(a) Each magnetic direction indicator must be installed so that its accuracy is not excessively affected by the airplane's vibration or magnetic fields.
(b) The compensated installation may not have a deviation, in level flight, greater than 10 degrees on any heading.
source: Docket No. 5066, 29 FR 18291, Dec. 24, 1964, unless otherwise noted.
cite as: 14 CFR 25.1327