Navigate / EASA

CS 22.1543  Instrument markings  – general

ED Decision 2003/13/RM

For each instrument:

(a)     when markings are on the cover glass of the instrument, there must be means to maintain the correct alignment of the glass cover with the face of the dial; and

(b)     each arc and line must be wide enough and located to be clearly visible to the pilot and not mask any portion of the dial.