N90 controller described a conflict event involving lga landing aircraft when an aircraft apparently...

Narrative:

I was working final for lga. Lga was on the localizer 31 approach and departing 31 due to high winds. Crj 200 was crossing over the localizer on a 060 heading. I descended crj 200 to 3;000 feet. I then issued instructions to other planes. Then I instructed crj 200 to 'reduce speed to 180 then descend and maintain 2;000 feet.' the pilot read back '180 then 2;000.' I then issued other instruction to other aircraft. And I notice crj 200 turning southbound and heading directly to another air carrier on the final which was at 1;700 feet. Since there was another plane left of crj 200 at 2;000 feet on a parallel heading; I decided to climb crj 200 and have the plane turn to the right putting the aircraft over the other air carrier. Separation was reduced to about .5 miles and several hundred feet. One disturbing aspect to the event was that the aural conflict alert did not sound. There was only a visual conflict alert on my scope. I believe this is due to the fact that the separation event was happening within 7 miles of the lga airport. I believe that the aural alarms are disabled in the TRACON within 7 miles of the airport. If this is the case; I strongly suggest that this procedure should be stopped immediately. Enable the aural alarms with no restriction of DME from the airport. I strongly suggest that this procedure should be stopped immediately.

Original NASA ASRS Text

Title: N90 Controller described a conflict event involving LGA landing aircraft when an aircraft apparently confused the instructions to reduce speed to 180 KTS; turning to 180 instead; the Controller noting the aural CA did not activate.

Narrative: I was working final for LGA. LGA was on the LOC 31 approach and departing 31 due to high winds. CRJ 200 was crossing over the localizer on a 060 heading. I descended CRJ 200 to 3;000 feet. I then issued instructions to other planes. Then I instructed CRJ 200 to 'reduce speed to 180 then descend and maintain 2;000 feet.' The pilot read back '180 then 2;000.' I then issued other instruction to other aircraft. And I notice CRJ 200 turning Southbound and heading directly to another air carrier on the final which was at 1;700 feet. Since there was another plane left of CRJ 200 at 2;000 feet on a parallel heading; I decided to climb CRJ 200 and have the plane turn to the right putting the aircraft over the other air carrier. Separation was reduced to about .5 miles and several hundred feet. One disturbing aspect to the event was that the aural Conflict Alert did not sound. There was only a visual Conflict Alert on my scope. I believe this is due to the fact that the separation event was happening within 7 miles of the LGA airport. I believe that the aural alarms are disabled in the TRACON within 7 miles of the airport. If this is the case; I strongly suggest that this procedure should be stopped immediately. Enable the aural alarms with no restriction of DME from the airport. I strongly suggest that this procedure should be stopped immediately.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1062406
Time
Date	201301
Local Time Of Day	0001-0600
Place
Locale Reference	LGA.Airport
State Reference	NY
Aircraft 1
Make Model Name	Regional Jet 200 ER/LR (CRJ200)
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Approach Departure
Qualification	Air Traffic Control Fully Certified
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Procedural Clearance Deviation - Track / Heading All Types
Miss Distance	Horizontal 2640

N90 controller described a conflict event involving lga landing aircraft when an aircraft apparently confused the instructions to reduce speed to 180 KTS; turning to 180 instead; the controller noting the aural ca did not activate.