N90 controller described an unsafe condition during a busy period when weather required multiple avo...

Narrative:

There were thunderstorms to the north of my airspace; causing me to take aircraft via non-standard procedures and feed aircraft via non-standard procedures. A dash was on a vector eastbound to keep him south of all the weather; I had just take a hand off from the east on the hawker at 4;000 ft. The dash was head on at 3;000 ft with 20 miles between them. On initial contact I descended the hawker jet to 2;000 ft. I was expecting a normal rate of descent from the hawker; however; his descent rate was very slow and not standard at all. I missed this because I was vectoring another aircraft up to the north between some of the storms as well. Then another controller called to coordinate another aircraft from the east; as I was answering and coordinating with him I noticed the hawker jet had gone about 8-10 miles and was only then just descending through 3;000 ft; head on with the dash with only about 4-5 miles between them. One minute prior to this; the dash had asked for a deviation of 10 degrees to the right which I had approved. When I became aware of the head-on; I told the hawker jet to expedite his descent and called the traffic. I instructed the dash to turn back to the left for traffic and issued the traffic. I then went back to the hawker and turned him to the left and issued traffic again. He reported the dash in sight. The closest the 2 aircraft came was 300 ft vertically and .9 miles laterally. When weather is in the area; we should not be bending airspace rules and procedures. If they aircraft can't get through; then let them go and hold somewhere for a while and/or divert until the weather passes. Working outside my airspace; making all the co-ordinations and point outs myself caused me to miss the slow descent rate which the hawker jet was performing and nearly caused a mid-air collision.

Original NASA ASRS Text

Title: N90 Controller described an unsafe condition during a busy period when weather required multiple avoidance vectors and altering airspace procedures a condition that is not safe according to the reporter.

Narrative: There were thunderstorms to the north of my airspace; causing me to take aircraft via non-standard procedures and feed aircraft via non-standard procedures. A Dash was on a vector eastbound to keep him south of all the weather; I had just take a hand off from the east on the Hawker at 4;000 FT. The Dash was head on at 3;000 FT with 20 miles between them. On initial contact I descended the Hawker jet to 2;000 FT. I was expecting a normal rate of descent from the Hawker; however; his descent rate was very slow and not standard at all. I missed this because I was vectoring another aircraft up to the north between some of the storms as well. Then another controller called to coordinate another aircraft from the east; as I was answering and coordinating with him I noticed the Hawker jet had gone about 8-10 miles and was only then just descending through 3;000 FT; head on with the Dash with only about 4-5 miles between them. One minute prior to this; the Dash had asked for a deviation of 10 degrees to the right which I had approved. When I became aware of the head-on; I told the Hawker jet to expedite his descent and called the traffic. I instructed the Dash to turn back to the left for traffic and issued the traffic. I then went back to the Hawker and turned him to the left and issued traffic again. He reported the Dash in sight. The closest the 2 aircraft came was 300 FT vertically and .9 miles laterally. When weather is in the area; we should not be bending airspace rules and procedures. If they aircraft can't get through; then let them go and hold somewhere for a while and/or divert until the weather passes. Working outside my airspace; making all the co-ordinations and point outs myself caused me to miss the slow descent rate which the Hawker jet was performing and nearly caused a mid-air collision.

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	1023642
Time
Date	201207
Local Time Of Day	1801-2400
Place
Locale Reference	N90.TRACON
State Reference	NY
Aircraft 1
Make Model Name	Dash 8 Series Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	HS 125 Series
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
Miss Distance	Horizontal 4752 Vertical 300

N90 controller described an unsafe condition during a busy period when weather required multiple avoidance vectors and altering airspace procedures a condition that is not safe according to the reporter.