Denver TRACON controller reported a loss of separation due to an aircraft off course and slow turn r...

Attributes
ACN	1608643
Time
Date	201901
Local Time Of Day	0001-0600
Place
Locale Reference	D01.TRACON
State Reference	CO
Aircraft 1
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	Other Instrument Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	B737 Undifferentiated or Other Model
Flight Phase	Descent
Route In Use	Visual Approach
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 5
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Procedural Clearance Deviation - Track / Heading All Types

Narrative:

Working final - runway 35R at denver. Aircraft X checked in expecting RNAV zulu runway 35R approach. I issued approach clearance and pilot read back correctly. Several miles later I notice that aircraft X is 2 miles north of the RNAV zulu path - off course and heading towards the final approach fix. I deem that it is not feasible for the pilot to correct and get back on track - plus - there is another aircraft over the final approach fix and aircraft X is getting too close to that aircraft. I cancel aircraft X's clearance and instruct pilot to turn left heading 180. The pilot replies asking what altitude. I descend to 080. At this time there is another aircraft on the final for runway 35L - aircraft Y at 090. I heard the final one controller point out the traffic and instruct their aircraft to maintain visual separation. However at the same time I recognize that aircraft X's turn radius isn't looking good and issue a left turn to heading 150. I pointed out the traffic to aircraft X as well; but did not instruct aircraft X to maintain visual separation. B757's seem to always mess up the RNAV zulu approaches. My advice would be for the pilots to learn how to maneuver their airplanes properly to avoid pilot deviations that result in errors like this one.

Original NASA ASRS Text

Title: Denver TRACON Controller reported a loss of separation due to an aircraft off course and slow turn radius to get back on course. The Controller noted that this is a frequent occurrence with B757 aircraft.

Narrative: Working final - RWY 35R at Denver. Aircraft X checked in expecting RNAV Zulu RWY 35R Approach. I issued approach clearance and pilot read back correctly. Several miles later I notice that Aircraft X is 2 miles north of the RNAV Zulu path - off course and heading towards the final approach fix. I deem that it is not feasible for the pilot to correct and get back on track - plus - there is another aircraft over the final approach fix and Aircraft X is getting too close to that aircraft. I cancel Aircraft X's clearance and instruct pilot to turn left heading 180. The pilot replies asking what altitude. I descend to 080. At this time there is another aircraft on the final for RWY 35L - Aircraft Y at 090. I heard the final one controller point out the traffic and instruct their aircraft to maintain visual separation. However at the same time I recognize that Aircraft X's turn radius isn't looking good and issue a left turn to heading 150. I pointed out the traffic to Aircraft X as well; but did not instruct Aircraft X to maintain visual separation. B757's seem to always mess up the RNAV Zulu Approaches. My advice would be for the pilots to learn how to maneuver their airplanes properly to avoid pilot deviations that result in errors like this one.

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.

Denver TRACON controller reported a loss of separation due to an aircraft off course and slow turn radius to get back on course. The controller noted that this is a frequent occurrence with B757 aircraft.