The 747 does not have a "NAV" or VOR tracking mode in its autopilot
system like those you may have seen on other aircraft. It is quite easy
to do though using the FMC:
- Enter the VOR you wish to track a radial TO or FROM on the LEGS
page at LSK 1L. (Just as you'd do to go direct to it)
- Now, enter the correct course for the radial (same as what
you'd set a CDI gauge's OBS knob to) into the INTC CRS prompt that
appears at LSK 6R after step 1.
- Press EXEC
You should now see a magenta line extending to infinity on the course
you specified. Turn toward it and arm LNAV. The plane will capture it
and you'll be on your way.