14 C.F.R. § 29.1157 Carburetor air temperature controls.
Title 14 - Aeronautics and Space
There must be a separate carburetor air temperature control for each engine.
Title 14: Aeronautics and Space
PART 29—AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT
Subpart E—Powerplant
Powerplant Controls and Accessories
§ 29.1157 Carburetor air temperature controls.