B767 initiates TCASII RA maneuver to avoid a B757 when on vector to bos runway 4R final approach cou...

Attributes
ACN	554970
Time
Date	200207
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : bos.airport
State Reference	MA
Altitude	msl single value : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : a90.tracon
Operator	common carrier : air carrier
Make Model Name	B767-200
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 4r other
Flight Phase	descent : approach
Route In Use	approach : instrument non precision
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tracon : a90.tracon
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 150 flight time total : 15000 flight time type : 900
ASRS Report	554970
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : nmac non adherence : published procedure non adherence : required legal separation
Independent Detector	atc equipment other atc equipment : radar aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : took evasive action
Consequence	faa : investigated faa : reviewed incident with flight crew
Miss Distance	horizontal : 100 vertical : 350
Supplementary
Problem Areas	ATC Human Performance Environmental Factor
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Inbound to boston. We were flying the localizer (runway 4R) at 5000 ft. We were cleared to 4000 ft and started a descent. We noticed traffic on TCASII at 4000 ft, below us, and thought it must be opposite direction or going to the other runway. At 3400 ft, we got a climb RA from TCASII. We both looked over the nose and saw a B757, 400 ft below, and almost directly underneath us. We started a climb about the same time the controller told us to maintain 5000 ft. At the closest, we were about 350 ft above him. We were vectored out for another approach, which was normal, and landed. I called approach control and spoke to the supervisor. He said they listened to the tapes and it was controller error. The controller had sounded almost overloaded the whole time we were on his frequency.

Original NASA ASRS Text

Title: B767 INITIATES TCASII RA MANEUVER TO AVOID A B757 WHEN ON VECTOR TO BOS RWY 4R FINAL APCH COURSE BY A80.

Narrative: INBOUND TO BOSTON. WE WERE FLYING THE LOC (RWY 4R) AT 5000 FT. WE WERE CLRED TO 4000 FT AND STARTED A DSCNT. WE NOTICED TFC ON TCASII AT 4000 FT, BELOW US, AND THOUGHT IT MUST BE OPPOSITE DIRECTION OR GOING TO THE OTHER RWY. AT 3400 FT, WE GOT A CLB RA FROM TCASII. WE BOTH LOOKED OVER THE NOSE AND SAW A B757, 400 FT BELOW, AND ALMOST DIRECTLY UNDERNEATH US. WE STARTED A CLB ABOUT THE SAME TIME THE CTLR TOLD US TO MAINTAIN 5000 FT. AT THE CLOSEST, WE WERE ABOUT 350 FT ABOVE HIM. WE WERE VECTORED OUT FOR ANOTHER APCH, WHICH WAS NORMAL, AND LANDED. I CALLED APCH CTL AND SPOKE TO THE SUPVR. HE SAID THEY LISTENED TO THE TAPES AND IT WAS CTLR ERROR. THE CTLR HAD SOUNDED ALMOST OVERLOADED THE WHOLE TIME WE WERE ON HIS FREQ.

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.

B767 initiates TCASII RA maneuver to avoid a B757 when on vector to bos runway 4R final approach course by A80.