Small aircraft pilot descends below MDA on localizer DME runway 28L at hwd.

Attributes
ACN	132113
Time
Date	198912
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : mwd airport : hwd
State Reference	CA
Altitude	msl bound lower : 300 msl bound upper : 400
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : hwd
Operator	general aviation : personal
Make Model Name	Small Aircraft, High Wing, 1 Eng, Fixed Gear
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 810 flight time type : 300
ASRS Report	132113
Person 2
Affiliation	government : faa
Function	controller : local
Qualification	controller : non radar
Events
Anomaly	altitude deviation : overshoot non adherence : published procedure other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Hayward ATIS was reporting 300 ovc because of fog. The ovc was dropping rapidly. I shot the localizer DME 28L approach into hwd. The MDA for the approach is 400 MSL. The map is 0.9 DME on the localizer frequency. During the approach I asked hayward tower how the plane just ahead of me completed the approach. He said the plane had trouble seeing the runway. As I shot the approach at 0.9 DME and 400' MSL, I could not see the airport. The tower asked if I could see the mall just east of the runway. I said negative. While I was looking down for landmarks and the runway environment, I descended below the MDA (400'). Shortly after 0.9 DME I saw the approach end of the runway and did a circle to land. At the MDA and map I should have done the missed instead of relying on visual cues. Switching from instruments to looking outside to the ground caused me to bust the MDA. Next time I will not go any further down if I don't have any runway environment in sight. This was a very scary and stupid experience.

Original NASA ASRS Text

Title: SMA PLT DESCENDS BELOW MDA ON LOC DME RWY 28L AT HWD.

Narrative: HAYWARD ATIS WAS REPORTING 300 OVC BECAUSE OF FOG. THE OVC WAS DROPPING RAPIDLY. I SHOT THE LOC DME 28L APCH INTO HWD. THE MDA FOR THE APCH IS 400 MSL. THE MAP IS 0.9 DME ON THE LOC FREQ. DURING THE APCH I ASKED HAYWARD TWR HOW THE PLANE JUST AHEAD OF ME COMPLETED THE APCH. HE SAID THE PLANE HAD TROUBLE SEEING THE RWY. AS I SHOT THE APCH AT 0.9 DME AND 400' MSL, I COULD NOT SEE THE ARPT. THE TWR ASKED IF I COULD SEE THE MALL JUST E OF THE RWY. I SAID NEGATIVE. WHILE I WAS LOOKING DOWN FOR LANDMARKS AND THE RWY ENVIRONMENT, I DESCENDED BELOW THE MDA (400'). SHORTLY AFTER 0.9 DME I SAW THE APCH END OF THE RWY AND DID A CIRCLE TO LAND. AT THE MDA AND MAP I SHOULD HAVE DONE THE MISSED INSTEAD OF RELYING ON VISUAL CUES. SWITCHING FROM INSTRUMENTS TO LOOKING OUTSIDE TO THE GND CAUSED ME TO BUST THE MDA. NEXT TIME I WILL NOT GO ANY FURTHER DOWN IF I DON'T HAVE ANY RWY ENVIRONMENT IN SIGHT. THIS WAS A VERY SCARY AND STUPID EXPERIENCE.

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.