14 CFR Part 39—Airworthiness Directives
In spite of all the emphasis on proper design and certification testing, sometimes the actual day-to-day use of the aircraft causes unanticipated wear or failure to occur. When that happens, if the FAA determines that the wear or failure represents an unsafe condition and that the condition is likely to exist in other products of the same type of design, it issues an AD. Actual AD notes are not included in 14 CFR part 39, but rather are printed in the Federal Register and are linked to this part as amendments to 14 CFR part 39, section 39.13. AD notes are legally enforceable rules that apply to aircraft, aircraft engines, propellers, and appliances.
14 CFR Part 43—Maintenance, Preventive Maintenance, Rebuilding, and Alteration
This regulation represents the heart of aviation maintenance and is one of the three major regulations previously identified. The 13 rules and 6 appendices contained within 14 CFR part 43 provide the standard for maintaining all civilian aircraft currently registered in the United States. Note that 14 CFR part 43 has a significant relationship with part 91 and other parts in maintaining continued airworthiness. [Figure 2-6] A more detailed explanation of this regulation is presented later in this text.
14 CFR Part 45—Identification and Registration Marking
Title 14 of the CFR part 45 includes the requirements for the identification of aircraft, engines, propellers, certain replacement and modification parts, and the nationality and registration marking required on U.S.-registered aircraft. All type-certificated products must have the following information on a fireproof dataplate or similar approved fireproof method.
- Builder’s name
- Model designation
- Builder’s serial number
- TC number (if any)
- Production certificate number (if any)
- For aircraft engines, the established rating
- Reference to compliance or exemption to 14 CFR Part 34, Fuel Venting and Exhaust Emission Requirements for Turbine Engine Powered Airplanes
- Any other information that the FAA determines to be appropriate
Replacement and modification parts are produced in accordance with a Parts Manufacturer Approvals (PMA) (14 CFR part 21, section 21.303) and must have the following information permanently and legibly marked:
- The letters “FAA-PMA”
- The name, symbol, or trademark of the holder of the PMA
- The part number
- The name and model designation for each type certificated product it can be installed on
If a part has a specified replacement time, inspection interval, or other related procedure specification in the maintenance manual or ICA, that part must have a part number and a serial number (or the equivalent of each).
The manufacturer of a life-limited part must either provide marking instructions for that part, or state that the part cannot be marked without a compromise to its integrity. Exceptions are made for the identification of parts that are too small to be practical to mark the required data.
Nationality and registration marks (commonly known as the N-number for U.S.-registered aircraft) can vary in size, depending on the year that the aircraft was built and whether or not the aircraft has been repainted. The most common size is at least 12 inches in height. Small aircraft built at least 30 years ago, or replicas of these, or experimental exhibition or amateur-built aircraft may use letters at least 2 inches in height. Only a few aircraft are authorized to display registration markings of at least 3 inches. Note that this regulation sits directly on the vertical line in Figure 2-5 indicating that it applies to both original and recurrent airworthiness.
14 CFR Part 47—Aircraft Registration
This regulation provides the requirements for registering aircraft. It includes procedures for both owner and dealer registration of aircraft.
14 CFR Part 65—Certification: Airmen Other Than Flight Crewmembers
Pilots, flight instructors, and ground instructors are certificated under 14 CFR part 61. Flight crew other than pilots are certificated under 14 CFR part 63. However, many other people are also required to be certificated by the FAA for the U.S. aviation fleet to operate smoothly and efficiently. Title 14 CFR part 65 addresses many of those other people.
- Subpart B—Air Traffic Control Tower Operators
- Subpart C—Aircraft Dispatchers
- Subpart D—Mechanics
- Subpart E—Repairmen
- Subpart F—Parachute Riggers
A more detailed discussion of this chapter with a special emphasis on mechanics is included in Chapter 15, The Mechanic Certificate.
NOTE: SFAR 100-2. Relief for U.S. Military and Civilian Personnel who are assigned outside the United States in support of U.S. Armed Forces Operations is a good example of the specific nature and limited time frame that are part of a SFAR.
14 CFR Part 91—General Operating and Flight Rules
This is the final regulation of the three major regulations identified earlier in this chapter. Note its interaction in Figure 2-6 with other regulations visually indicating its “operational” involvement or “recurrent airworthiness.” Although it is an operational regulation that is focused toward the owner, operator, and/or pilot of the aircraft, the maintenance technician must have an awareness of this regulation. Two examples of these maintenance related issues are:
- Section 91.207—Emergency Locator Transmitters
- Paragraph (c)(2)—battery replacement interval and requirement for a logbook entry indicating the expiration date of the new battery.
- Section 91.213—Inoperative Instruments and Equipment
- Paragraph (a)(2)—a letter of authorization from the FSDO authorizing the operation of the aircraft under a Minimum Equipment List (MEL) constitutes a STC and must be carried in the aircraft during flight.
Subpart E—Maintenance, Preventive Maintenance, and Alterations (Sections 91.401 through 91.421)
This is the section of most interest to the technician. He or she must be familiar with it, because it does carry some (indirect) responsibility for the technician. Note that the 14 CFR part 91 icon in Figure 2-6 has a direct line to 14 CFR part 43. This is because section 91.403(b) states, “No person may perform maintenance, preventive maintenance, or alterations on an aircraft other than as prescribed in this subpart and other applicable regulations, including part 43 of this chapter.” A more complete discussion of this regulation, especially Subpart E—Maintenance, Preventive Maintenance, and Alterations is presented later in this chapter.
14 CFR Part 119—Certification: Air Carriers and Commercial Operators
In order to better understand the next three regulations discussed here (14 CFR parts 121, 125, and 135) a brief overview of 14 CFR part 119 is beneficial. [Figure 2-8] There are more than 50 Advisory Circulars (ACs) in the 120 series alone providing additional non-regulatory information concerning the variety of procedures involved with these operations. There are basically three different criteria that must be analyzed in order to properly determine the regulation that applies. These are:
- Is the service provided for Private Carriage or Common Carriage?
- Is the aircraft For Hire or is it Not for Hire?
- Is it a large or small aircraft?
AC 120-12, as revised, provides the following definition regarding this criterion: A carrier becomes a common carrier when it “holds itself out” to the public, or to a segment of the public, as willing to furnish transportation within the limits of its facilities to any person who wants it. There are four elements in defining a common carrier:
- A holding out of a willingness to
- Transport persons or property
- From place to place
- For compensation
This “holding out” that makes a person a common carrier can be done in many ways, and it does not matter how it is done. Signs and advertising are the most direct means of “holding out,” but are not the only ones.
Carriage for hire which does not involve “holding out” is private carriage. Private carriers for hire are sometimes called “contract carriers,” but the term is borrowed from the Interstate Commerce Act and legally inaccurate when used in connection with the Federal Aviation Act. Private carriage for hire is carriage for one or several selected customers, generally on a long-term basis. The number of contracts must not be too great; otherwise, it implies a willingness to make a contract with anybody. A carrier operating pursuant to 18 to 24 contracts has been held to be a common carrier, because it held itself out to serve the public generally to the extent of its facilities. Private carriage has been found in cases where three contracts have been the sole basis of the operator’s business.
Operations that constitute common carriage are required to be conducted under 14 CFR part 121 or 135. Private carriage may be conducted under 14 CFR part 91 or 125.
The term “for hire” is not defined in any of the FAA documents but is generally understood to mean that compensation for both direct and indirect expenses associated with the flight, as well as a profit margin for the operator, are collected from the person or persons benefiting from the flight operation.
The determination of whether the aircraft is large or small is based upon the definition provided in 14 CFR part 1. If the aircraft has maximum certificated takeoff weight of 12,500 pounds or more, it is a large aircraft. All aircraft less than 12,500 maximum certificated takeoff weight are considered to be small aircraft.
It may also help the reader understand when 14 CFR parts 121, 125, and 135 regulations apply, by taking a brief look at a list of flight operations where 14 CFR part 119 does not apply.
- Student instruction
- Nonstop sightseeing flights with less than 30 seats and less than 25 nautical miles (NM) from the departure airport
- Ferry or training flights
- Crop dusting or other agricultural operations
- Banner towing
- Aerial photography or surveying
- Fire fighting
- Powerline or pipeline patrol
- Parachute operations on nonstop flights within 25 NM from the departure airport
- Fractional ownership in accordance with 14 CFR part 91, subpart K