Commercial Fixed Wing
Confusion; Situational Awareness
Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Human Factors; Chart Or Publication
During taxi out we were cleared from parking to Runway 19 via E; D; S; cross Runway 10. We responded correctly; put the taxi instructions in the scratch pad of the FMS; but misread the taxi diagram where 'D' appears to follow the ramp due east. I did not recognize or notice the diagonal taxiway with another 'D' north of Runway 10. We noted our error when Ground Control told us to turn left on Taxiway F; cross 10 and join Taxiway D. I read back the instruction and apologized. ATC responded 'no problem; that's what we're here for. Both of us missed Taxiway D on the parking diagram; thinking instead that D ran eastbound parallel to Runway 10. Neither of us fly to MSY often. Judging by ATC's reaction this might be a good place for a 'hotspot' note.
Cleared to taxi from parking to Runway 19 via E; D; S. Responded to clearance traced route in highlight on [airport diagram] and input route in scratch pad of FMS. The [airport diagram] has Taxiway D labeled on Taxiway E east of the actual D Taxiway. When I highlighted the route I drew through the letter D not the actual taxiway then followed the line past the intersection. Ground notified us when past D Intersection and recleared via alternate route. No further discrepancies occurred. Fix the chart. Take extra time even when the route and airport layout seems easy.
Air Carrier flight crew misunderstands a taxi clearance at MSY and believes that Taxiway E turns into Taxiway D; when in fact D is the diagonal; due to the location of the D near Taxiway E on the airport diagram. An electronic display of the airport diagram was being used for taxi and the assumed route had been highlighted.