14 C.F.R. § 135.128
(a) Except as provided in this paragraph, each person on board an aircraft operated under this part shall occupy an approved seat or berth with a separate safety belt properly secured about him or her during movement on the surface, takeoff, and landing. For seaplane and float equipped rotorcraft operations during movement on the surface, the person pushing off the seaplane or rotorcraft from the dock and the person mooring the seaplane or rotorcraft at the dock are excepted from the preceding seating and safety belt requirements. A safety belt provided for the occupant of a seat may not be used by more than one person who has reached his or her second birthday. Notwithstanding the preceding requirements, a child may:
(2) Notwithstanding any other requirement of this chapter, occupy an approved child restraint system furnished by the certificate holder or one of the persons described in paragraph (a)(2)(i) of this section, provided:
(ii) Except as provided in paragraph (a)(2)(ii)(D) of this section, the approved child restraint system bears one or more labels as follows:
(B) Seats manufactured to U.S. standards on or after February 26, 1985, must bear two labels:
(1) “This child restraint system conforms to all applicable Federal motor vehicle safety standards”; and
(2) “THIS RESTRAINT IS CERTIFIED FOR USE IN MOTOR VEHICLES AND AIRCRAFT” in red lettering;
(C) Seats that do not qualify under paragraphs (a)(2)(ii)(A) and (a)(2)(ii)(B) of this section must bear a label or markings showing:
(1) That the seat was approved by a foreign government;
(2) That the seat was manufactured under the standards of the United Nations;
(3) That the seat or child restraint device furnished by the certificate holder was approved by the FAA through Type Certificate or Supplemental Type Certificate; or
(4) That the seat or child restraint device furnished by the certificate holder, or one of the persons described in paragraph (a)(2)(i) of this section, was approved by the FAA in accordance with § 21.8(d) of this chapter or Technical Standard Order C-100b, or a later version. The child restraint device manufactured by AmSafe, Inc. (CARES, Part No. 4082) and approved by the FAA in accordance with § 21.305(d) (2010 ed.) of this chapter may continue to bear a label or markings showing FAA approval in accordance with § 21.305(d) (2010 ed.) of this chapter.
(iii) The certificate holder complies with the following requirements:
(b) Except as provided in paragraph (b)(3) of this section, the following prohibitions apply to certificate holders:
(2) Except as required in paragraph (b)(1) of this section, no certificate holder may prohibit a child, if requested by the child's parent, guardian, or designated attendant, from occupying a child restraint system furnished by the child's parent, guardian, or designated attendant provided:
[Docket 26142, 57 FR 42676, Sept. 15, 1992, as amended by Amdt. 135-62, 61 FR 28422, June 4, 1996; Amdt. 135-100, 70 FR 50907, Aug. 26, 2005; Amdt. 135-106, 71 FR 40010, July 14, 2006; 71 FR 59374, Oct. 10, 2006; Amdt. 135-130, 79 FR 28812, May 20, 2014; Docket FAA-2023-2250, Amdt. 135-146, 89 FR 67850, Aug. 22, 2024]