14 CFR 121.311(b) Except as provided in this paragraph, each person on board an airplane operated under this part shall occupy an approved seat or berth with a

14 CFR 121.311(b) Except as provided in this paragraph, each person on board an airplane 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. https://www.ecfr.gov/current/title-14/part-121/section-121.311#p-121.311(b) https://www.ecfr.gov/current/title-14/part-121/section-121.3...