Advisory

Circular

Subject: Identification and Registration 

Marking

Date: DATE OF FINAL 

RULE

Initiated by: AIR–112

AC No: 45-2E

1. Purpose.

a. This advisory circular (AC) provides information about Title 14, Code of Federal

Regulations (14 CFR), part 45, Identification and Registration Marking. This AC is not 

mandatory and does not constitute a regulation. This AC describes an acceptable means, but not 

the only means, to comply with the requirements for marking aircraft and aircraft engines with 

identification plates, marking of propellers, and marking aircraft with nationality and registration 

marks. However, if you use the means described in the AC, you must follow it in all important 

respects.

b. A list of other related sections of 14 CFR and related publications, and definitions 

pertinent to this AC are located in the appendixes to this AC.

2. Audience. 

a. This AC affects—

(1) Builders of civil aircraft, aircraft engines, and propellers. 

(2) All production approval holders (PAH), including persons who export their products 

to the United States under the provisions of an agreement between the United States and another 

country or jurisdiction. 

(3) Repair stations operating under 14 CFR part 145 and air carriers operating Nnumbered aircraft (see appendix C to this AC for the definition of “N-number”). 

b. The discussion of nationality and registration marks applies to owners and operators of 

civil aircraft, including aircraft operated as public aircraft.

c. The discussion of marking requirements applies to all PAHs, and manufacturers producing 

under type certificate (TC) only.
XX/XX/XXXX AC 45-2E

2

3. Effective Date. This AC is effective (INSERT EFFECTIVE DATE OF FINAL RULE) the 

day Changes to Production Certificates and Approvals; Final Rule is published in the

Federal Register under docket number FAA-2013-0933.

4. Explanation of Changes. This revision reflects changes made to 14 CFR § 45.11(c) which—

a. Removes the requirement that fixed-pitch wooden propellers be marked using an 

approved fireproof method. 

b. Revises language to clarify that an identification plate is not required for propellers, 

propeller blades, or propeller hubs, but is an acceptable method for fireproof part marking.

c. Incorporates the current AC formatting policy.

5. Cancellation. This AC cancels, as of its effective date, AC 45-2D. 

6. Identification of Aircraft, Aircraft Engines, and Propellers. 

a. Information to be Included as Identification. Manufacturers of aircraft or aircraft 

engines are required to display the following information using a fireproof plate. The following 

information must also be displayed on propellers, propeller blades, and propeller hubs, but can be 

done so by means of plate, stamping, engraving, etching, or another approved method. Except 

for a fixed-pitch wooden propeller, the marking must be accomplished using an approved 

fireproof method: 

(1) The builder’s name, which may be the name of an individual, firm, co-partnership, 

corporation, company, association, or joint-stock association. 

(2) Model designation.

(3) Builder’s serial number. 

(4) TC number, if any. 

(5) Production certificate (PC) number, if any. 

(6) For aircraft engines, the established rating. 

(7) For aircraft engines, the date of manufacture, that is, month (two digits)/

year (four digits). 

(8) For aircraft engines, the engine’s approved 14 CFR part 34 designation. (Part 34 

discusses fuel venting and exhaust emission requirements for turbine engine-powered airplanes.) 

Approved designations include comply, exempt, and non-U.S. for engines specified in part 34, 

manufactured on or after January 1, 1984. 

b. Type and Placement of Identification Plate. The identification is required to be located 

on a fireproof plate, placed on a surface where it is not likely to be defaced or removed during 

Comment [RWC1]: This paragraph needs to be 

rewritten .... Propellers, propeller blades and hubs 

do not require fireproof plates. The data can be 

placed directly onto the product or article. Also, the 

fixed-pitch wooden propeller is not excluded from 

the applying the information from 45.13 onto the 

propeller ... they are only exempted from the 

fireproof method requirement.
XX/XX/XXXX AC 45-2E

3

normal service. The identification cannot be placed on an inspection plate, removable fairing, or 

access cover. Refer to Table 1 for additional identification plate location information.

Table 1. Identification Plate Location 

Aircraft or 

Equipment 

Location Comments 

Aircraft (to 

include 

light-sport 

aircraft), except 

for balloons.

(1) Outside the aircraft so that it is legible 

from the ground, either just behind and next to 

the rear-most entrance door or on the side or 

bottom of the fuselage near the tail surface. 

(2) The following aircraft are excluded from 

the requirement to display identification 

information on the aircraft exterior: Aircraft 

operated under part 121; commuter aircraft;

gliders that operate are under an Federal 

Aviation Administration (FAA)-approved 

continuous airworthiness maintenance 

program; and all aircraft manufactured for 

export.

(3) If the aircraft was manufactured before 

March 7, 1988, some other interior or exterior 

location near an entrance, so that it is legible 

from the ground, either just behind and next to 

the rear-most entrance door or on the 

underside of the fuselage near the tail surface. 

The model and serial numbers also is required 

to be displayed on the fuselage exterior. 

The FAA accepts locations where you have 

to open a door or remove items, such as 

baggage or carry-on items, to make the plate 

visible. The plate may be covered or 

enclosed if it can be uncovered without 

using tools or removing aircraft components. 

Powered 

parachute and 

weight-shiftcontrol aircraft 

On the fuselage exterior so that it is legible 

from the ground. 

Balloons On the balloon envelope and where it is 

legible to the operator when the balloon is 

inflated. 

Mark the basket and heater assembly with the

manufacturer’s name, part number (or 

equivalent), and serial number (or 

equivalent). 

Engines At an accessible place where it will not likely 

be lost or destroyed in an accident. 

Propellers, 

propeller blades, 

or propeller hubs 

On a non-critical surface. If possible, where it 

is visible without disassembly of the propeller. 

c. Manufacturer-installed identification plate. 

(1) The FAA has previously approved factory-installed identification plates on the 

fuselage exterior near the tail surface on some models. These models do not need an 

additional plate. 

(2) The manufacturer-installed identification plate on some models may not conform to 

the guidance in this AC; however, the FAA may have previously determined the identification 
XX/XX/XXXX AC 45-2E

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plate to be acceptable. In all cases, it is important that the manufacturer comply with the

guidance in § 45.13, Identification data, that requires FAA approval for the removal of an 

identification plate, except as required during maintenance operations. If those models do not 

conform to the guidance in this AC, do not remove the identification plate without written 

approval from the FAA. 

d. Identification Plate Requirements for Aircraft Built from Spare or Surplus Parts. 

Information to be displayed as identification is described in paragraph 6a. In addition, the 

following guidelines should be followed:

(1) You should use the builder’s name as your name (the person who assembled the 

aircraft), not the name of the manufacturer who builds the same model of aircraft. 

(2) You may assign any serial number if it is clear that the manufacturer who builds the 

same model of aircraft did not assign an identical number. You should add a letter prefix or 

suffix, such as your name or initials, to the serial number to provide positive identification. 

e. Identification Plate Requirements for Aircraft, Aircraft Engines, or Propellers 

Produced Under a Design Data Licensing Agreement Program. The identification 

requirements for aircraft and aircraft engines produced under a design data licensing program (as 

applicable) are as follows (see § 45.13). The identification requirements also pertain to 

propellers, propeller blades, and propeller hubs if an identification plate will be used as the 

method for fireproof marking.

(1) The builder’s name is the specific name of the licensee (as shown on the 

licensee’s PC).

(2) The model designation is the model identified on the associated TC Data Sheet 

(TCDS).

(3) The builder’s serial number is the serial number(s) dedicated for licensee use as 

assigned by the TC holder on the associated TCDS.

(4) The TC number is the number identified on the associated TCDS and is used to 

determine conformity to type design requirements.

(5) The PC number is the number listed on the licensee’s PC.

(6) For aircraft engines, the established rating is shown on the TCDS.

(7) For aircraft engines manufactured after January 1, 1984, the following information is 

also to be included:

(a) The date of manufacture as defined in § 34.1, Definitions, and

(b) The status of compliance to applicable exhaust emission provisions, as approved 

by the Administrator (for example, in compliance, exempt, or non-U.S., as appropriate).

Comment [RWC2]: Propellers are not required 

to have an identification plate.
XX/XX/XXXX AC 45-2E

5

(8) For products manufactured under a design data licensing agreement between an 

FAA TC and PC holder, the following information is required on the identification plates: 

Manufactured by (insert the PC holder’s name) under a licensing agreement 

program with (insert the TC holder’s name) (See § 45.13(a)(8).). 

NOTE: The FAA requires that only the information above be included on the 

identification plates for all products manufactured under a licensing agreement 

program. However, the FAA permits a company/corporate logo or registered 

trademark to be included (after review and approval by the FAA) on the 

identification plates if desired by the manufacturer. Aircraft, aircraft engine, and if 

applicable, propeller identification plates should be included as part of the 

product’s approved design data and are usually defined in an engineering drawing 

describing such items as material, size, required information entries, and mounting 

location. 

f. Removing an Identification Plate During Maintenance. If necessary, you may remove 

an identification plate for performing maintenance in accordance with methods, techniques, and 

practices acceptable to the FAA. However, once you complete the maintenance, you are required 

to reinstall the identification plate on the same product—

(1) At the same location, using the original means of attachment; or 

(2) In another location and/or by using another means of attachment in accordance with 

FAA-approved technical data, including Instructions for Continued Airworthiness.

g. Acquiring a New Identification Plate from the Manufacturer. 

(1) The owner or owner’s authorized representative is required to obtain a new 

identification plate from the manufacturer when an identification plate is lost, stolen, or damaged 

during maintenance operations. The owner or owner’s authorized representative should contact 

the appropriate Flight Standards District Office (FSDO) or Manufacturing Inspection District 

Office (MIDO) to get FAA assistance and approval for obtaining the replacement. 

(2) You do not need to get FAA approval as described in paragraph 6g(1) when—

(a) A new or additional identification plate is required as a result of rebuilding or 

alteration action under 14 CFR part 43, Maintenance, Preventive Maintenance, Rebuilding, and 

Alteration, and 

(b) Instructed by specific FAA-approved maintenance procedures contained in 

manufacturers’ manuals, letters, or bulletins.

h. Changing Identification Plate Information. You may change the identification data 

required by § 45.13(a) only when such changes comply with specific FAA-approved or -accepted 

data (for example, design data, maintenance procedures, and rebuilding or alteration procedures 

contained in manufacturers’ manuals, letters, bulletins).

Comment [RWC3]: Propellers are not required 

to have an identification plate.
XX/XX/XXXX AC 45-2E

6

NOTE: When an aircraft has been modified to conform to another model of 

the same make, a new identification plate is required to be attached as close 

as physically possible to the original identification plate. The original 

identification plate is not to be removed or altered in any manner. 

i. Acquiring an Identification Plate from Other Than the Manufacturer. 

(1) You are required to have the FAA’s approval to remove, change information on, or 

install an identification plate for other than maintenance. 

(2) You are required not to use an identification plate from a scrapped or destroyed 

aircraft or aircraft engine. 

(3) You are required to buy identification plates from an approved source after going 

through the process described in paragraph 6g. 

(4) If you install an identification plate without the FAA’s approval, you are in violation 

of § 45.13(b), (c), and/or (e). 

7. Nationality and Registration Marking Requirements for Aircraft (the N-Number). The 

FAA Civil Aviation Registry issues the aircraft N-number. To get an available N-number, you 

may contact the Civil Aviation Registry at (405) 954-4206 or use the online services at 

http://www.faa.gov/licenses_certificates/aircraft_certification/aircraft_registry/n_numbers/.

a. Placing Other Text or Graphics Between the Two Parts of an N-Number. 

(1) You are not to place any text or graphic between any of the letters or numbers in the 

N-number unless the aircraft is an antique aircraft. 

(2) You may insert the symbol (“C,” standard; “R,” restricted; “L,” limited; or “X,” 

experimental or provisionally certificated) appropriate to the airworthiness certificate of the 

three types of aircraft listed below. The symbol may be placed between the nationality 

designation and the registration number, for example, NX1234. 

b. Placing Text or Graphics Elsewhere on the Aircraft. You may put text or graphics on 

areas of the aircraft other than those reserved for the N-number. Ask a local FAA inspector to 

ensure that the text or graphic does not impede or degrade the legibility of the N-number. 

c. N-Number Legibility. The N-number is required to be legible and written in capital 

Roman style letters without any ornamentation. You may use shading or a border only if it 

makes the number more legible. Use the following guidelines:
XX/XX/XXXX AC 45-2E

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(1) Make sure the color contrasts sufficiently with the color of the fuselage to make it easy 

to read. Be especially careful when the background is highly decorated, as in checkering. 

Consider applying the requirements of 14 CFR § 23.811(c)(7)(ii) or 14 CFR § 25.811(f)(2), 

Emergency exit marking, as a test of whether the color of the N-number contrasts sufficiently 

with the background. 

(2) Check the reflectance of external markings. Using electro-optical instruments or 

photometer card sets is an acceptable means of verifying reflectance, but these are not required to 

establish reflectance. The FAA considers a 12-inch number legible if you can read it from 

500 feet away, in a horizontal line, and perpendicular to the side of the aircraft during daylight 

hours, without using an optical aid such as binoculars. 

(3) If you question whether an N-number is legible, either because of color or reflectance, 

check with your local FAA inspector. 

d. Applying the N-Number on Aircraft. 

(1) You are required to apply the N-number in a permanent way. Use paint that needs 

thinners or strippers to remove it, or use decals. Do not use tape that can be peeled off and do 

not use water-soluble paint, such as poster paint. 

(2) You may use removable materials if the aircraft—

(a) Has a temporary nationality designation and registration number. 

(b) Is intended for immediate delivery to a non-U.S. purchaser. 

(c) Will be flown into an Air Defense Identification Zone or a Distant Early Warning 

Identification Zone and does not have permanent markings. 
XX/XX/XXXX AC 45-2E

8

e. Displaying the N-Number on Aircraft. Except as provided in Table 3, Exceptions to 

Displaying the N-Number, mark aircraft in accordance with Table 2 below. 

Table 2. Displaying the N-Number on an Aircraft

Aircraft Type or 

Category

Minimum 

Height Location Orientation Comments

Airships 3 inches (1) On the upper surface of 

the right horizontal stabilizer 

and on the under surface of 

the left horizontal stabilizer,

with the top of the marks 

toward the leading edge of 

each stabilizer, or 

(2) On each side of the 

bottom half of the vertical 

stabilizer. 

Horizontal 

Antique aircraft 2 inches (1) On both sides of the 

fuselage between the trailing 

edge of the wing and the 

leading edge of the horizontal 

stabilizer, or 

(2) On the vertical tail 

surface, either over or under 

the horizontal stabilizer. 

Horizontal or 

Vertical

You may display the 

category symbol between the 

nationality designation and 

the registration number. You 

may not display any other 

mark beginning with the 

nationality designation 

elsewhere on the aircraft. 

Antique aircraft registered as 

N-numbered aircraft may 

display markings as they 

were applied at the time of 

initial certification.

Experimental 

aircraft—

exhibition, 

amateur-built, and 

light-sport aircraft 

with a maximum 

cruising speed of 

180 knots or less 

3 inches 

(with 

exceptions 

as shown in 

Table 3) 

(1) On both sides of the 

fuselage between the trailing 

edge of the wing and the 

leading edge of the horizontal 

stabilizer, or 

(2) On both sides of the 

vertical tail surface. 

Horizontal 

(with 

exceptions as 

shown in 

Table 3). 

No markings are required on 

certain exhibition aircraft, if 

the registration marks would 

be inconsistent with 

exhibition of that aircraft. 

Operations without markings 

are limited to those 

operations and procedures 

listed in § 45.22, Exhibition, 

antique, and other aircraft: 

Special rules. Each flight is 

required to receive prior 

approval. See details in 

Table 3. 
XX/XX/XXXX AC 45-2E

9

Table 2. Displaying the N-Number on an Aircraft (continued)

Aircraft Type 

or Category

Minimum 

Height Location Orientation Comments

Fixed-wing 

aircraft 

12 inches 

(with 

exceptions 

as shown in 

Table 3) 

(1) On both surfaces of a single 

vertical tail or on the outer 

surfaces of a multi-vertical tail, or 

(2) On the fuselage surfaces, on 

both sides of the fuselage between 

the trailing edge of the wing and 

the leading edge of the horizontal 

stabilizer. If engine pods or other 

equipment are located in this area 

and are an integral part of the 

fuselage side surfaces, you may 

place the marks on those pods or 

equipment. 

Horizontal 

Gliders 3 inches (1) On both surfaces of a single 

vertical tail or on the outer 

surfaces of a multi-vertical tail, or 

(2) On the fuselage surfaces, on 

both sides of the fuselage between 

the trailing edge of the wing and 

the leading edge of the horizontal 

stabilizer. 

Horizontal 

or Vertical 

Horizontal 

Non-spherical 

balloons 

3 inches On each side near its maximum 

cross-section, and immediately 

above either the rigging band or 

the points of attachment of the 

basket or cabin suspension cables. 

Horizontal 
XX/XX/XXXX AC 45-2E

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Table 2. Displaying the N-Number on an Aircraft (continued)

Aircraft Type 

or Category

Minimum 

Height Location Orientation Comments

Spherical 

balloons, 

powered 

parachutes, and 

weight-shiftcontrol aircraft

3 inches In two places diametrically 

opposite on any fuselage 

structural member and near the 

maximum horizontal 

circumference.

Horizontal

Rotorcraft 12 inches 

(with 

exceptions 

as shown in 

Table 3) 

Both external side surfaces: 

Engine nacelles, roof structure, 

and fixed surfaces visible from 

500 feet away, in a horizontal 

line. Also, perpendicular to the 

side of the aircraft during daylight 

hours, without using an optical aid 

such as binoculars.

Allowable locations include—

(1) The cabin or fuselage, 

including the roof structure, and 

hinge or sliding doors, but not 

where the N-number will be 

covered by doors that can be 

opened in flight. The appropriate 

controls should be in place to 

prevent the loss of the required 

identification when the door 

panels are replaced. 

(2) Boom. Side surfaces. 

(3) Tail. Outboard surfaces of 

the vertical tail(s), if the rotor 

blade, guards, or other equipment 

do not obstruct the display. 

Horizontal If none of the approved 

surfaces are large enough for 

12-inch letters, make them as 

large as practicable and put 

them on the largest of the 

authorized surfaces. 

f. N-Numbers as Part of the Type Design of an Aircraft. N-numbers are not design 

requirements. The FAA does not approve them as part of the type design, although they may 

appear in type design drawings and data as points of reference. The N-number is required to

comply with the requirements specified in part 45.
XX/XX/XXXX AC 45-2E

11

g. Exceptions to Displaying the N-Number. There are exceptions to how and where you 

display your N-number. Table 3 below lists the circumstances and explains the exceptions. 

Table 3. Exceptions to Displaying the N-Number

Circumstance Exception 

Displaying an N-number on an 

exhibition aircraft 

If displaying the N-number is inconsistent with the purpose of the exhibition 

(for example, during the taping of a motion picture or television production, 

or during an airshow), you may operate the aircraft without displaying the 

N-number. 

(1) You may operate unmarked exhibition aircraft only—

(a) For practice and test flights necessary for exhibition, 

(b) At the exhibition, 

(c) Between exhibition locations, or 

(d) Between those locations and the base of operations of the aircraft. 

(2) For each flight in the United States, you are required to either—

(a) File a flight plan under 14 CFR part 91, General Operating and Flight 

Rules, § 91.153 or § 91.169, or 

(b) Get prior approval from the FSDO if the flight is within the lateral 

boundaries of the surface areas of class B, class C, class D, or class E airspace 

designated for the takeoff airport; or within 4.4 nautical miles of that airport if 

it is within class G airspace. 

Displaying an N-number on a 

limited or restricted category 

aircraft or experimental or 

provisionally certificated aircraft 

Unless you’ve included the aircraft’s category letter in the N-number between 

the nationality designation and the registration number (for example, NR1234

for a restricted aircraft), the aircraft is required to display near each entrance 

to the cabin or cockpit the term “limited,” “restricted,” “experimental,” or 

“provisional airworthiness,” as appropriate. The term should be visible to 

anyone entering the aircraft and should be 2 to 6 inches high. 

Displaying an N-number on an 

aircraft with multiple airworthiness 

certificates 

You may use a removable category placard for the term “limited,” 

“restricted,” “experimental,” and “provisional airworthiness,” as appropriate. 

The term should be 2 to 6 inches high. 

Displaying nationality and 

registration marks on an aircraft 

intended for export 

(1) If you manufactured an aircraft, are preparing that aircraft for export, and 

the aircraft is registered in the United States, you may mark the aircraft with 

the nationality and registration marks assigned by the country you will be 

delivering it to. You may operate the aircraft in the United States with that 

number to transport it to the purchaser or, for a limited time, for test or 

demonstration flights. 

(2) If the aircraft is already registered in the importing country, you may not 

display an N-number during operations in the United States. You are 

required to display the nationality and registration marks of the importing 

country and obtain a special flight authorization under § 91.715, Special flight 

authorizations for foreign civil aircraft, to operate the aircraft in the 

United States. 

(3) You may not display the marks of the United States and those of other 

countries at the same time. This could cause confusion as to the correct 

marks. 
XX/XX/XXXX AC 45-2E

12

Table 3. Exceptions to Displaying the N-Number (continued)

Circumstance Exception 

Displaying a minimum-height 

N-number on a fixed-wing aircraft 

On an aircraft displaying 2-inch marks before November 1, 1981, and on 

aircraft manufactured between November 2, 1981, and January 1, 1983, you 

may display those marks until the aircraft is repainted or the marks are 

repainted, restored, or changed. Once the aircraft is repainted or the marks 

are repainted, restored, or changed, the N-number is required to be 12 inches 

high. 

Displaying a minimum-height 

N-number on a rotorcraft 

On a rotorcraft manufactured and marked before December 21, 1983, you 

may display those marks until the rotorcraft is repainted or the marks are 

repainted, restored, or changed. Once the rotorcraft is repainted or the marks 

are repainted, restored, or changed, the N-number is required to be 12 inches 

high. 

Displaying a minimum-height 

N-number on exhibition, 

amateur-built, or light-sport aircraft 

with a maximum cruising speed of 

180 knots or less 

(1) If you display N-numbers on each side of the vertical tail surface, the 

minimum height for a newly painted mark is 3 inches, except for antique 

aircraft, or aircraft with the same external configuration as an aircraft built at 

least 30 years ago. Details are found in § 45.22(b)(1), Exhibition, antique, 

and other aircraft: Special rules. 

(2) If you display N-numbers vertically, follow the requirements of 

§ 45.25(b)(1), Location of marks on fixed-wing aircraft. 

Displaying required marks on a 

surface not large enough to meet 

size requirements 

(1) If one of the surfaces authorized for displaying required marks is large 

enough to display marks meeting the size requirement, and the other 

authorized surface is not large enough, you are required to display full-size 

marks on the larger surface. 

(2) If neither authorized surface is large enough for full-size marks, you are 

required to display marks as large as practicable on the largest authorized 

surface. 

Displaying an N-number on an 

aircraft, but not as specified in 

this AC 

You may ask the FAA for authority to display the number in some other way. 

Contact your local FSDO or MIDO for assistance. 

8. Where to Find This AC. You can find this AC at 

http://www.faa.gov/regulations_policies/advisory_circulars/.

David W. Hempe

Manager

Design, Manufacturing, and Airworthiness Division, AIR-100
XX/X/XXXX AC 45-2E

Appendix A

A–1

Appendix A. Related Sections of 14 CFR

14 CFR part 1, Definitions and Abbreviations. Part 1 defines the words and terms used in 

subchapters A through K of chapter 1 of 14 CFR. 

14 CFR part 21, Certification Procedures for Products, Articles, and Parts. Part 21 sets 

forth rules for the issue of and change to TCs, and issuance of PCs, airworthiness certificates, and

export airworthiness approvals. It also sets forth the rules governing the holders of these 

certificates and the approval of certain products and articles.

14 CFR part 23, Airworthiness Standards: Normal, Utility, Acrobatic, and Commuter 

Category Airplanes. Part 23 sets forth airworthiness standards for the issuance of TCs and 

changes to those certificates for normal, utility, acrobatic, and commuter category airplanes. 

14 CFR part 25, Airworthiness Standards: Transport Category Airplanes. Part 25 sets 

forth airworthiness standards for the issuance of TCs and changes to those certificates for 

transport category airplanes. 

14 CFR part 27, Airworthiness Standards: Normal Category Rotorcraft. Part 27 sets forth 

the airworthiness standards for issuance of TCs and changes to those certificates for normal 

category rotorcraft. 

14 CFR part 29, Airworthiness Standards: Transport Category Rotorcraft. Part 29 sets 

forth airworthiness standards for the issuance of TCs and changes to those certificates for 

transport category rotorcraft. 

14 CFR part 31, Airworthiness Standards: Manned Free Balloons. Part 31 sets forth 

airworthiness standards for the issuance of TCs and changes to those certificates for manned free 

balloons. 

14 CFR part 33, Airworthiness Standards: Aircraft Engines. Part 33 sets forth airworthiness 

standards for the issuance of TCs and changes to those certificates for aircraft engines. 

14 CFR part 34, Fuel Venting and Exhaust Emission Requirements for Turbine Engine 

Powered Airplanes. Part 34 provides for the approval or acceptance by the FAA or the 

Administrator of the Environmental Protection Agency of testing and sampling methods, 

analytical techniques, and related equipment not identical to those specified in part 34. 

14 CFR part 35, Airworthiness Standards: Propellers. Part 35 sets forth airworthiness 

standards for the issuance of TCs and changes to those certificates for propellers. 

14 CFR part 43, Maintenance, Preventive Maintenance, Rebuilding, and Alteration. 

Part 43 sets forth rules for maintenance, preventive maintenance, rebuilding, and alteration. 
XX/XX/XXXX AC 45-2E

Appendix A

A–2

14 CFR part 45, Identification and Registration Marking. Part 45 sets forth rules for the 

display of nationality and registration marks; display of special airworthiness classification 

marks; identification plates for aircraft, aircraft engines, and propellers; and identification of 

certain replacement and critical aircraft parts and components. 

14 CFR part 47, Aircraft Registration. Part 47 sets forth the requirements for registering 

aircraft. 

14 CFR part 121, Operating Requirements: Domestic, Flag, and Supplemental Operations. 

Part 121 sets forth operating requirements for domestic, flag, and supplemental operations. 

14 CFR part 135, Operating Requirements: Commuter and On Demand Operations and 

Rules Governing Persons On Board Such Aircraft. Part 135 sets forth operating requirements 

for commuter and on-demand operations and rules governing persons aboard such aircraft.
XX/XX/XXXX AC 45-2E

Appendix B

B–1

Appendix B. Related Reference Material

U.S. Department of Transportation, Federal Aviation Administration, AC 20-62, Eligibility, 

Quality, and Identification of Aeronautical Replacement Parts, current edition. AC 20-62 

provides information on how to determine the quality, eligibility, and traceability of aeronautical 

parts and materials intended for installation on U.S. type-certificated products. 

U.S. Department of Transportation, Federal Aviation Administration, AC 20-65, 

U.S. Airworthiness Certificates and Authorizations for Operation of Domestic and Foreign 

Aircraft, current edition. AC 20-65 provides general information on issuing airworthiness 

certificates and special flight authorizations for certain aircraft. 

U.S. Department of Transportation, Federal Aviation Administration, AC 43-17, Methods, 

Techniques, and Practices Acceptable to the Administrator Governing the Installation, 

Removal, or Change of Identification Data and Identification Plates, current edition. 

AC 43-17 provides information concerning installing, removing, or changing identification data 

and identification plates on aircraft, aircraft engines, propellers, and propeller blades and hubs. 

U.S. Department of Transportation, Federal Aviation Administration, AC 45-3, 

Installation, Removal, or Change of Identification Data and Identification Plates on Aircraft 

Engines, current edition. AC 45-3 provides information concerning installing, removing, or 

changing identification data and identification plates on aircraft engines. 

10/16/2009 AC 45-2E

Appendix C

C–1

Appendix C. Definitions

Antique aircraft. Paragraphs (1) through (3) below define antique aircraft. Paragraphs (2) 

and (3) below include restored or replica aircraft even if the aircraft is not identical to the original 

in every detail. Minor differences in configuration due to modern equipment and components are 

acceptable. Examples of such differences include using a tail wheel instead of a tailskid, main 

wheel brakes, or a modern type propeller.

(1) A U.S.-registered aircraft built at least 30 years ago, 

(2) A U.S.-registered aircraft possessing a special airworthiness certificate in the 

experimental category for the purpose of exhibition with the same external configuration as an 

aircraft built at least 30 years ago, or 

(3) A U.S.-registered aircraft possessing a special airworthiness certificate in the 

experimental category for the purpose of operating an amateur-built aircraft with the same 

external configuration as an aircraft built at least 30 years ago.

Article. A material, part, component, process, or appliance.

Builder. Includes amateur-builders and manufacturers of aircraft, aircraft engines, 

and propellers. 

Fireproof. As stated in § 1.1, General definitions, the capacity to withstand the heat associated 

with fire at least as well as steel. 

Light-sport aircraft. A category of simple, very basic, small lightweight, low performance 

aircraft. It is an aircraft other than a helicopter or powered-lift. Also see definition in § 1.1. 

N-number. An identifier unique to each aircraft. The letter prefix designates the country where 

the aircraft is registered. The United States is “N,” which is why this number is commonly called 

the “N-number.” The rest of the number is the aircraft’s individual registration number, for

example, N1234, or a combination of numbers and letter suffixes as described in § 47.15(b), 

Identification number. 

Powered parachute. A powered aircraft comprised of a flexible or semi-rigid wing connected 

to a fuselage so that the wing is not in position for flight until the aircraft is in motion. The

fuselage of a powered parachute contains the aircraft engine and a seat for each occupant, and is 

attached to the aircraft’s landing gear. 

Product. An aircraft, aircraft engine, or propeller. 

Text or graphic. Includes any company name, decoration, emblem, symbol, trademark, or 

unique paint scheme. 
XX/XX/XXXX AC 45-2E

Appendix C

C–2

Weight-shift-control aircraft. A powered aircraft with a framed pivoting wing and a fuselage 

controllable only in pitch and roll by the pilot’s ability to change the aircraft center of gravity 

with respect to the wing. Flight control of the aircraft depends on the wing’s ability to flexibly 

deform rather than the use of control surfaces.