EMB ERJ 170/175 ER/LR
Air Traffic Control Fully Certified
Communication Breakdown
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors
E170/Q; (MEM J42 GVE KORRY3) was navigating direct GVE instead of navigating via J42.  When [the crew] was challenged on their route; they stated the flight plan they filed was TXK J42 GVE and they were given an amended PDC of TXK J42 MEM then as filed.  They understood the PDC to mean proceed direct GVE after MEM.  Other than the call sign; this incident is exactly the same as another incident I investigated back in [a few months ago] involving a Hawker.  Like the E170; the Hawker (BKW J42 GVE JAIKE3) departed out of Dallas-Ft. Worth airspace and proceeded direct GVE after MEM due to the same amended PDC (TXK J42 MEM then as filed).Two possible options in order to rectify the situation:1) Move the last fix of the amended PDC back further west on J42 2) Treat an amended PDC as a FRC and read the entire clearance3) Pilot education
We received our PDC and it stated: TRISS4 TXK J42 GVE KORRY3. There was an amendment above and it stated: TRISS4 TXK J42 MEM. We thought that we were supposed to fly direct from MEM to GVE. ATC wanted us to remain on J42 to GVE from MEM. The original filed flight plan was what we were supposed to fly.The amendment was confusing and there was no need for it. ATC should not use amendments unless there is an actual change in the route. Or if they want to use the amendment; then they should provide the whole route (including all fixes) on the route.
A ZID Controller and the flight crew involved describe a track deviation due to a misunderstanding of the amended PDC.