Heading indicator Directional Gyro heading indicator en http://en.wikipedia.org/wiki/Heading_indicator Heading indicator English Directional Gyro English Heading indicator English Heading indicator Heading indicator Heading indicator Heading indicator w:Heading indicator http://en.wikipedia.org/wiki/Heading_indicator Heading indicator (HI) Heading indicator English ژیروسکوپی Heading indicator Heading indicator Heading indicator (HI) Heading indicator directional gyroscope Directional Gyro (DG) Heading indicator