A PA31 atx pilot descends prematurely to the MDA for the approach when cleared down to 3000 ft near ...

Attributes
ACN	407090
Time
Date	199806
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : myf
State Reference	CA
Altitude	msl bound lower : 2000 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : san tracon : sgf
Operator	common carrier : air taxi
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	descent : approach descent other
Route In Use	arrival other enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 280 flight time total : 2800 flight time type : 260
ASRS Report	407090
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : published procedure non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course flight crew : became reoriented other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While being vectored for approach, was instructed to descend and maintain 3000 ft, down from 5000 ft. While descending, was given vector normally given on this approach to intercept localizer. I proceeded to the MDA at this point, although not cleared to do so. I caught my error and proceeded back up and ATC also advised me of my error. I was on an IFR flight plan, although I was above the IFR conditions and clear visibility at the time of occurrence. I believe that complacency due to flying the same route for 5 months and usually being cleared down caused this situation to occur. Fatigue was also a factor. Nobody is to blame except for the PIC in this incident.

Original NASA ASRS Text

Title: A PA31 ATX PLT DSNDS PREMATURELY TO THE MDA FOR THE APCH WHEN CLRED DOWN TO 3000 FT NEAR MYF ARPT.

Narrative: WHILE BEING VECTORED FOR APCH, WAS INSTRUCTED TO DSND AND MAINTAIN 3000 FT, DOWN FROM 5000 FT. WHILE DSNDING, WAS GIVEN VECTOR NORMALLY GIVEN ON THIS APCH TO INTERCEPT LOC. I PROCEEDED TO THE MDA AT THIS POINT, ALTHOUGH NOT CLRED TO DO SO. I CAUGHT MY ERROR AND PROCEEDED BACK UP AND ATC ALSO ADVISED ME OF MY ERROR. I WAS ON AN IFR FLT PLAN, ALTHOUGH I WAS ABOVE THE IFR CONDITIONS AND CLR VISIBILITY AT THE TIME OF OCCURRENCE. I BELIEVE THAT COMPLACENCY DUE TO FLYING THE SAME RTE FOR 5 MONTHS AND USUALLY BEING CLRED DOWN CAUSED THIS SIT TO OCCUR. FATIGUE WAS ALSO A FACTOR. NOBODY IS TO BLAME EXCEPT FOR THE PIC IN THIS INCIDENT.

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 PA31 atx pilot descends prematurely to the MDA for the approach when cleared down to 3000 ft near myf airport.