N90 TRACON controller and pilot reported the pilot flew through approach course and towards another ...

Attributes
ACN	1700894
Time
Date	201911
Local Time Of Day	0601-1200
Place
Locale Reference	TEB.Airport
State Reference	NJ
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft
Operating Under FAR Part	Part 91
Flight Phase	Final Approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Medium Transport
Flight Phase	Final Approach
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 1.0
Person 2
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Instrument
Experience	Flight Crew Last 90 Days 132 Flight Crew Total 2107 Flight Crew Type 1330
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

Aircraft X was cleared for ILS 6 approach to teb. Shortly after; I noticed him go through the localizer and called the tower to give instructions to rejoin approach. At the same time I received a low altitude alert and told the tower. I called tower to alert them because it appeared to me he might be heading toward their airport. Shortly after it appeared he was turning west bound towards aircraft Y and at some point I heard the tower say over the shout line that he wasn't following instructions. I turned aircraft Y northwest to try to get away from aircraft X. To me it looked like aircraft X was headed right at aircraft Y so I climbed aircraft Y to 3;000 feet since I told tower to have aircraft X climb to 2;000 feet. This vector brought aircraft Y into conflict with aircraft Z. Once it appeared aircraft Y and aircraft X were no longer a factor I turned aircraft Y back to a 340 heading away from aircraft Z. Separation was re-established between all aircraft and they were re-sequenced to the airport.if aircraft X had flown the approach as cleared or been issued the 030 heading to rejoin that I initially issued to the tower; this would have never happened. I was worried about aircraft Y and aircraft X hitting which caused me to turn aircraft Y into aircraft Z. In hindsight I could have probably used less of a turn for aircraft Y so that I would have at least had divergence with aircraft Z; but at the time was more concerned about aircraft Y and aircraft X actually hitting that the loss of separation with aircraft Z seemed less critical so I can't say I wouldn't do the same thing in the future. As I discussed with my supervisor after the incident the one thing I would do differently is not ship aircraft X to the tower so soon. It may not have prevented the incident but may have helped make it easier to control if I didn't have to coordinate with the tower and was directly talking to the aircraft.

Original NASA ASRS Text

Title: N90 TRACON Controller and pilot reported the pilot flew through approach course and towards another aircraft before pilot was reoriented and communications restored.

Narrative: Aircraft X was cleared for ILS 6 approach to TEB. Shortly after; I noticed him go through the localizer and called the Tower to give instructions to rejoin approach. At the same time I received a low altitude alert and told the Tower. I called Tower to alert them because it appeared to me he might be heading toward their airport. Shortly after it appeared he was turning west bound towards Aircraft Y and at some point I heard the Tower say over the shout line that he wasn't following instructions. I turned Aircraft Y northwest to try to get away from Aircraft X. To me it looked like Aircraft X was headed right at Aircraft Y so I climbed Aircraft Y to 3;000 feet since I told Tower to have Aircraft X climb to 2;000 feet. This vector brought Aircraft Y into conflict with Aircraft Z. Once it appeared Aircraft Y and Aircraft X were no longer a factor I turned Aircraft Y back to a 340 heading away from Aircraft Z. Separation was re-established between all Aircraft and they were re-sequenced to the airport.If Aircraft X had flown the approach as cleared or been issued the 030 heading to rejoin that I initially issued to the Tower; this would have never happened. I was worried about Aircraft Y and Aircraft X hitting which caused me to turn Aircraft Y into Aircraft Z. In hindsight I could have probably used less of a turn for Aircraft Y so that I would have at least had divergence with Aircraft Z; but at the time was more concerned about Aircraft Y and Aircraft X actually hitting that the loss of separation with Aircraft Z seemed less critical so I can't say I wouldn't do the same thing in the future. As I discussed with my supervisor after the incident the one thing I would do differently is not ship Aircraft X to the Tower so soon. It may not have prevented the incident but may have helped make it easier to control if I didn't have to coordinate with the Tower and was directly talking to the aircraft.

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.

N90 TRACON controller and pilot reported the pilot flew through approach course and towards another aircraft before pilot was reoriented and communications restored.