Each of the four preceding 14 CFR regulations require that the engine used in the aircraft must be type certificated. Title 14 CFR part 33 details the requirements for both reciprocating and turbine style aircraft engines. It not only specifies the design and construction requirements, but also the block test requirements that subject the engine to extremely demanding testing in order to prove its capability of enduring the stresses of powering the aircraft.

Just as each engine used on an aircraft must have a TC, the propeller must also be type certificated. This part is arranged the same way that 14 CFR part 33 is, in that subpart B specifies design and construction while subpart C covers tests and inspections.

Since regulations change over the years, not every aircraft presently flying meets the current design regulations as printed this year. When regulations are revised, they are printed in the Federal Register and released with an amendment number that ties them to the regulation being revised. Aircraft are required to meet only the specifications in force at the time the aircraft is built. Note: The preceding statement does not apply to the mandatory requirements imposed by Airworthiness Directives (AD), as these usually have a compliance date included in the AD note.

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.

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 handbook.

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.

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:

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 cklist.

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.