Corp aircraft has near midair collision with twin during approach.

Attributes
ACN	147470
Time
Date	199006
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : mmu
State Reference	NJ
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90 artcc : zny
Operator	general aviation : corporate
Make Model Name	Medium Transport
Navigation In Use	Other Other
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Person 1
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 8000 flight time type : 1700
ASRS Report	147470
Person 2
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Miss Distance	horizontal : 0 vertical : 100
Supplementary
Primary Problem	Ambiguous

Narrative:

Flying IFR proceeding direct to the airport on a clearance from N90 approach. We had slowed to 200 KTS. Approach asked for a further reduction to 170 KTS for spacing. Although the ATIS said 3 mi or better, the visibility at altitude was much less due to haze. Multiple VFR targets were pointed out to us at 2 O'clock and 9 O'clock positions. We did not see the traffic. The first officer returned his attention to the radar checklist. I returned my scan to straight ahead. Very suddenly I saw a white twin engine aircraft ahead. I grabbed the yoke and pulled up. The aircraft passed below. ATC said there was no primary or secondary target. A few seconds later they said a target appeared at our 6 O'clock at 2500' (500' below us). It is my opinion that the twin was skirting the TCA--a few ft below the 3000' base with his transponder off. Had we ben at a higher speed or a few ft lower, I don't think I would be here to write this. TCA's would have been a great help. Heads out of the cockpit and slow speeds in the approach area are the only defense to such unprofessional and dangerous wkend fliers who fly VFR in marginal WX in a TCA environment with no transponder.

Original NASA ASRS Text

Title: CORP ACFT HAS NMAC WITH TWIN DURING APCH.

Narrative: FLYING IFR PROCEEDING DIRECT TO THE ARPT ON A CLRNC FROM N90 APCH. WE HAD SLOWED TO 200 KTS. APCH ASKED FOR A FURTHER REDUCTION TO 170 KTS FOR SPACING. ALTHOUGH THE ATIS SAID 3 MI OR BETTER, THE VISIBILITY AT ALT WAS MUCH LESS DUE TO HAZE. MULTIPLE VFR TARGETS WERE POINTED OUT TO US AT 2 O'CLOCK AND 9 O'CLOCK POSITIONS. WE DID NOT SEE THE TFC. THE F/O RETURNED HIS ATTN TO THE RADAR CHKLIST. I RETURNED MY SCAN TO STRAIGHT AHEAD. VERY SUDDENLY I SAW A WHITE TWIN ENG ACFT AHEAD. I GRABBED THE YOKE AND PULLED UP. THE ACFT PASSED BELOW. ATC SAID THERE WAS NO PRIMARY OR SECONDARY TARGET. A FEW SECS LATER THEY SAID A TARGET APPEARED AT OUR 6 O'CLOCK AT 2500' (500' BELOW US). IT IS MY OPINION THAT THE TWIN WAS SKIRTING THE TCA--A FEW FT BELOW THE 3000' BASE WITH HIS XPONDER OFF. HAD WE BEN AT A HIGHER SPD OR A FEW FT LOWER, I DON'T THINK I WOULD BE HERE TO WRITE THIS. TCA'S WOULD HAVE BEEN A GREAT HELP. HEADS OUT OF THE COCKPIT AND SLOW SPDS IN THE APCH AREA ARE THE ONLY DEFENSE TO SUCH UNPROFESSIONAL AND DANGEROUS WKEND FLIERS WHO FLY VFR IN MARGINAL WX IN A TCA ENVIRONMENT WITH NO XPONDER.

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.