14 C.F.R. § 23.1327 Magnetic direction indicator.
Title 14 - Aeronautics and Space
(a) Except as provided in paragraph (b) of this section— (1) Each magnetic direction indicator must be installed so that its accuracy is not excessively affected by the airplane's vibration or magnetic fields; and (2) The compensated installation may not have a deviation in level flight, greater than ten degrees on any heading. (b) A magnetic nonstabilized direction indicator may deviate more than ten degrees due to the operation of electrically powered systems such as electrically heated windshields if either a magnetic stabilized direction indicator, which does not have a deviation in level flight greater than ten degrees on any heading, or a gyroscopic direction indicator, is installed. Deviations of a magnetic nonstabilized direction indicator of more than 10 degrees must be placarded in accordance with §23.1547(e). [Amdt. 23–20, 42 FR 36969, July 18, 1977]
Title 14: Aeronautics and Space
PART 23—AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES
Subpart F—Equipment
Instruments: Installation
§ 23.1327 Magnetic direction indicator.
