Narrative:

While pilot flying on the dlamp 5 arrival into sdf landing north and expecting runway 35R; shortly after nerve on the arrival we were told to proceed direct to brell and then rejoin the arrival. This was a shortcut because it allowed us to cut a corner on the arrival; saving a short amount of time. I put direct brell into the FMS and confirmed with the pilot monitoring before activating; taking us direct to brell. Brell is the last fix on the arrival; after which the arrival instructs to track a 171 degree course; so I had previously put in a waypoint on a 171 bearing from brell and out 15 miles so we had a course to track after brell. After crossing over brell; the aircraft turned to track the 171 course; but we were right of course due to brell being a flyover waypoint and not a flyby waypoint on the arrival procedure. The controller informed us we were 2 miles right of course; and that if there had been an aircraft on final there would not be adequate separation. The controller told us it wasn't a big deal; gave us a heading for a base turn and cleared us for the visual without further event.the problem arrived due to the clearance to proceed direct to brell; which made us arrive at a 45 degree or greater angle. Brell is a flyover waypoint; so we cannot turn early than brell according to the arrival procedure. Normally on the arrival aircraft arrive at brell already on a 170 degree course; so brell being a flyover waypoint is not an issue. Clearances that bring you to brell at a steep angle will cause you to overshoot and incur on the final approach course; but turning before brell is technically not following the arrival procedure.

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Original NASA ASRS Text

Title: EMB-175 pilot reported track deviation while on the DLAMP 5 arrival into SDF due to having been cleared by ATC direct to a flyover waypoint and procedurally not being able to turn early.

Narrative: While Pilot Flying on the DLAMP 5 Arrival into SDF landing north and expecting Runway 35R; shortly after NERVE on the arrival we were told to proceed direct to BRELL and then rejoin the arrival. This was a shortcut because it allowed us to cut a corner on the arrival; saving a short amount of time. I put direct BRELL into the FMS and confirmed with the Pilot Monitoring before activating; taking us direct to BRELL. BRELL is the last fix on the arrival; after which the arrival instructs to track a 171 degree course; so I had previously put in a waypoint on a 171 bearing from BRELL and out 15 miles so we had a course to track after BRELL. After crossing over BRELL; the aircraft turned to track the 171 course; but we were right of course due to BRELL being a flyover waypoint and not a flyby waypoint on the arrival procedure. The Controller informed us we were 2 miles right of course; and that if there had been an aircraft on final there would not be adequate separation. The Controller told us it wasn't a big deal; gave us a heading for a base turn and cleared us for the visual without further event.The problem arrived due to the clearance to proceed direct to BRELL; which made us arrive at a 45 degree or greater angle. BRELL is a flyover waypoint; so we cannot turn early than BRELL according to the arrival procedure. Normally on the arrival aircraft arrive at BRELL already on a 170 degree course; so BRELL being a flyover waypoint is not an issue. Clearances that bring you to BRELL at a steep angle will cause you to overshoot and incur on the final approach course; but turning before BRELL is technically not following the arrival procedure.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.