To Non-Java ALLSTAR Network Website

                                                                                                                                                                        JAVA-capable browser required for graphic-based menus (Exploer 3.0 or Netscape 2.0 or greater)

Please let me remind all of you--this material is copyrighted.  Though partially funded by NASA, it is still a private site.  Therefore, before using our materials in any form, electronic or otherwise, you need to ask permission.
There are two ways to browse the site: (1) use the search button above to find specific materials using keywords; or,
(2) go to specific headings like history, principles or careers at specific levels above and click on the button.
Teachers may go directly to the Teachers' Guide from the For Teachers button above or site browse as in (1) and (2).

FAQnewred.gif (906 bytes)           

Navigation Systems - Level 3

Radio Magnetic Indicator

baj2_ln.gif (315 bytes)

Many radio magnetic indicator (RMI) systems are designed for use with either an ADF or VOR station by selecting with a switch either VOR or ADF (see RMI with VOR and NDB Inputs figure, below).

2-79.jpg (13606 bytes)

The radio magnetic indicator (RMI) is both a bearing indicator and a heading indicator (see Radio Magnetic Indicator figure, below). The heading indicator uses "slaved gyro", i.e., the heading indicator is connected to a remotely located magnetic compass and is automatically "fed" directional signals. The heading indicator always shows the direction of the aircraft in relation to magnetic north.

2-78.jpg (13675 bytes)

Therefore, the pointer of the bearing indicator always displays the actual magnetic bearing to the non-directional beacon. The tail of the pointer indicates the reciprocal bearing. This system lessens the pilot's task and further minimizes the possibility of errors.

The RMI further simplifies tracking to a station because the pilot needs to refer to only one instrument instead of two. The pilot determines the magnetic heading by looking at the heading indicated on the azimuth card, and the magnetic bearing shown by the pointer. The aircraft heading used to compensate for wind drift does not influence the magnetic bearing as long as the aircraft remains on the bearing. As shown in the Tracking with an RMI figure, below, the pilot flying eastbound on the 095 magnetic bearing with 10 of north wind correction sees a display on the RMI of 085 magnetic heading (aircraft heading) and 095 magnetic bearing (to the station).

2-80.gif (3533 bytes)

The basis for this section is the Flight Training Manual by Transport Canada.   However, the text was modified for US users and readers by Dr. Claudius Carnegie of the ALLSTAR website.  Tables and/or pictures were unchanged.  Any questions should be directed to Dr. Carnegie at directly.

Send all comments to
1995-2017 ALLSTAR Network. All rights reserved worldwide.

Funded in part by

Updated: June 13, 2007