RMI open course
1.Understand the terminology.
Radial
A radial is a radio signal that starts at the station and continue out at the infinity.
Working with an RMI is very simple using radials because by imagin the station in the center of the RMI, all the radials corresponds to their specific number on compass rose.
In general pilots that uses the terminology of radial does not imply a specific track to be followed, therefore the term "radial 270" does not imply any track 090 or 270 to be flown, this could be referred to a leading radial to be crossed. This said the terminology "follow radial 270" may be considered correct, in wich case it means follow the radial 270 with a track of 270 from the station. The terminology radial 270 from or 270 outbound is correct. The terminology radial 270 to or inbound, is less common but remain correct: the radial 270 is to be flown with a track of 090 to reach inbound the station.
We will navigate making reference to radials.
Course or Bearing
The term Course is properly used if referred at VORs.
The term Bearing is properly used if referred at NDBs.
A course or a bearing is a line with a specific direction, that start at the infinity and ends at the infinity. This terminologu imply following a specific track into a specific direction.
Because of the nature infinity to infinity the course overlay by 50% a radial. A course may be inbound or to the station and outbound or from the station.
The course, as selected on an HSI or OBS, is the track that the aircraft will follow once established on the desired route.
The Course 090 inbound corresponds to Radial 270 to be followed inbound the station.
The Course 090 outbound corresponds to Radial 090 to be followed outbound the station.
The Course 270 outbound corresponds to radial 270 to be followed outbound the station.
The Course 270 inbound corresponds to radial 090 to be followed inbound the station.
Course OUTBOUND = Radial
Course INBOUND = Opposite Radial
QDM or QDR
Those terms are appropriate for both VORs ans NDBs.
This term imply following a specifi track, to the station if QDM or from the station if QDR.
QDR = Radial to follow outbound
QDM = Opposite Radial to be followed inbound