Originally Posted by
block30
To qoute John Eckalbar, author of IFR A Structured Approach,
"...we are not to turn onto a DME arc at a randomly encountered location on the arc-arcs are to be entered only at the depicted IAF's on the arc." "...if we come up the (XXX radial) towards (XXX VOR), we can't take a quick left on the 10 DME arc and take advantage of its "NoPT" feature."
That was a question I had when I was training for my instrument, "can I just turn onto the arc and be good to go?" Unfortunately not. I'm trying to find AIM reference, but so far Eckalbar's words have been quickest to find.
I say this only to clarify how arcs are supposed to be entered.
Best to you, block30
An airline pilot may wish to comment on this because they fly only IFR and would know more about real world practices; but I think if you are cleared to intercept a particular DME arc by a controller then you may do so, and you do not have to fly to one of the two llustrated IAFs on the arc if you have the clearance.