Thanks for the replies! Kabz I have read a few of Don Browns articles on Avweb and thanks for the link to that one
Vector4fun thanks for your input. I used the term clearance limit inappropriately. Let me try again; Enroute to KGRR with several fixes between me and the airport including the Grand Rapids VOR, an unsolicited clearance comes across the airwaves; "lear 123 cleared direct to Grand Rapids" No mention of airport or aerodrome is made, what is my next fix? I ask this because some controllers are absolutly adamant that you must proceed to the navaid others to the airport. I fly an aircraft with dual FMS`, if one pilot selects direct to the airport and the other to the navaid, as one gets closer the flight directors diverge! I was just curious if there was any published procedures specifically addressing co-named/located airports/navaids. Thanks again.