B757-200 on approach to bos RWY33L experiences TCAS RA with aircraft on final for runway 32.

Attributes
ACN	730216
Time
Date	200703
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bos.airport
State Reference	MA
Altitude	msl single value : 2400
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : bos.tower
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Flight Phase	descent : approach landing : go around
Route In Use	approach : visual
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : bos.tower
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	descent : approach
Route In Use	approach : visual
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 159 flight time total : 13400 flight time type : 4600
ASRS Report	730216
Person 2
Affiliation	government : faa
Function	controller : local
Events
Anomaly	conflict : airborne critical
Independent Detector	aircraft equipment : tcas
Resolutory Action	flight crew : took evasive action
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Environmental Factor Airspace Structure Airport ATC Human Performance
Primary Problem	Ambiguous

Narrative:

I was the captain and PF on a flight from ZZZ to bos. After being vectored and cleared for a visual approach to runway 33L; we were told there was another aircraft on approach to runway 32 to our left. While on approach at 2400 ft MSL; with the autoplt engaged and the localizer and GS captured we received a traffic alert followed by an RA to climb. We executed a missed approach; informed the tower and were vectored for an uneventful approach to runway 33L. Boston tower seemed surprised that we were going around; stating that the other aircraft had (us) in sight. Obviously the runway ctrlines of runways 33L and 32 converge somewhere over hingham bay. Aircraft being vectored to the 2 runways too far out run the risk of coming closer than the TCAS system allows. It appears that the other aircraft; whether or not they had us in sight; flew too close to us and caused the conflict. It's somewhat disconcerting that boston tower would vector aircraft to the 2 runways and then fail to monitor closely enough to recognize and warn them of the conflict; and would; moreover; be surprised that the proximity caused an RA.

Original NASA ASRS Text

Title: B757-200 ON APCH TO BOS RWY33L EXPERIENCES TCAS RA WITH ACFT ON FINAL FOR RWY 32.

Narrative: I WAS THE CAPT AND PF ON A FLT FROM ZZZ TO BOS. AFTER BEING VECTORED AND CLRED FOR A VISUAL APCH TO RWY 33L; WE WERE TOLD THERE WAS ANOTHER ACFT ON APCH TO RWY 32 TO OUR L. WHILE ON APCH AT 2400 FT MSL; WITH THE AUTOPLT ENGAGED AND THE LOC AND GS CAPTURED WE RECEIVED A TFC ALERT FOLLOWED BY AN RA TO CLB. WE EXECUTED A MISSED APCH; INFORMED THE TWR AND WERE VECTORED FOR AN UNEVENTFUL APCH TO RWY 33L. BOSTON TWR SEEMED SURPRISED THAT WE WERE GOING AROUND; STATING THAT THE OTHER ACFT HAD (US) IN SIGHT. OBVIOUSLY THE RWY CTRLINES OF RWYS 33L AND 32 CONVERGE SOMEWHERE OVER HINGHAM BAY. ACFT BEING VECTORED TO THE 2 RWYS TOO FAR OUT RUN THE RISK OF COMING CLOSER THAN THE TCAS SYS ALLOWS. IT APPEARS THAT THE OTHER ACFT; WHETHER OR NOT THEY HAD US IN SIGHT; FLEW TOO CLOSE TO US AND CAUSED THE CONFLICT. IT'S SOMEWHAT DISCONCERTING THAT BOSTON TWR WOULD VECTOR ACFT TO THE 2 RWYS AND THEN FAIL TO MONITOR CLOSELY ENOUGH TO RECOGNIZE AND WARN THEM OF THE CONFLICT; AND WOULD; MOREOVER; BE SURPRISED THAT THE PROX CAUSED AN RA.

Data retrieved from NASA's ASRS site as of January 2009 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.