14 CFR § 47.31 - Application.
(3) The fee required by § 47.17.
(b) The FAA rejects an application when -
(1) Any form is not completed;
(2) The name and signature of the applicant are not the same throughout; or
(3) The applicant does not provide a legibly printed or typed name with the signature in the signature block.
(c) After compliance with paragraph (a) of this section, the applicant for registration of an aircraft last previously registered in the United States must carry the second copy of the Aircraft Registration Application in the aircraft as temporary authority to operate without registration.
(1) This temporary authority is valid for operation within the United States until the date the applicant receives the Certificate of Aircraft Registration or until the date the FAA denies the application, but in no case for more than 90 days after the date the applicant signs the application. If by 90 days after the date the applicant signs the Aircraft Registration Application, the FAA has neither issued the Certificate of Aircraft Registration nor denied the application, the Registry will issue a letter of extension that serves as authority to continue to operate the aircraft without registration while it is carried in the aircraft.
(2) This temporary authority is not available in connection with any Aircraft Registration Application received when 12 months have passed since the receipt of the first application following transfer of ownership by the last registered owner.
(3) If there is no registration number assigned at the time application for registration is made, the second copy of the Aircraft Registration Application may not be used as temporary authority to operate the aircraft.