TCASII RA causes evasive action go around.

Attributes
ACN	280040
Time
Date	199408
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : sea
State Reference	WA
Altitude	agl bound lower : 500 agl bound upper : 700
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sea
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach landing : missed approach
Route In Use	approach : visual arrival other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	descent : approach landing other
Route In Use	approach : visual arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 14000 flight time type : 1000
ASRS Report	280040
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	conflict : nmac conflict : airborne less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa other other : unspecified
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 200 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Received 'climb, climb now' TCASII RA on close final to sea runway 34R while on visual approach. First thought was someone was cutting across the final in front of us but after the fact, am sure it was caused by an md-80 on a visual to runway 34L catching up to us. Approach control pointed out the md-80 turning in from the west and, when we turned final at about 10 mi, the md-80 was at our 8 O'clock and about 1 mi. TCASII displayed the md-80 on the navigation display and, since I was already aware of it and doing a visual approach, I lost interest in the navigation display and was concentrating on the ILS information on the primary flight display. As I understand TCASII, it was watching the md-80 and finally decided it was too close and issued the RA. The RA caught us by surprise and by the time I looked around after initiating the go around the md-80 was slightly below and in line with the left wing tip. A normal glide path to runway 34L would have the md-80 above us at the time of the RA. To prevent unnecessary RA's and gars, our procedure is to select TA only on visual approachs when we have the other traffic in sight. This incident was caused by the other aircraft closing on us from behind. The md-80 may have moved to the right of centerline also but I can't be sure. Several passenger said they got a real close look at it.

Original NASA ASRS Text

Title: TCASII RA CAUSES EVASIVE ACTION GAR.

Narrative: RECEIVED 'CLB, CLB NOW' TCASII RA ON CLOSE FINAL TO SEA RWY 34R WHILE ON VISUAL APCH. FIRST THOUGHT WAS SOMEONE WAS CUTTING ACROSS THE FINAL IN FRONT OF US BUT AFTER THE FACT, AM SURE IT WAS CAUSED BY AN MD-80 ON A VISUAL TO RWY 34L CATCHING UP TO US. APCH CTL POINTED OUT THE MD-80 TURNING IN FROM THE W AND, WHEN WE TURNED FINAL AT ABOUT 10 MI, THE MD-80 WAS AT OUR 8 O'CLOCK AND ABOUT 1 MI. TCASII DISPLAYED THE MD-80 ON THE NAV DISPLAY AND, SINCE I WAS ALREADY AWARE OF IT AND DOING A VISUAL APCH, I LOST INTEREST IN THE NAV DISPLAY AND WAS CONCENTRATING ON THE ILS INFO ON THE PRIMARY FLT DISPLAY. AS I UNDERSTAND TCASII, IT WAS WATCHING THE MD-80 AND FINALLY DECIDED IT WAS TOO CLOSE AND ISSUED THE RA. THE RA CAUGHT US BY SURPRISE AND BY THE TIME I LOOKED AROUND AFTER INITIATING THE GAR THE MD-80 WAS SLIGHTLY BELOW AND IN LINE WITH THE L WING TIP. A NORMAL GLIDE PATH TO RWY 34L WOULD HAVE THE MD-80 ABOVE US AT THE TIME OF THE RA. TO PREVENT UNNECESSARY RA'S AND GARS, OUR PROC IS TO SELECT TA ONLY ON VISUAL APCHS WHEN WE HAVE THE OTHER TFC IN SIGHT. THIS INCIDENT WAS CAUSED BY THE OTHER ACFT CLOSING ON US FROM BEHIND. THE MD-80 MAY HAVE MOVED TO THE R OF CTRLINE ALSO BUT I CAN'T BE SURE. SEVERAL PAX SAID THEY GOT A REAL CLOSE LOOK AT IT.

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.