Commuter air carrier light transport on visual approach to runway 28L at sfo has near midair collisi...

Attributes
ACN	127602
Time
Date	198911
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sfo
State Reference	CA
Altitude	msl bound lower : 500 msl bound upper : 1500
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : oak tower : sfo
Operator	common carrier : air carrier
Make Model Name	Light Transport, High Wing, 2 Turboprop Eng
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Heavy Transport, Low Wing, 4 Turbojet Eng
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 250 flight time total : 2600 flight time type : 1600
ASRS Report	127602
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 2950 flight time type : 800
ASRS Report	127796
Events
Anomaly	conflict : nmac incursion : landing without clearance non adherence : published procedure non adherence : far other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action
Consequence	Other
Miss Distance	horizontal : 250 vertical : 100
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

San francisco bay approach had cleared us for a visual approach for runway 28L with an heavy transport for a visual approach for runway 28R. Bay approach had informed the heavy transport that the traffic for the 28L was an small transport. (We were really an light transport. The small transport was ahead of us on the approach for runway 28L.) the heavy transport had reported the small transport in sight and was cleared for a visual approach runway 28R. Over the san mateo bridge, we were at an altitude of approximately 2500' MSL. The heavy transport was high on the approach at approximately 4000' MSL at bridge. My first officer alerted to me that the heavy transport was descending rapidly and was drifting over to the left. On a 4 mi final, the heavy transport came into my view. At approximately 1500' MSL and an approximately 2.5 mi final approach, it was evident that the heavy transport was left of the runway 28R localizer and still descending rapidly while drifting towards us. I then executed a low altitude evasive maneuver at approximately 1000' MSL which consisted of a descending left turn to 500' MSL. The heavy transport then appeared to correct its course back to runway 28R. I then applied power to stop our descent to recapture the glide slope and turn back towards the runway 28L localizer, and landed. Upon landing though, my first officer noticed that he had not switched over to the tower controller and not received clearance to land. Bay approach had not informed us to change to tower frequency due to the number of aircraft he was vectoring for runways 28L&right. My first officer and I were preoccupied on final with the drifting and descending rapidly towards us. Supplemental information from acn 127796: I feel certain that the heavy transport crew made visual contact with the wrong runway and proceeded to it. I do not believe the heavy transport crew was backing up their visual approach with the ILS 28R. When doing visual apches to parallel runways in marginal VFR conditions, I feel it is essential to utilize instrument course guidance and glide slope if available.

Original NASA ASRS Text

Title: COMMUTER ACR LTT ON VISUAL APCH TO RWY 28L AT SFO HAS NMAC WITH CARGO ACR HVT ON VISUAL APCH TO RWY 28R WHEN HVT DRIFTS TOWARD LEFT.

Narrative: SAN FRANCISCO BAY APCH HAD CLRED US FOR A VISUAL APCH FOR RWY 28L WITH AN HVT FOR A VISUAL APCH FOR RWY 28R. BAY APCH HAD INFORMED THE HVT THAT THE TFC FOR THE 28L WAS AN SMT. (WE WERE REALLY AN LTT. THE SMT WAS AHEAD OF US ON THE APCH FOR RWY 28L.) THE HVT HAD REPORTED THE SMT IN SIGHT AND WAS CLRED FOR A VISUAL APCH RWY 28R. OVER THE SAN MATEO BRIDGE, WE WERE AT AN ALT OF APPROX 2500' MSL. THE HVT WAS HIGH ON THE APCH AT APPROX 4000' MSL AT BRIDGE. MY F/O ALERTED TO ME THAT THE HVT WAS DESCENDING RAPIDLY AND WAS DRIFTING OVER TO THE LEFT. ON A 4 MI FINAL, THE HVT CAME INTO MY VIEW. AT APPROX 1500' MSL AND AN APPROX 2.5 MI FINAL APCH, IT WAS EVIDENT THAT THE HVT WAS LEFT OF THE RWY 28R LOC AND STILL DESCENDING RAPIDLY WHILE DRIFTING TOWARDS US. I THEN EXECUTED A LOW ALT EVASIVE MANEUVER AT APPROX 1000' MSL WHICH CONSISTED OF A DESCENDING LEFT TURN TO 500' MSL. THE HVT THEN APPEARED TO CORRECT ITS COURSE BACK TO RWY 28R. I THEN APPLIED POWER TO STOP OUR DSCNT TO RECAPTURE THE GLIDE SLOPE AND TURN BACK TOWARDS THE RWY 28L LOC, AND LANDED. UPON LNDG THOUGH, MY F/O NOTICED THAT HE HAD NOT SWITCHED OVER TO THE TWR CTLR AND NOT RECEIVED CLRNC TO LAND. BAY APCH HAD NOT INFORMED US TO CHANGE TO TWR FREQ DUE TO THE NUMBER OF ACFT HE WAS VECTORING FOR RWYS 28L&R. MY F/O AND I WERE PREOCCUPIED ON FINAL WITH THE DRIFTING AND DESCENDING RAPIDLY TOWARDS US. SUPPLEMENTAL INFORMATION FROM ACN 127796: I FEEL CERTAIN THAT THE HVT CREW MADE VISUAL CONTACT WITH THE WRONG RWY AND PROCEEDED TO IT. I DO NOT BELIEVE THE HVT CREW WAS BACKING UP THEIR VISUAL APCH WITH THE ILS 28R. WHEN DOING VISUAL APCHES TO PARALLEL RWYS IN MARGINAL VFR CONDITIONS, I FEEL IT IS ESSENTIAL TO UTILIZE INSTRUMENT COURSE GUIDANCE AND GLIDE SLOPE IF AVAILABLE.

Data retrieved from NASA's ASRS site as of August 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.

Commuter air carrier light transport on visual approach to runway 28L at sfo has near midair collision with cargo air carrier heavy transport on visual approach to runway 28R when heavy transport drifts toward left.