45.21—General.
(a)
Except as provided in § 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 §§ 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.
(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 permanence;
(d)
The aircraft nationality and registration marks may be affixed to an aircraft with readily removable material if—
(3)
It is marked temporarily to meet the requirements of § 45.22(c)(1) or § 45.29(h) of this part, or both.