Subpart F — Instrument and Equipment Requirements

91.501 General requirements

A person must not operate an aircraft unless—

(1) the aircraft is equipped with the type and number of instruments and equipment required by this Subpart; and

(2) the instruments and equipment installed in the aircraft comply with—

• (i) applicable specifications and airworthiness design standards; and

(3) the instruments and equipment installed in the aircraft have been installed in accordance with the aircraft manufacturer’s instructions or other equivalent instructions acceptable to the Director; and

(4) except as provided in rule 91.537, the instruments and equipment installed in the aircraft are in an operable condition.