Subject: IDENTIFICATION AND Date: 8/5/2005 AC No.: 45-2C 

REGISTRATION MARKING Initiated by: AIR-200 Change: 

1. PURPOSE. This advisory circular (AC) describes one way, but not the only way, to comply with 

the requirements for identifying Class I products (aircraft, aircraft engines, or propellers) with 

identification plates, and identifying aircraft with nationality and registration marks. The requirements 

are detailed in Title 14, Code of Federal Regulations (14 CFR), Part 45, Identification and Registration 

Marking. 

2. CANCELLATION. This AC cancels AC 45-2B, Identification and Registration Marking, 

dated July 16, 2003. 

3. RELATED 14 CFR SECTIONS. 

a. 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. 

b. 14 CFR Part 21, Certification Procedures for Products and Parts. Part 21 sets forth rules 

for the issue of and change to type certificates (TC), and issue of production certificates (PC), 

airworthiness certificates, and export airworthiness approvals. It also sets forth the rules governing the 

holders of these certificates and the approval of certain materials, parts, processes, and appliances. 

c. 14 CFR Part 23, Airworthiness Standards: Normal, Utility, Acrobatic, and Commuter 

Category Airplanes. Part 23 sets forth airworthiness standards for the issue of TCs and changes to 

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

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

forth airworthiness standards for the issue of TCs and changes to those certificates for transport category 

airplanes. 

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

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

rotorcraft. 

FAA Form 1320–15 (4–82) Supersedes WA Form 1320–2
AC 45-2C 8/5/2005 

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

forth airworthiness standards for the issue of TCs and changes to those certificates for transport category 

rotorcraft. 

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

airworthiness standards for the issue of TCs and changes to those certificates for manned free balloons. 

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

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

i. 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 Administrator or the 

Administrator of the Environmental Protect Agency of testing and sampling methods, analytical 

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

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

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

k. 14 CFR Part 43, Maintenance, Preventive Maintenance, Rebuilding, and Alteration. 

Part 43 sets forth rules for maintenance, preventive maintenance, rebuilding, and alteration. 

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

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

aircraft. 

n. 14 CFR Part 121, Operating Requirements: Domestic, Flag, and Supplemental 

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

o. 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. 

4. DEFINITIONS. 

a. Antique Aircraft. Paragraphs (1) through (3) below define which aircraft are considered 

antique aircraft. Paragraphs (2) and (3) below include restored or replica aircraft even if not identical 

to the original in every detail. Minor differences in configuration due to modern equipment and 

components, such as use of a tailwheel instead of a tailskid, main wheel brakes, or a modern type 

propeller, are acceptable. 

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

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8/5/2005 AC 45-2C 

(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.

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

and propellers. 

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

with fire at least as well as steel. 

d. Light-sport Aircraft. An aircraft, other than a helicopter or powered-lift that, since its original 

certification, meets the requirements as stipulated in § 1.1. 

e. 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. 

f. 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. 

g. Product. An aircraft, aircraft engine, or propeller. For further explanation refer to § 21.1(b). 

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

unique paint scheme. 

i. 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’s 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. 

5. WHO THIS AC APPLIES TO. 

a. The discussion of identification plates applies to builders of civil aircraft, aircraft engines, 

and propellers. For the purpose of this AC, the term “aircraft” includes powered parachutes and 

balloons. These builders include builders who provide valid identification plates in accordance with 

§ 21.182 for aircraft, aircraft engines, and propellers that must be displayed for an aircraft to be issued 

an airworthiness certificate. This discussion also applies to repair stations operating under 

14 CFR Part 145, Repair Stations, and air carriers operating N-numbered aircraft. 

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AC 45-2C 8/5/2005 

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

aircraft, including aircraft operated as public aircraft. 

6. RELATED READING MATERIAL. 

a. AC 20-62, Eligibility, Quality, and Identification of Aeronautical Replacement Parts. 

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. 

b. AC 20-65, U.S. Airworthiness Certificates and Authorizations for Operation of Domestic 

and Foreign Aircraft. AC 20-65 provides general information on issuing airworthiness certificates and 

special flight authorizations for certain aircraft. 

c. AC 43-17, Methods, Techniques, and Practices Acceptable to the Administrator Governing 

the Installation, Removal, or Change of Identification Data and Identification Plates. 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. 

d. AC 45-3, Installation, Removal, or Change of Identification Data and Identification Plates 

on Aircraft Engines. AC 45-3 provides information concerning the installing, removing, or changing 

identification data and identification plates on aircraft engines. 

7. IDENTIFICATION OF AIRCRAFT, AIRCRAFT ENGINES, AND PROPELLERS. 

a. Information to be Included as Identification. Each manufacturer of aircraft, aircraft engines, 

propellers, and propeller blades and hubs must display the following information a fireproof plate, by 

means of stamping, engraving, etching, or another approved method: 

(1) Builder’s name. The “builder’s name” may be the name of an individual, firm, copartnership, 

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

(2) Model designation. 

(3) Builder’s serial number. 

(4) TC number, if any. 

(5) PC number, if any. 

(6) For aircraft engines, the established rating. 

(7) The date of manufacture (that is, month (two digits)/year (four digits)) and the engine’s 

approved part 34 designation (approved designations include comply, exempt, and non-U.S.) for engines 

specified in part 34, manufactured on or after January 1, 1984. 

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8/5/2005 AC 45-2C 

b. Type and Placement of Identification Plate. The identification must be on a fireproof plate, 

placed where it is not likely to be defaced or removed during normal service, and placed on a surface not 

normally removable (for example, not on an inspection plate, removable fairing, or access cover). Refer 

to table 1 below 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 

underside of the fuselage near the tail 

surface. 

(2) 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

must be displayed on the fuselage exterior. 

For aircraft described in (2), the Federal 

Aviation Administration (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 tools or removing 

aircraft components. 

Powered parachute and 

weight-shift-control 

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 noncritical 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 follow the guidance 

in this AC; however, they may have been previously determined by the FAA to be acceptable. In all 

cases, it is important to comply with the guidance in § 45.13 that requires FAA approval for the removal 

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

follow the guidance in this AC, do not remove the identification plate without written approval from 

the FAA. 

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AC 45-2C 8/5/2005 

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

Information to be displayed as identification is described in paragraph 7a. The builder’s name is your 

name (the person who assembled the aircraft), not the name of the manufacturer who builds the same

model of aircraft. You may assign any serial number if it is clear 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, Engines, or Related Parts Produced Under a 

Licensing Agreement. You may apply the identification requirements to aircraft, engines, or related 

parts produced under a licensing agreement as follows: 

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

(2) The model designation and TC number are as identified on the original TC data sheet. 

(3) The builder’s serial number is as selected from a block of numbers, as assigned to the builder 

by the TC holder. 

(4) The PC number is as issued to the licensee. 

(5) For engines, the established rating is as shown on the TC. 

f. Removing an Identification Plate During Maintenance. You may remove an identification 

plate if necessary for performing maintenance in accordance with methods, techniques, and practices 

acceptable to the FAA. However, once you’ve completed maintenance, you must 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 Instruction for Continued Airworthiness, or other data 

acceptable to the Administrator. 

g. Acquiring a New Identification Plate from the Manufacturer. 

(1) When a new identification plate is required from a manufacturer as a result of becoming lost, 

stolen, or damaged during maintenance operations, the owner or owner’s authorized representative 

should contact the appropriate flight standards district office or manufacturing inspection district office 

to get FAA assistance and approval for obtaining the replacement. 

(2) When a new or additional identification plate is required as a result of Part 43 action (that is, 

rebuilding or alteration), when instructed by specific FAA-approved maintenance procedures contained 

in manufacturers’ manuals, letters, or bulletins, you do not need to get FAA approval as described in 

paragraph 7(g)(1). 

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8/5/2005 AC 45-2C 

h. Changing Identification Plate Information. Changing the identification data required 

by § 45.13(a) may only be done when instructed to do so to comply with specific FAA-approved 

or -accepted design data, maintenance procedures, and rebuilding or alteration procedures contained 

in manufacturers’ manuals, letters, bulletins, or other data acceptable to the FAA. 

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

same make, a new identification plate must be attached as close as physically 

possible to the original identification plate. The original identification plate must 

not be removed or altered in any manner. 

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

must have the FAA’s approval to remove, change information on, or install an identification plate for 

other than maintenance. You must not use an identification plate from a scrapped or destroyed aircraft 

or aircraft engine. You must buy identification plates from an approved source after going through the 

process described in paragraph 7(g). If you install an identification plate without the FAA’s approval, 

you are in violation of § 45.13(b), (c), and/or (e), Identification data. 

8. NATIONALITY AND REGISTRATION MARKING REQUIREMENTS FOR AIRCRAFT 

(The N-Number). The FAA Civil Aviation Registry issues the aircraft N-number. You can contact 

the Civil Aviation Registry at (405) 954-4206 to get an available N-number or at 

http://registry.faa.gov/aircraft.asp for online services. 

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

(1) You must not 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. 

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

(b) A U.S.-registered aircraft with the same external configuration as an aircraft built 

at least 30 years ago for which a special airworthiness certificate has been issued for operation as an 

exhibition aircraft, or 

(c) An amateur-built aircraft with the same external configuration as an aircraft built 

at least 30 years ago. 

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AC 45-2C 8/5/2005 

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 make sure the text 

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

c. N-Number Legibility. The N-number must be legible and be written in capital Roman style 

letters without any ornamentation. You may use shading or a border only if it makes the number 

more legible. 

(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 § 23.811(c)(7)(ii) or § 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 is 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, 

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 must 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. 

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

the N-Number, mark aircraft according to the following table.

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8/5/2005 AC 45-2C 

Table 2. Displaying the N-Number on an Aircraft 

Aircraft Type

or Category Minimum Height Location Orientation Comments 

Airships 3 inches (1) 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) 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 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. 

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, 

and each flight must 

receive prior approval. 

See details in table 3. 

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 multivertical 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

Par 8 Page 9 
AC 45-2C 8/5/2005 

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

Aircraft Type

or Category Minimum Height Location Orientation Comments 

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

vertical tail or on the outer 

surfaces of a multivertical 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 

Nonspherical

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

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, 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 it 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 rotorblades, 

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. 

Spherical 

balloons, 

powered

parachutes, 

and weightshift-control 

aircraft 

3 inches In two places diametrically 

opposite on any fuselage

structural member and near the 

maximum horizontal

circumference.

Horizontal

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 must comply with the 

requirements specified in Part 45. 

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8/5/2005 AC 45-2C 

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

your N-number. The table 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 must 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 flight standards district office 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 must 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. The term 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 and are preparing that aircraft for export and it 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 must 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. 

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 must be 12 inches high. 

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AC 45-2C 8/5/2005 

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

Circumstance Exception

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 must 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 must display full-size marks on the larger surface. 

(2) If neither authorized surface is large enough for full-size marks, you must 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 flight standards district office or manufacturing inspection district office for

assistance. 

9. HOW TO GET THE PUBLICATIONS REFERRED TO IN THIS AC. 

a. The CFR and those ACs for which a fee is charged may be obtained from the Superintendent of 

Documents at the following address. A listing of the CFR and current prices is located in AC 00-44, 

Status of Federal Aviation Regulations, and a listing of all ACs is located in AC 00.2-14, Advisory 

Circular Checklist and Status of Other FAA Publications. 

Superintendent of Documents 

P.O. Box 371954 

Pittsburgh, PA 15250-7954 

b. To be placed on the FAA’s mailing list for free ACs, contact— 

U.S. Department of Transportation 

Subsequent Distribution Office 

M-30 

Ardmore East Business Center 

3341 Q 75th Avenue 

Landover, MD 20785 

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8/5/2005 AC 45-2C 

c. You may view and print the CFR and Aircraft Certification Service and Flight Standards Service 

ACs on the FAA Web page located at http://www.airweb.faa.gov/rgl. 

/s/

Frank P. Paskiewicz 

Manager, Production and 

Airworthiness Division, AIR-200 

Par 9 Page 13