14 C.F.R. § 29.753 Main float design.
Title 14 - Aeronautics and Space
(a) Bag floats. Each bag float must be designed to withstand— (1) The maximum pressure differential that might be developed at the maximum altitude for which certification with that float is requested; and (2) The vertical loads prescribed in §29.521(a), distributed along the length of the bag over three-quarters of its projected area. (b) Rigid floats. Each rigid float must be able to withstand the vertical, horizontal, and side loads prescribed in §29.521. An appropriate load distribution under critical conditions must be used.
Title 14: Aeronautics and Space
PART 29—AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT
Subpart D—Design and Construction
Floats and Hulls
§ 29.753 Main float design.