Authoritative HSI Techniques

[aterpster]

A37575:

I quite often see pilots flying a holding pattern magenta line by using the heading select mode and carefully running the aircraft along the magenta line like tracing paper and pencil. Is this a valid technique?

Most, if not all, modern FMSes have a hold mode where you can construct the required holding pattern then let the automatics fly it with positive course guidance all the way around the circuit.

If not, the magenta line's viability for manual flying depends upon the map scale set. It's far better to use the "OBS" mode (which has various names) and select the inbound holding course so the deviation indicator can be used for the inbound leg of the pattern.