14 C.F.R. § 27.1381 Instrument lights.
Title 14 - Aeronautics and Space
The instrument lights must— (a) Make each instrument, switch, and other devices for which they are provided easily readable; and (b) Be installed so that— (1) Their direct rays are shielded from the pilot's eyes; and (2) No objectionable reflections are visible to the pilot.
Title 14: Aeronautics and Space
PART 27—AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT
Subpart F—Equipment
Lights
§ 27.1381 Instrument lights.