14 CFR § 460.15 - Human factors.
§ 460.15 Human factors.
An operator must take the precautions necessary to account for human factors that can affect a crew's ability to perform safety-critical roles, including in the following safety critical areas -
(a) Design and layout of displays and controls;
(b) Mission planning, which includes analyzing tasks and allocating functions between humans and equipment;
(c) Restraint or stowage of all individuals and objects in a vehicle; and
(d) Vehicle operation, so that the vehicle will be operated in a manner that flight crew can withstand any physical stress factors, such as acceleration, vibration, and noise.