Descent below published on VOR approach triggers altitude alert.

Attributes
ACN	275947
Time
Date	199407
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sba
State Reference	CA
Altitude	msl bound lower : 1100 msl bound upper : 2100
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sba
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent : approach descent other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 12 flight time total : 1300 flight time type : 200
ASRS Report	275947
Person 2
Affiliation	Other
Function	observation : observer
Qualification	pilot : instrument pilot : private
Events
Anomaly	non adherence : published procedure non adherence : clearance other spatial deviation
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	flight crew : became reoriented flight crew : returned to intended course or assigned course
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During the course of executing the VOR approach to sba I was descending toward zacks intersection which has a minimum altitude of 2100 ft. I misread my altimeter and went down to 1100 ft which triggered an altitude alert. The controller so advised and ordered an immediate climb back to 2100 ft which I complied with. I think a contributing factor was that I was having trouble with a headset and microphone (an intermittent transmission) which diverted my attention and I passed right on through 2100 ft. The lesson is, don't be diverted due to events such as malfunctions. This was an instrument proficiency flight with another instrument pilot as safety pilot. Both of us missed the altitude deviation since he was looking through the haze to see the field when it appeared.

Original NASA ASRS Text

Title: DSCNT BELOW PUBLISHED ON VOR APCH TRIGGERS ALT ALERT.

Narrative: DURING THE COURSE OF EXECUTING THE VOR APCH TO SBA I WAS DSNDING TOWARD ZACKS INTXN WHICH HAS A MINIMUM ALT OF 2100 FT. I MISREAD MY ALTIMETER AND WENT DOWN TO 1100 FT WHICH TRIGGERED AN ALT ALERT. THE CTLR SO ADVISED AND ORDERED AN IMMEDIATE CLB BACK TO 2100 FT WHICH I COMPLIED WITH. I THINK A CONTRIBUTING FACTOR WAS THAT I WAS HAVING TROUBLE WITH A HEADSET AND MIKE (AN INTERMITTENT XMISSION) WHICH DIVERTED MY ATTN AND I PASSED RIGHT ON THROUGH 2100 FT. THE LESSON IS, DON'T BE DIVERTED DUE TO EVENTS SUCH AS MALFUNCTIONS. THIS WAS AN INST PROFICIENCY FLT WITH ANOTHER INST PLT AS SAFETY PLT. BOTH OF US MISSED THE ALTDEV SINCE HE WAS LOOKING THROUGH THE HAZE TO SEE THE FIELD WHEN IT APPEARED.

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.