Identification and Registration Markings
Subpart C–Nationality and Registration Marks
Sec. 45.21 General.
(a) Except as provided in Sec. 45.22, no person may operate a U.S.-
registered aircraft unless that aircraft displays nationality and
registration marks in accordance with the requirements of this section and
Secs. 45.23 through 45.33.
(b) Unless otherwise authorized by the Administrator, no person may place
on any aircraft a design, mark, or symbol that modifies or confuses the
nationality and registration marks.
(c) Aircraft nationality and registration marks must–
(1) Except as provided in paragraph (d) of this section, be painted on the
aircraft or affixed by any other means insuring a similar degree of
(2) Have no ornamentation;
(3) Contrast in color with the background; and
(4) Be legible.
(d) The aircraft nationality and registration marks may be affixed to an
aircraft with readily removable material if–
(1) It is intended for immediate delivery to a foreign purchaser;
(2) It is bearing a temporary registration number; or
(3) It is marked temporarily to meet the requirements of Sec. 45.22(c)(1)
or Sec. 45.29(h) of this part, or both.
[Doc. No. 8093, Amdt. 45-5, 33 FR 450, Jan 12, 1968, as amended by Amdt. 45-
17, 52 FR 34102, Sept. 9, 1987]
Sec. 45.22 Exhibition, antique, and other aircraft: Special rules.
(a) When display of aircraft nationality and registration marks in
accordance with Secs. 45.21 and 45.23 through 45.33 would be inconsistent
with exhibition of that aircraft, a U.S.-registered aircraft may be operated
without displaying those marks anywhere on the aircraft if:
(1) It is operated for the purpose of exhibition, including a motion
picture or television production, or an airshow;
(2) Except for practice and test fights necessary for exhibition purposes,
it is operated only at the location of the exhibition, between the exhibition
locations, and between those locations and the base of operations of the
(3) For each flight in the United States:
(i) It is operated with the prior approval of the Flight Standards District
Office, in the case of a flight 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; or
(ii) It is operated under a flight plan filed under either Sec. 91.153 or
Sec. 91.169 of this chapter describing the marks it displays, in the case of
any other flight.
(b) A small U.S.-registered aircraft built at least 30 years ago or a U.S.-
registered aircraft for which an experimental certificate has been issued
under Sec. 21.191(d) or 21.191(g) for operation as an exhibition aircraft or
as an amateur-built aircraft and which has the same external configuration as
an aircraft built at least 30 years ago may be operated without displaying
marks in accordance with Secs. 45.21 and 45.23 through 45.33 if:
(1) It displays in accordance with Sec. 45.21(c) marks at least 2 inches
high on each side of the fuselage or vertical tail surface consisting of the
Roman capital letter “N” followed by:
(i) The U.S. registration number of the aircraft; or
(ii) The symbol appropriate to the airworthiness certificate of the
aircraft (“C”, standard; “R”, restricted; “L”, limited; or “X”, experimental)
followed by the U.S. registration number of the aircraft; and
(2) It displays no other mark that begins with the letter “N” anywhere on
the aircraft, unless it is the same mark that is displayed under paragraph
(b)(1) of this section.
(c) No person may operate an aircraft under paragraph (a) or (b) of this
(1) In an ADIZ or DEWIZ described in Part 99 of this chapter unless it
temporarily bears marks in accordance with Secs. 45.21 and 45.23 through
(2) In a foreign country unless that country consents to that operation; or
(3) In any operation conducted under Part 121, 127, 133, 135, or 137 of
(d) If, due to the configuration of an aircraft, it is impossible for a
person to mark it in accordance with Secs. 45.21 and 45.23 through 45.33, he
may apply to the Administrator for a different marking procedure.
[Doc. No. 8093, Amdt. 45-5, 33 FR 450, Jan. 12, 1968, as amended by Amdt.
45-13, 46 FR 48603, Oct. 1, 1981; Amdt. 45-19, 54 FR 39291, Sept. 25, 1989;
Amdt. 45-18, 54 FR 34330, Aug. 18, 1989; Amdt. 45-21, 56 FR 65653, Dec. 17,
Sec. 45.23 Display of marks; general.
(a) Each operator of an aircraft shall display on that aircraft marks
consisting of the Roman capital letter “N” (denoting United States
registration) followed by the registration number of the aircraft. Each
suffix letter used in the marks displayed must also be a Roman capital
(b) When marks that include only the Roman capital letter “N” and the
registration number are displayed on limited or restricted category aircraft
or experimental or provisionally certificated aircraft, the operator shall
also display on that aircraft near each entrance to the cabin or cockpit, in
letters not less than 2 inches nor more than 6 inches in height, the words
“limited,” “restricted,” “experimental,” or “provisional airworthiness,” as
the case may be.
[Doc. No. 8093, Amdt. 45-5, 33 FR 450, Jan. 12, 1968, as amended by Amdt. 45-
9, 42 FR 41102, Aug. 15, 1977]
Sec. 45.25 Location of marks on fixed-wing aircraft.
(a) The operator of a fixed-wing aircraft shall display the required marks
on either the vertical tail surfaces or the sides of the fuselage, except as
provided in Sec. 45.29(f).
(b) The marks required by paragraph (a) of this section shall be displayed
(1) If displayed on the vertical tail surfaces, horizontally on both
surfaces, horizontally on both surfaces of a single vertical tail or on the
outer surfaces of a multivertical tail. However, on aircraft on which marks
at least 3 inches high may be displayed in accordance with Sec. 45.29(b)(1),
the marks may be displayed vertically on the vertical tail surfaces.
(2) If displayed on the fuselage surfaces, horizontally on both sides of
the fuselage between the trailing edge of the wing and the leading edge of
the horizontal stabilizer. However, if engine pods or other appurtenances are
located in this area and are an integral part of the fuselage side surfaces,
the operator may place the marks on those pods or appurtenances.
[Amdt. 45-9, 42 FR 41102, Aug. 15, 1977]
Sec. 45.27 Location of marks; nonfixed-wing aircraft.
(a) Rotorcraft. Each operator of a rotorcraft shall display on that
rotorcraft horizontally on both surfaces of the cabin, fuselage, boom, or
tail the marks required by Sec. 45.23.
(b) Airships. Each operator of an airship shall display on that airship the
marks required by Sec. 45.23, horizontally on–
(1) 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; and
(2) Each side of the bottom half of the vertical stabilizer.
(c) Spherical balloons. Each operator of a spherical balloon shall display
the marks required by Sec. 45.23 in two places diametrically opposite and
near the maximum horizontal circumference of that balloon.
(d) Nonspherical balloons. Each operator of a nonspherical balloon shall
display the marks required by Sec. 45.23 on each side of the balloon near its
maximum cross section and immediately above either the rigging band or the
points of attachment of the basket or cabin suspension cables.
[Doc. No. 2047, 29 FR 3223, Mar. 11, 1964, as amended by Amdt. 45-15, 48 FR
11392, Mar. 17, 1983]
Sec. 45.29 Size of marks.
(a) Except as provided in paragraph (f) of this section, each operator of
an aircraft shall display marks on the aircraft meeting the size requirements
of this section.
(b) Height. Except as provided in paragraph (h) of this part, the
nationality and registration marks must be of equal height and on–
(1) Fixed-wing aircraft, must be at least 12 inches high, except that:
(i) An aircraft displaying marks at least 2 inches high before November 1,
1981 and an aircraft manufactured after November 2, 1981, but before January
1, 1983, may display those marks until the aircraft is repainted or the marks
are repainted, restored, or changed;
(ii) Marks at least 3 inches high may be displayed on a glider;
(iii) Marks at least 3 inches high may be displayed on an aircraft for
which an experimental certificate has been issued under Sec. 21.191(d) or
21.191(g) for operating as an exhibition aircraft or as an amateur-built
aircraft when the maximum cruising speed of the aircraft does not exceed 180
knots CAS; and
(iv) Marks may be displayed on an exhibition, antique, or other aircraft in
accordance with Sec. 45.22.
(2) Airships, spherical balloons, and nonspherical balloons, must be at
least 3 inches high; and
(3) Rotorcraft, must be at least 12 inches high, except that rotorcraft
displaying before April 18, 1983, marks required by Sec. 45.29(b)(3) in
effect on April 17, 1983, and rotorcraft manufactured on or after April 18,
1983, but before December 31, 1983, may display those marks until the
aircraft is repainted or the marks are repainted, restored, or changed.
(c) Width. Characters must be two-thirds as wide as they are high, except
the number “1”, which must be one-sixth as wide as it is high, and the
letters “M” and “W” which may be as wide as they are high.
(d) Thickness. Characters must be formed by solid lines one-sixth as thick
as the character is high.
(e) Spacing. The space between each character may not be less than one-
fourth of the character width.
(f) If either one of the surfaces authorized for displaying required marks
under Sec. 45.25 is large enough for display of marks meeting the size
requirements of this section and the other is not, full-size marks shall be
placed on the larger surface. If neither surface is large enough for full-
size marks, marks as large as practicable shall be displayed on the larger of
the two surfaces. If any surface authorized to be marked by Sec. 45.27 is not
large enough for full-size marks, marks as large as practicable shall be
placed on the largest of the authorized surfaces.
(g) Uniformity. The marks required by this part for fixed-wing aircraft
must have the same height, width, thickness, and spacing on both sides of the
(h) After March 7, 1988, each operator of an aircraft penetrating an ADIZ
or DEWIZ shall display on that aircraft temporary or permanent nationality
and registration marks at least 12 inches high.
[Doc. No. 2047, 29 FR 3223, Mar. 11, 1964, as amended by Amdt. 45-2, 31 FR
9863, July 21, 1966; Amdt. 45-9, 42 FR 41102, Aug. 15, 1977; Amdt. 45-13, 46
FR 48604, Oct. 1, 1981; Amdt. 45-15, 48 FR 11392, Mar. 17, 1983; Amdt. 45-17,
52 FR 34102, Sept. 9, 1987; 52 FR 36566, Sept. 30, 1987]
Sec. 45.31 Marking of export aircraft.
A person who manufactures an aircraft in the United States for delivery
outside thereof may display on that aircraft any marks required by the State
of registry of the aircraft. However, no person may operate an aircraft so
marked within the United States, except for test and demonstration flights
for a limited period of time, or while in necessary transit to the purchaser.
Sec. 45.33 Sale of aircraft; removal of marks.
When an aircraft that is registered in the United States is sold, the
holder of the Certificate of Aircraft Registration shall remove, before its
delivery to the purchaser, all United States marks from the aircraft, unless
the purchaser is–
(a) A citizen of the United States;
(b) An individual citizen of a foreign country who is lawfully admitted for
permanent residence in the United States; or
(c) When the aircraft is to be based and primarily used in the United
States, a corporation (other than a corporation which is a citizen of the
United States) lawfully organized and doing business under the laws of the
United States or any State thereof.
[Amdt. 45-11, 44 FR 61938, Oct. 29, 1979]
14 CFR 45 * Amendmant 45-22 * Dec. 28, 1995