Close proximity air carrier-large transport GA-unknown in N90 TCA.

Attributes
ACN	199456
Time
Date	199201
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : rbv airport : ewr
State Reference	NJ
Altitude	msl bound lower : 4800 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : n90
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other
Flight Plan	VFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 9700 flight time type : 7500
ASRS Report	199456
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot conflict : airborne less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 3000 vertical : 300
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

After crossing robbinsville VOR, cleared to 4000 ft by ny approach. In descent, approach called 'VFR traffic 2 O'clock and 5 mi at 4500 ft heading southwest.' I reported 'traffic not in sight.' approximately 30 seconds later I asked for 'traffic position.' approach said '1 O'clock and 3 mi.' VFR traffic reported he had us in sight. I asked approach 'do you want us at 5 or 4000 ft' as we were just passing 5000 ft. Approach replied 'you were cleared to 5000.' I said we would climb back to 5000 ft. Our lowest descent was to 4800 ft. After passing within 1/2 mi approach then cleared us to 4000. During handoff to next sector the controller thanked us for a heads up. Ny approach was talking to an air carrier egh at some time and instructed them to maintain 5000 ft. Our flight number was dgh. The ATC voice tape was reviewed by ATC and our flight safety department which revealed that approach had indeed made a grave error.

Original NASA ASRS Text

Title: CLOSE PROX ACR-LGT GA-UNKNOWN IN N90 TCA.

Narrative: AFTER XING ROBBINSVILLE VOR, CLRED TO 4000 FT BY NY APCH. IN DSCNT, APCH CALLED 'VFR TFC 2 O'CLOCK AND 5 MI AT 4500 FT HDG SW.' I RPTED 'TFC NOT IN SIGHT.' APPROX 30 SECONDS LATER I ASKED FOR 'TFC POS.' APCH SAID '1 O'CLOCK AND 3 MI.' VFR TFC RPTED HE HAD US IN SIGHT. I ASKED APCH 'DO YOU WANT US AT 5 OR 4000 FT' AS WE WERE JUST PASSING 5000 FT. APCH REPLIED 'YOU WERE CLRED TO 5000.' I SAID WE WOULD CLB BACK TO 5000 FT. OUR LOWEST DSCNT WAS TO 4800 FT. AFTER PASSING WITHIN 1/2 MI APCH THEN CLRED US TO 4000. DURING HDOF TO NEXT SECTOR THE CTLR THANKED US FOR A HEADS UP. NY APCH WAS TALKING TO AN ACR EGH AT SOME TIME AND INSTRUCTED THEM TO MAINTAIN 5000 FT. OUR FLT NUMBER WAS DGH. THE ATC VOICE TAPE WAS REVIEWED BY ATC AND OUR FLT SAFETY DEPT WHICH REVEALED THAT APCH HAD INDEED MADE A GRAVE ERROR.

Data retrieved from NASA's ASRS site as of July 2007 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.