Private pilot flew through localizer, descended early, before receiving approach clearance.

Attributes
ACN	178457
Time
Date	199105
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : oak
State Reference	CA
Altitude	msl bound lower : 2000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : oak
Operator	general aviation : instructional
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	descent : approach descent other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 10 flight time total : 330 flight time type : 220
ASRS Report	178457
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other spatial deviation
Independent Detector	other controllera other other : unspecified cockpit
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was returning from modesto, ca airport on IFR flight plan to oak at sunset. I got instructions from bay approach to intercept the localizer for 27R at 4000' and gave traffic advisories. The WX was VFR, but the sun was setting and glaring off windshield so that I couldn't see traffic or airport (oak). Got distracted with traffic service and went through localizer. Immediately when I saw this I corrected. Approach questioned me about this and I indicated problem--was correcting. He gave me altitude 3000' to intercept ILS (I thought) and questioned me if I had visibility. Was not able to see runways at grove intersection when G/south came in, and I thought I had been cleared for approach, so I started descent with G/south. Approach came back and cleared me for 2500, then 2000' (I think), and I told him I had the airport. He then came back and said I had not been cleared for the approach and should not have descended. In hindsight, I do not remember actually being cleared for approach, but was anxious about the approach and not seeing the traffic that my listening skills were not good and I made an assumption rather than checking or verifying. Another problem I had was that the controller was short and I felt bad I had made the initial error about the intercept, so that my abilities were not as good as they would have been if wasn't feeling bad about the first mistake.

Original NASA ASRS Text

Title: PVT PLT FLEW THROUGH LOCALIZER, DESCENDED EARLY, BEFORE RECEIVING APCH CLRNC.

Narrative: I WAS RETURNING FROM MODESTO, CA ARPT ON IFR FLT PLAN TO OAK AT SUNSET. I GOT INSTRUCTIONS FROM BAY APCH TO INTERCEPT THE LOC FOR 27R AT 4000' AND GAVE TFC ADVISORIES. THE WX WAS VFR, BUT THE SUN WAS SETTING AND GLARING OFF WINDSHIELD SO THAT I COULDN'T SEE TFC OR ARPT (OAK). GOT DISTRACTED WITH TFC SVC AND WENT THROUGH LOC. IMMEDIATELY WHEN I SAW THIS I CORRECTED. APCH QUESTIONED ME ABOUT THIS AND I INDICATED PROB--WAS CORRECTING. HE GAVE ME ALT 3000' TO INTERCEPT ILS (I THOUGHT) AND QUESTIONED ME IF I HAD VIS. WAS NOT ABLE TO SEE RWYS AT GROVE INTXN WHEN G/S CAME IN, AND I THOUGHT I HAD BEEN CLRED FOR APCH, SO I STARTED DSNT WITH G/S. APCH CAME BACK AND CLRED ME FOR 2500, THEN 2000' (I THINK), AND I TOLD HIM I HAD THE ARPT. HE THEN CAME BACK AND SAID I HAD NOT BEEN CLRED FOR THE APCH AND SHOULD NOT HAVE DSNDED. IN HINDSIGHT, I DO NOT REMEMBER ACTUALLY BEING CLRED FOR APCH, BUT WAS ANXIOUS ABOUT THE APCH AND NOT SEEING THE TFC THAT MY LISTENING SKILLS WERE NOT GOOD AND I MADE AN ASSUMPTION RATHER THAN CHKING OR VERIFYING. ANOTHER PROB I HAD WAS THAT THE CTLR WAS SHORT AND I FELT BAD I HAD MADE THE INITIAL ERROR ABOUT THE INTERCEPT, SO THAT MY ABILITIES WERE NOT AS GOOD AS THEY WOULD HAVE BEEN IF WASN'T FEELING BAD ABOUT THE FIRST MISTAKE.

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.