A widebody transport aircraft on approach to sfo experienced electrical power surges and isolation o...

Attributes
ACN	357917
Time
Date	199701
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : sfo
State Reference	CA
Altitude	agl bound lower : 1300 agl bound upper : 1300
Environment
Flight Conditions	IMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : oak
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi pilot : atp
ASRS Report	357917
Person 2
Affiliation	company : air carrier
Function	flight crew : captain instruction : trainee
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa other other : unspecified cockpit
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

ATIS on arrival was indicating good WX, but showers in area. I'm the PIC in right seat (lca) conducting IOE with captain trainee in left seat flying the airplane. Initially being vectored for ILS runway 19L, we were pulled to allow lifeguard flight priority. We were changed to sfo VOR 10 approach, and being vectored (moderate rain, turbulence-doppler returns on radar), descending to MDA on approach, autoplt and autothrottles tripped off in conjunction with electrical system surge lasting about 1-2 seconds. Trainee attempted to re-engage automatic system but another surge gave same results. I took control, hand flew to missed approach and declared a miss. Approach control sent us on published miss. On the miss, had another surge and advised approach control of 'some kind of electrical problem.' controller gave us 090 degree heading and maintain 5000 ft. Thereafter, a final surge isolated #1 generator and aircraft became normal. Checked WX in oak good (2000 ft overcast 7 mi). They had full ILS capability so approach/landing oak uneventful. Maintenance found #1 CSD oil quantity low.

Original NASA ASRS Text

Title: A WDB ACFT ON APCH TO SFO EXPERIENCED ELECTRICAL PWR SURGES AND ISOLATION OF #1 BUS. ACFT DIVERTED TO OAK. FOUND #1 CSD OIL QUANTITY LOW.

Narrative: ATIS ON ARR WAS INDICATING GOOD WX, BUT SHOWERS IN AREA. I'M THE PIC IN R SEAT (LCA) CONDUCTING IOE WITH CAPT TRAINEE IN L SEAT FLYING THE AIRPLANE. INITIALLY BEING VECTORED FOR ILS RWY 19L, WE WERE PULLED TO ALLOW LIFEGUARD FLT PRIORITY. WE WERE CHANGED TO SFO VOR 10 APCH, AND BEING VECTORED (MODERATE RAIN, TURB-DOPPLER RETURNS ON RADAR), DSNDING TO MDA ON APCH, AUTOPLT AND AUTOTHROTTLES TRIPPED OFF IN CONJUNCTION WITH ELECTRICAL SYS SURGE LASTING ABOUT 1-2 SECONDS. TRAINEE ATTEMPTED TO RE-ENGAGE AUTO SYS BUT ANOTHER SURGE GAVE SAME RESULTS. I TOOK CTL, HAND FLEW TO MISSED APCH AND DECLARED A MISS. APCH CTL SENT US ON PUBLISHED MISS. ON THE MISS, HAD ANOTHER SURGE AND ADVISED APCH CTL OF 'SOME KIND OF ELECTRICAL PROB.' CTLR GAVE US 090 DEG HDG AND MAINTAIN 5000 FT. THEREAFTER, A FINAL SURGE ISOLATED #1 GENERATOR AND ACFT BECAME NORMAL. CHKED WX IN OAK GOOD (2000 FT OVCST 7 MI). THEY HAD FULL ILS CAPABILITY SO APCH/LNDG OAK UNEVENTFUL. MAINT FOUND #1 CSD OIL QUANTITY LOW.

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.

A widebody transport aircraft on approach to sfo experienced electrical power surges and isolation of #1 bus. Aircraft diverted to oak. Found #1 CSD oil quantity low.