SR22 pilot on IFR flight plan alters course towards expected approach IAF without clearance to do so...

Attributes
ACN	794737
Time
Date	200807
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ocw.airport
State Reference	NC
Altitude	msl single value : 2000
Environment
Flight Conditions	IMC
Weather Elements	Rain
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc.artcc
Operator	general aviation : personal
Make Model Name	SR22
Operating Under FAR Part	Part 91
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	approach : visual
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : cfi
Experience	flight time last 90 days : 120 flight time total : 1400 flight time type : 200
ASRS Report	794737
Person 2
Affiliation	government : faa
Function	controller : radar
Events
Anomaly	non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued advisory
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	ATC Human Performance Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was IFR descending into ocw (washington warren field). I was told to expect the visual. Since I was already close to the IAF decoi I set the approach in the GPS and hit activate. The aircraft turned 10 degrees to the right; intercepted the IAF then turned left. On the approach ATC called and asked why I had turned and I told the controller that I had activated the approach. Controller then started to tell me that I couldn't turn or do the approach unless I was told I could. The WX was 800 ft scattered 1300 ft scattered and I was currently IMC. So I thought I should have the help of the GPS to be able to find the airport based on the current WX conditions. I should have asked first before doing anything!

Original NASA ASRS Text

Title: SR22 PLT ON IFR FLT PLAN ALTERS COURSE TOWARDS EXPECTED APCH IAF WITHOUT CLRNC TO DO SO.

Narrative: I WAS IFR DSNDING INTO OCW (WASHINGTON WARREN FIELD). I WAS TOLD TO EXPECT THE VISUAL. SINCE I WAS ALREADY CLOSE TO THE IAF DECOI I SET THE APCH IN THE GPS AND HIT ACTIVATE. THE ACFT TURNED 10 DEGS TO THE R; INTERCEPTED THE IAF THEN TURNED L. ON THE APCH ATC CALLED AND ASKED WHY I HAD TURNED AND I TOLD THE CTLR THAT I HAD ACTIVATED THE APCH. CTLR THEN STARTED TO TELL ME THAT I COULDN'T TURN OR DO THE APCH UNLESS I WAS TOLD I COULD. THE WX WAS 800 FT SCATTERED 1300 FT SCATTERED AND I WAS CURRENTLY IMC. SO I THOUGHT I SHOULD HAVE THE HELP OF THE GPS TO BE ABLE TO FIND THE ARPT BASED ON THE CURRENT WX CONDITIONS. I SHOULD HAVE ASKED FIRST BEFORE DOING ANYTHING!

Data retrieved from NASA's ASRS site as of May 2009 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.