An air carrier light transport flew out the bottom of the sfo class 'B' airspace.

Attributes
ACN	274307
Time
Date	199406
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sfo
State Reference	CA
Altitude	msl bound lower : 5500 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sfo
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	descent : approach ground : preflight
Route In Use	approach : visual arrival other enroute airway : sjc
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 290 flight time total : 6600 flight time type : 2300
ASRS Report	274307
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance non adherence : published procedure
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

While on approach (the san francisco quite bridge visual runway 28R) at 23 mi out, the captain was flying he airplane -- it was brought to our attention by ATC that we had descended through 6000 ft and he queried us 'aren't you aware that three is an 18.0 restr to maintain 6000 ft?' the captain replied, 'I'm sorry I thought it was 23 DME.' we were currently at 5500 ft. ATC responded 'maintain 6000 ft until 18.0 DME for san jose arrs and departures.' we were definitely at fault and were busy trying to solve a nose wheel steering failure that was happening. We had a 'pedal steer inoperative' light come on. I had my head in the quick reference handbook to analyze/read what to do. We should have been referencing the charts we had out on the approach. Instead we were discussing the procedures we would follow to handle the emergency. I feel that if we weren't so involved, the altitude incursion on the approach would not have happened. On final approach to a busy airport like sfo is not the place for such problem solving. We should have delayed our approach.

Original NASA ASRS Text

Title: AN ACR LTT FLEW OUT THE BOTTOM OF THE SFO CLASS 'B' AIRSPACE.

Narrative: WHILE ON APCH (THE SAN FRANCISCO QUITE BRIDGE VISUAL RWY 28R) AT 23 MI OUT, THE CAPT WAS FLYING HE AIRPLANE -- IT WAS BROUGHT TO OUR ATTN BY ATC THAT WE HAD DSNDED THROUGH 6000 FT AND HE QUERIED US 'AREN'T YOU AWARE THAT THREE IS AN 18.0 RESTR TO MAINTAIN 6000 FT?' THE CAPT REPLIED, 'I'M SORRY I THOUGHT IT WAS 23 DME.' WE WERE CURRENTLY AT 5500 FT. ATC RESPONDED 'MAINTAIN 6000 FT UNTIL 18.0 DME FOR SAN JOSE ARRS AND DEPS.' WE WERE DEFINITELY AT FAULT AND WERE BUSY TRYING TO SOLVE A NOSE WHEEL STEERING FAILURE THAT WAS HAPPENING. WE HAD A 'PEDAL STEER INOP' LIGHT COME ON. I HAD MY HEAD IN THE QUICK REF HANDBOOK TO ANALYZE/READ WHAT TO DO. WE SHOULD HAVE BEEN REFERENCING THE CHARTS WE HAD OUT ON THE APCH. INSTEAD WE WERE DISCUSSING THE PROCS WE WOULD FOLLOW TO HANDLE THE EMER. I FEEL THAT IF WE WEREN'T SO INVOLVED, THE ALT INCURSION ON THE APCH WOULD NOT HAVE HAPPENED. ON FINAL APCH TO A BUSY ARPT LIKE SFO IS NOT THE PLACE FOR SUCH PROB SOLVING. WE SHOULD HAVE DELAYED OUR APCH.

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.