14 C.F.R. § 47.35
(a) A person who is the owner of an aircraft last previously registered under 49 U.S.C. Sections 44101-44104, or under other law of the United States, may register it under this part if he complies with §§ 47.3, 47.7, 47.8, 47.9, 47.11, 47.13, 47.15, and 47.17, as applicable and submits with his Aircraft Registration Application, AC Form 8050-1 an Aircraft Bill of Sale, AC Form 8050-2, signed by the seller or an equivalent conveyance, or other evidence of ownership authorized by § 47.11.
[Doc. No. 7190, 31 FR 4495, Mar. 17, 1966, as amended by Amdt. 47-16, 37 FR 25487, Dec. 1, 1972; Amdt. 47-20, 44 FR 61940, Oct. 29, 1979; Amdt. 47-27, 70 FR 245, Jan. 3, 2005; 73 FR 55722, Sept. 26, 2008; Amdt. 47-29, 75 FR 41979, July 20, 2010]