B737 had near midair collision with VFR small aircraft. See and avoid concept.

Attributes
ACN	314250
Time
Date	199508
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : alb
State Reference	NY
Altitude	msl bound lower : 2500 msl bound upper : 2500
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : alb
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach descent other
Route In Use	arrival other enroute : on vectors
Flight Plan	IFR
Aircraft 2
Operator	general aviation : personal
Make Model Name	PA-28 Cherokee/Archer II/Dakota/Pillan/Warrior
Operating Under FAR Part	Part 91
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller non radar : 7 controller radar : 2
ASRS Report	314250
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : nmac non adherence : far
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted none taken : insufficient time
Consequence	faa : reviewed incident with flight crew
Miss Distance	vertical : 300
Supplementary
Primary Problem	Flight Crew Human Performance

Narrative:

I was working moderate traffic at east feeder/final vector combined position. The radar presentation was marginal as coverage south of the airport down low was poor. After I turned and cleared the B737 for the ILS runway 01 approach, the pilot reported seeing a PA28 fly underneath them. I did not observe any aircraft targets in the path of the B737. The pilot had nothing on his TCASII either. The cause of the problem was the PA28 did not have a transponder operating and the alb tower radar system is poor at best for tracking primary only targets. The awareness of the PA28 pilot was not great, he had no transponder, he was flying just under the cloud deck, and he was right on final approach at the intercept altitude.

Original NASA ASRS Text

Title: B737 HAD NMAC WITH VFR SMA. SEE AND AVOID CONCEPT.

Narrative: I WAS WORKING MODERATE TFC AT E FEEDER/FINAL VECTOR COMBINED POS. THE RADAR PRESENTATION WAS MARGINAL AS COVERAGE S OF THE ARPT DOWN LOW WAS POOR. AFTER I TURNED AND CLRED THE B737 FOR THE ILS RWY 01 APCH, THE PLT RPTED SEEING A PA28 FLY UNDERNEATH THEM. I DID NOT OBSERVE ANY ACFT TARGETS IN THE PATH OF THE B737. THE PLT HAD NOTHING ON HIS TCASII EITHER. THE CAUSE OF THE PROB WAS THE PA28 DID NOT HAVE A XPONDER OPERATING AND THE ALB TWR RADAR SYS IS POOR AT BEST FOR TRACKING PRIMARY ONLY TARGETS. THE AWARENESS OF THE PA28 PLT WAS NOT GREAT, HE HAD NO XPONDER, HE WAS FLYING JUST UNDER THE CLOUD DECK, AND HE WAS R ON FINAL APCH AT THE INTERCEPT ALT.

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.