowed if the aircraft is en route. A change in the inspection interval is also allowed for changes in service experience. If the progressive inspection is discontinued, the aircraft is again subject to the traditional annual and 100-hour inspections.
Other inspection programs that may be applicable to other aircraft are a continuous airworthiness inspection program and an approved aircraft inspection program (AAIP). The former program is applicable to either a part 121 or 135 carrier, but the latter program is limited to part 135 operators only. Finally, the owner/operator may use either a current inspection program recommended by the aircraft manufacturer or one established by the owner/operator and approved by the local FSDO. Any subsequent changes to that program must also be approved by the local FSDO. There may be an instance when the operator of an aircraft wishes to change from one type of inspection program to another. In that case, the time in service, calendar times, or cycles of operation from the current program must be carried over to the subsequent program.
Section 91.411—Altimeter System and Altitude Reporting Equipment Tests and Inspections Commonly referred to as “the 411 test,” this section specifies the requirements for testing the static pressure system, each altimeter instrument, and each automatic pressure altitude reporting system every 24 calendar months. The static system must also be tested any time it has been “opened and closed,” except for the normal use of the system drain and alternate static system pressure valves. If the automatic pressure altitude reporting system of the air traffic control (ATC) transponder is either installed or subjected to maintenance actions, the system must also be tested per Appendix E of 14 CFR part 43.
Due to the inherent design and accuracy of this system, only the aircraft manufacturer, a properly-rated repair station, or a certificated airframe mechanic may perform these tests. The airframe technician may only perform the inspection and test of the static pressure system. Calibration and maintenance of related instruments is specifically prohibited to the technician by the language of 14 CFR part 65, section 65.81 and specifically allowed in 14 CFR part 145, section 145.59 for repair stations holding an instrument rating. TSO’d items are considered to be “tested and inspected” as of the date they were manufactured. The maximum altitude that the system was tested is the maximum altitude that the aircraft can be flown instrument flight rules (IFR) in controlled airspace.
Section 91.413—ATC Transponder Tests and Inspections This “413 test” is the other test required every 24 months. Whenever the ATC transponder is installed or has undergone maintenance, the complete system must be tested and inspected in accordance with Appendix E of 14 CFR part 43. The transponder itself must be tested and inspected in accordance with Appendix F of 14 CFR part 43. As with the 411 test, only certain persons are authorized to conduct the tests. They are the manufacturer of the aircraft, a properly certificated repair station, or the holder of a continuous airworthiness maintenance program under 14 CFR part 121 or 135.
Section 91.415—Changes to Aircraft Inspection Programs If the FAA determines that the inspection program established and approved under either 14 CFR part 91, section 91.409 or 91.1109 must be revised to ensure continued safety and adequacy of the program, the owner/operator must make the necessary changes as identified by the Administrator. If the owner/operator desires to contest this request, they must petition the FAA to reconsider their request to change the program within 30 days of receiving the change request from the FAA. Section 91.417—Maintenance Records The understanding and implementation of this section is fundamental to the aircraft industry, in general, and the aircraft owner/operator, in specific. A professional maintenance technician must be knowledgeable of this section and be able to help the owner/operator understand it.
[Figure 2-10] This section identifies four types of records— two are quite specific (paragraphs a and d) and two are more general: (a)(1) and (a)(2). Paragraph (a) refers to the 411 and 413 testing that requires testing every 24 months. Therefore, records must be kept for that length of time. Paragraph (d) refers to the installation of fuel tanks in the cabin or cargo area. The FAA Form 337 authorizing this installation must be kept on board the aircraft all the time. Note: Other than this paragraph, there is no requirement that the maintenance records of the aircraft be carried on the aircraft. In fact, there are very logical reasons to not do so in most cases. The two biggest concerns are damaged or lost records. It is much safer to retain the logs in a filing system in the office. It is also a very wise idea to have the logbook copied or scanned and retained at a separate location should a catastrophic event (fire, flood, tornado, hurricane, and so forth) occur at the site the original records are retained.
Subparagraph (a)(1) then lists those records that are later 2-23 defined in (b)(1) as being retained for 1 year or until the work is repeated or superseded. Subparagraph (a)(2) specifies the records that are permanent records and are identified in subparagraph (b)(2) as those that must be transferred with the aircraft. Refer to the chart for further clarification. [Figure 2-10] Paragraph (c) requires that all of the maintenance records mandated by this section be made available upon request to the Administrator or any authorized representative of the NTSB. Furthermore, the owner/operator must provide the Form 337 required to be aboard the aircraft whenever additional fuel tanks are installed in either the passenger compartment or the baggage compartment, per paragraph (d), to any law enforcement officer upon request.
Section 91.419—Transfer of Maintenance Records When an aircraft is sold, it is logical that the records are transferred with it. They may be either in plain language or coded. The purchaser may elect to permit the seller to retain the actual records; however, if that occurs the purchaser (now the current owner/operator) must still make these records available to either the FAA or the NTSB upon request. Section 91.421—Rebuilt Engine Maintenance Records This section presents the term “zero time.” Although not truly given as a definition, the wording of the regulation is very clear that an aircraft engine, when rebuilt by the engine manufacturer or an agency approved by the manufacturer, may be given a new maintenance record showing no previous operating history. This new record must include a signed statement with the date it was rebuilt, any changes incorporated by compliance with AD notes, and compliance with any of the manufacturer’s SB.
Civil Air Regulations (CAR)
Prior to 1926, access to flying was uncontrolled. No licensing or certification was required. By the middle of the 1920s, it became obvious that unregulated private and commercial flying was dangerous. There was a growing awareness and acceptance that regulation could improve safety and encourage growth in aviation. Therefore in 1926, the aviation industry requested Congress to enact federal legislation to regulate civil aviation. Thus, the Air Commerce Act of 1926 provided for the: 1. Establishment of airways. 2. Development of aviation aids. 3. Investigation of aviation accidents. 4. Licensing of pilots.
5. Certification of aircraft. The Civil Air Regulations (CARs) were part of the original certification basis for aircraft first certified in the 1940s, 1950s, and 1960s by the Civil Aviation Authority (CAA). Therefore, the CARs may still be needed as a reference for these older aircraft or as a standard for minor changes to older aircraft designs. [Figure 2-11] CAR 3—Airplane Airworthiness—Normal, Utility, Aerobatic, and Restricted Purpose Categories As the name implies, this specific regulation is the basis for the current 14 CFR part 23 regulation [ Figure 2-1]. It has the following subpart categories: • A—Airworthiness Requirements • B—Flight Requirements—General • C—Strength Requirements—General • D—Design and Construction—General • E—Powerplant Installations—Reciprocating Engines • F—Equipment Some examples of CAR 3 aircraft are Piper PA 22, PA 28, PA 32, and Cessna 182, 195, and 310.
Note: The “CAR” acronym actually has two interpretations: Civil Air Regulations and Canadian Aviation Regulations. The technician must clearly understand the difference and recognize when one or the other is appropriate. CAR 4a—Airplane Airworthiness This regulation was originated in 1936 and last amended on December 15, 1952. The subparts included in this regulation are: • A—Airworthiness Requirements • B—Definitions • C—Structural Loading Conditions, General Structural Requirements • D—Proof of Structure • E—Detail Design and Construction • F—Equipment • G—Powerplant Installation • H—Performance • I—Miscellaneous Requirements Initially, this regulation was the basis for establishing the design requirements for virtually all produced aircraft in the 1930s, 1940s, and 1950s. Eventually CAR 3 evolved as the regulatory material specific to small aircraft, and CAR 4a and b focused on regulatory requirements for large aircraft.
2-24 14 CFR 91.417 Maintenance Records Sections 91.411 and 91.413. paragraph (a): Retain for 2 years. Paragraph (d): FAA Form 337 for extended range fuel tanks in cabin or cargo. Keep on board A/C. Paragraph (a)(1): Maintenance, Preventive Maintenance, Alterations and all Inspections. Paragraph (a)(2): Records of total time in service for A/F, each engine, each propeller and each rotor. Currents status of life-limited parts of A/F engine, prop, rotor, or app. Paragraph (b)(3) List of defects furnished to the Owner/Operator in accordance with Section 43.11. Description of work. Date of completion.
Signature and Certificate Number of person approving RTS. Time since last overhaul for items that are required to overhaul. Current inspection status. Current status of applicable ADs. Copies of Form 337. Retained until defects are repaired and the A/C is approved for RTS. Paragraph (b)(2): Retain and transfer with A/C. It is very important to review the TCDS for each aircraft. For example, The Cessna 140 was certified as a landplane under CAR 3, but under CAR 4a as a ski-plane or seaplane. Another example of a more current and larger aircraft is the Gulfstream 1159 and 1159A. The former is certified under CAR 4b, but the latter is certified to 14 CFR part 25.
Suspected Unapproved Parts (SUP) There are four types of aircraft parts: 1. Good parts with good paperwork. 2. Good parts with bad paperwork. 3. Bad parts with “good” (bogus) paperwork. 4. Bad parts with bad paperwork. The first of those listed represents properly authorized parts that, when properly installed, are approved parts, and the aircraft can be returned to service. The last of those listed represent unauthorized and unapproved parts. The technician should be alert for these and must never install them on an aircraft. The center two categories of parts represent suspected unapproved parts. If either the physical part or the paperwork associated with the part is questionable, it is best to contact the shop foreman, shift supervisor, or the assigned quality individual to discuss your concerns. Suspected unapproved parts (SUPs) should be segregated and quarantined until proper disposition can be determined. Contacting the manufacturer of the product is a good way to start gathering the facts concerning the product in question. Refer to the current version of AC 21-29, Detecting and Reporting Suspected Unapproved Parts, for additional information.
Current contact information for submitting a SUP Notification can be found at www.faa.gov.
Other FAA Documents
Advisory Circulars (AC) AC refers to a type of publication offered by the FAA to provide guidance for compliance with airworthiness regulations. They provide guidance such as methods, procedures, and practices acceptable to the Administrator for complying with regulations. ACs may also contain explanations of regulations, other guidance material, best practices, or information useful to the aviation community. They do not create or change a regulatory requirement. The AC system became effective in 1962. It provides a single, uniform, agency-wide system that the FAA uses to deliver advisory material to FAA customers, industry, the aviation community, and the public.
Unless incorporated into a regulation by reference, the content of ACs are not binding on the public. ACs are issued in a numbered-subject system corresponding to the subject areas of the FARs (14 CFR, Chapter 1, Federal Aviation Administration) and Chapter 3, Commercial Space Transportation, Federal Aviation Administration, Department of Transportation, Parts 400–450. An AC is issued to provide guidance and information in a designated subject area or to show a method acceptable to the Administrator for complying with a related federal aviation regulation. Because of their close relationship to the regulations, ACs are arranged in a numbered system that corresponds to the subject areas of the CFRs. In some series, consecutive numbers may 2-25 Predecessor Regulations to the Federal Aviation Regulations (14 CFR) Aeronautical Bulletins 7A 7F 7G 7H 7J 14 26 Airworthiness Requirements for Aircraft Airworthiness Requirements for Aircraft Components and Accessories Airworthiness Requirements for Engines and Propellers Alteration and Repair of Aircraft Special Requirements for Air Line Aircraft Relative Lift Distribution in Any Biplane Requirements for Approved Type Certificates Design Information for Aircraft
Civil Air Regulations (CAR)
CAR 1 CAR 2 CAR 3 CAR 4a CAR 4b CAR 6 CAR 7 CAR 8 CAR 9 CAR 10 CAR 13 CAR 14 CAR 18 CAR 40 Special CAR 425-C Special CAR 406 Certification, Identification, and Marking of Aircraft and Related Products Aircraft Identification Mark Airplane Airworthiness—Normal, Utility, Acrobatic, and Restricted Purpose Categories Airplane Airworthiness Airplane Airworthiness: Transport Categories Rotorcraft Airworthiness: Normal Category Rotorcraft Airworthiness: Transport Categories Aircraft Airworthiness: Restricted Category Aircraft Airworthiness: Limited Category Certification and Approval of Import Aircraft and Related Products Aircraft Engine Airworthiness Aircraft Propeller Airworthiness Maintenance, Repair, and Alteration of Certificated Aircraft and of Aircraft Engines, Propellers and Instruments Scheduled Interstate Air Carrier Certification and Operation Rules Provisional Certification and Operation of Aircraft Application of Transport Category Performance Requirements to C-46 Type Aircraft Civil Aeronautics Manual (CAM) CAM 1 CAM 2 CAM 3 CAM 4a CAM 4b CAM 6 CAM 7 CAM 8 CAM 9 CAM 10 CAM 13 CAM 14 CAM 18 Certification, Identification, and Marking of Aircraft and Related Products Production Certificates Airplane Airworthiness: Normal, Utility, and Acrobatic Categories Airplane Airworthiness Airplane Airworthiness: Transport Categories Rotorcraft Airworthiness Rotorcraft Airworthiness: Transport Categories Aircraft Airworthiness: Restricted Category Aircraft Airworthiness: Limited Category Certification and Approval of Import Aircraft and Related Products Aircraft Engine Airworthiness Aircraft Propeller Airworthiness Maintenance, Repair, and Alteration of Airframes, Powerplants, Propellers, and Appliances 2-26 be missing. These numbers were either assigned to ACs still in preparation that will be issued at a later date or were assigned to ACs that have been canceled.
The AC Numbering System There are three parts to an AC number, as in 25-42-C. • The first part of the number identifies the subject matter area of the AC. This corresponds to the part of the FAA’s regulations. In the above example, this would be part 25. • The second part of the number, beginning with the dash, is a sequential number within each subject area. In the above example, this would be the 42nd AC relating to part 25. • The third part of the number is a letter assigned by the originating office showing the revision sequence if an AC is revised. The first version of an AC does not have a revision letter. In the above example, this is third revision, as designated by the “C.” [Figure 2-12] Airworthiness Directives (AD) In accordance with 14 CFR part 39, the FAA issues ADs in response to deficiencies and/or unsafe conditions found in aircraft, engines, propellers, or other aircraft parts. ADs require that the relevant problem must be corrected on all aircraft or aircraft parts using the same design. ADs are initiated as either proposed, corrective, or final (telegraphic) via the Federal Register. The Federal Register is the official daily publication of the United States Government. It is the printed method of informing the public of laws that are enacted or will be enacted.
Electronic versions of ADs are available from the Federal Register and from the Regulatory and Guidance Library. You can search by manufacturer, model, or AD number. All ADs are “incorporated by reference” into part 39 and are considered final. ADs must be followed to remain in compliance with the FAA. Once an AD has been issued, a person/company is authorized to use the affected aircraft or part only if it has been corrected in accordance with the AD. Types of Airworthiness Directives (AD) Three types of ADs are issued: • Notice of Proposed Rulemaking (NPRM), followed by a Final Rule • Final Rule; Request for Comments • Emergency ADs The standard AD process is to issue an NPRM followed by a Final Rule. After an unsafe condition is discovered, a proposed solution is published as an NPRM and solicits public comment on the proposed action. After the comment period closes, the final rule is prepared, taking into account all substantive comments received with the rule perhaps being changed as warranted by the comments. The preamble to the final rule AD provides response to the substantive comments or states there were no comments received.
In certain cases, the critical nature of an unsafe condition may warrant the immediate adoption of a rule without prior notice and solicitation of comments. This is an exception to the standard process. If time for the terminating action to be accomplished is too short to allow for public comment (that is, less than 60 days), then a finding of impracticability is justified for the terminating action, and it can be issued as an immediately adopted rule. The immediately adopted rule is published in the Federal Register with a request for comments. The Final Rule AD may be changed later if substantive comments are received.
An Emergency AD is issued when an unsafe condition exists that requires immediate action by an owner/operator. The intent of an Emergency AD is to rapidly correct an urgent safety deficiency. An Emergency AD may be distributed by fax, letter, or other methods. It is issued and effective to only the people who actually receive it. This is known as “actual notice.” All known owners and operators of affected U.S.-registered aircraft, or those aircraft that are known to have an affected product installed, are sent a copy of an Emergency AD. To make the AD effective to all persons, a follow up publication of the Final Rule AD in the Federal Register is critical. This Final Rule AD must be identical to the Emergency AD and is normally published in the Federal Register within 30 days of the Emergency AD issue.
AD Content Generally, ADs include: • A description of the unsafe condition • The product that the AD applies to • The required corrective action or operating limitations or both • The AD effective date • A compliance time • Where to go for more information • Information on alternative methods of compliance with the requirements of the AD AD Number ADs have a three-part number designator. The first part is the calendar year of issuance. The second part is the biweekly period of the year when the number is assigned. The third part is issued sequentially within each biweekly period.