Situational Awareness; Human-Machine Interface; Distraction; Confusion; Communication Breakdown; Troubleshooting; Workload
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Chart Or Publication; Procedure; Human Factors
Enroute to ZZZ.  The original destination requested by the passengers was TEB; but the destination was changed to ZZZ due to expected 1 hour plus delays at TEB.   We departed with the understanding that we would check with ATC enroute and if TEB didn't have delays; we would land there.  Just after crossing ITH VOR; about 30 minutes out we were handed to Boston Center.  We queried the controller and were told that TEB no longer had delays.  We requested and were granted a clearance to TEB.   The new clearance was HNK V167 WEARD V489 COATE direct TEB which we repeated and entered into the FMS.  I briefly compared the major points in the FMS with the enroute charts in [the tablet].  Everything seemed to agree.  The controller begin assigning multiple descents and I was on the phone with [Company name removed] letting them know to switch destinations and arrange ground transportation.  Things were very busy in the cockpit.  About 20 minutes out from TEB; the controller told us; 'Aircraft X cleared direct to RUBER.  R-U-B-E-R (spelled out with letters; not phonetically).  Cross RUBER at 7;000.'   I read the clearance back and the [pilot flying] already started entering the point in the FMS scratchpad.   Initially he had heard the spelling as RUBBR and entered that.  That was a waypoint 2;000 miles away.  I corrected him and he entered the correct point RUBER.   Neither of us saw RUBER as a point in the FMS.   This combined with the fact that the controller had spelled it out as if it was a new waypoint; led both of us to believe we had been given a new clearance to TEB.  We crossed RUBER at 7;000 and turned direct to TEB not realizing that RUBER was a point on V489 and the controller had still wanted us to maintain the remainder of the originally assigned route.  A few moments later the controller asked us if we were turning to HUO.  We replied that we understood our clearance to be RUBER direct to TEB.  He stated that RUBER was on V489 and wanted us to still maintain the remainder of the route.  Because we had entered a new route in the box; it wiped out the original route.  We asked for a vector to HUO and worked to quickly get it programmed in the FMS.  The vector given was 190 degrees.  Then the controller then told us to turn direct COATE.  Things were very busy; but we got it in the FMS and began following the route.   After COATE we turned direct to TEB.  ATC (now New York Approach) then asked us what our heading was.  We stated that we were direct TEB (approximate heading 135).  ATC stated that he had given us a heading of 200 degrees.  Neither of us ever remember getting this clearance or reading it back.  We promptly turned to a heading of 200.  At no time did we ever appear to be close to other aircraft or be in danger of causing a Traffic Alert.   In the future; I will be more diligent to verify that a point we are cleared to is indeed a new point and not an existing point on our route.  I believe this confusion was greatly compounded by the well-meaning controller who spelled out the fix.  This phraseology is typical with a new route; but not a clearance to a point on an existing route.  My assumption was that we had been given a new clearance.  In the future I will ask ATC if there seems to be any confusion.  The confusion of the clearance may have then led us to miss a call from ATC; but we didn't ever read the clearance back or respond; so it would have been helpful for ATC to make a follow-up call to ensure we received the 200 degree heading clearance.
A pilot reported confusion with ATC on a waypoint. When the crew entered the new waypoint it wiped out the existing route and took the flight slightly off course. The Controller issued one heading but the crew heard another then corrected it.