TCASII TA or RA. - NASA ASRS

Attributes
ACN	279757
Time
Date	199408
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : sfo
State Reference	CA
Altitude	msl bound lower : 500 msl bound upper : 500
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tower : sfo
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : atp pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 3000 flight time type : 740
ASRS Report	279757
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : far other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Miss Distance	horizontal : 300 vertical : 0
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	other

Narrative:

We were a commercial airline 737 arriving in lax to sfo at XX00 pm. It was already dark, but the WX was clear, no significant xwinds, and visual approachs were being conducted to runways 28L and 28R. ATC vectored us right turn heading 110 degrees for the downwind, then gave us a left 180 degree for runway 28L when we were about 6-8 mi out. We were told to follow a 737 for runway 28L, but the spacing was close: ATC told us we were overtaking the 737 and asked for s-turns to the left. We were already aligned as far left as we could go and still make the landing and since we could slow from 180 to 140, I told ATC we were doing that and would south turn if necessary. As we were doing this we noted another airliner at our altitude and 300 degrees to our right, apparently aligned for runway 28L. We asked the tower which runway he was landing on. Because of the noise generated by TCASII we could not hear a reply, but we saw the other airliner bank sharply right. It was highly doubtful if there was enough room for us to safely land, so we elected at about 400 ft to go around. The go around was uneventful.

Original NASA ASRS Text

Title: TCASII TA OR RA.

Narrative: WE WERE A COMMERCIAL AIRLINE 737 ARRIVING IN LAX TO SFO AT XX00 PM. IT WAS ALREADY DARK, BUT THE WX WAS CLR, NO SIGNIFICANT XWINDS, AND VISUAL APCHS WERE BEING CONDUCTED TO RWYS 28L AND 28R. ATC VECTORED US R TURN HDG 110 DEGS FOR THE DOWNWIND, THEN GAVE US A L 180 DEG FOR RWY 28L WHEN WE WERE ABOUT 6-8 MI OUT. WE WERE TOLD TO FOLLOW A 737 FOR RWY 28L, BUT THE SPACING WAS CLOSE: ATC TOLD US WE WERE OVERTAKING THE 737 AND ASKED FOR S-TURNS TO THE L. WE WERE ALREADY ALIGNED AS FAR L AS WE COULD GO AND STILL MAKE THE LNDG AND SINCE WE COULD SLOW FROM 180 TO 140, I TOLD ATC WE WERE DOING THAT AND WOULD S TURN IF NECESSARY. AS WE WERE DOING THIS WE NOTED ANOTHER AIRLINER AT OUR ALT AND 300 DEGS TO OUR R, APPARENTLY ALIGNED FOR RWY 28L. WE ASKED THE TWR WHICH RWY HE WAS LNDG ON. BECAUSE OF THE NOISE GENERATED BY TCASII WE COULD NOT HEAR A REPLY, BUT WE SAW THE OTHER AIRLINER BANK SHARPLY R. IT WAS HIGHLY DOUBTFUL IF THERE WAS ENOUGH ROOM FOR US TO SAFELY LAND, SO WE ELECTED AT ABOUT 400 FT TO GAR. THE GAR WAS UNEVENTFUL.

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.