Heading track deviation in a non adherence to ATC clearance.

Attributes
ACN	246977
Time
Date	199307
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : mer
State Reference	CA
Altitude	msl bound lower : 7500 msl bound upper : 7500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : mer
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Retractable Gear
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : private
Experience	flight time last 90 days : 27 flight time total : 348 flight time type : 30
ASRS Report	246977
Person 2
Affiliation	government : military
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

En route from sac to hmt on IFR flight plan and clearance. VFR on top at 7500 ft, WX ceiling and visibility unlimited. Routing on clearance called for V23 from linden VOR to shafter VOR. During my IFR training, I was told that declaring 'VFR on top' allowed direct routing at pilot's discretion. I can recall specific examples my cfii gave. As a result, I opted to depart linden direct el nido direct shafter. I didn't request an amended clearance or advise ATC, not believing it to be needed/required. Castle approach questioned my routing after I was off my assigned route and I advised them of my intentions. Approach advised that I was required to fly the routing in my clearance. Castle then amended my clearance to allow me to proceed direct shafter. I would never knowingly violate the FARS, but neither have I read them and the aim cover to cover and word for word. I have relied, at least in part, on the information imparted to me by instructors. I guess I will have to be more skeptical and do more personal research into these issues in the future.

Original NASA ASRS Text

Title: HDG TRACK DEV IN A NON ADHERENCE TO ATC CLRNC.

Narrative: ENRTE FROM SAC TO HMT ON IFR FLT PLAN AND CLRNC. VFR ON TOP AT 7500 FT, WX CEILING AND VISIBILITY UNLIMITED. ROUTING ON CLRNC CALLED FOR V23 FROM LINDEN VOR TO SHAFTER VOR. DURING MY IFR TRAINING, I WAS TOLD THAT DECLARING 'VFR ON TOP' ALLOWED DIRECT ROUTING AT PLT'S DISCRETION. I CAN RECALL SPECIFIC EXAMPLES MY CFII GAVE. AS A RESULT, I OPTED TO DEPART LINDEN DIRECT EL NIDO DIRECT SHAFTER. I DIDN'T REQUEST AN AMENDED CLRNC OR ADVISE ATC, NOT BELIEVING IT TO BE NEEDED/REQUIRED. CASTLE APCH QUESTIONED MY ROUTING AFTER I WAS OFF MY ASSIGNED RTE AND I ADVISED THEM OF MY INTENTIONS. APCH ADVISED THAT I WAS REQUIRED TO FLY THE ROUTING IN MY CLRNC. CASTLE THEN AMENDED MY CLRNC TO ALLOW ME TO PROCEED DIRECT SHAFTER. I WOULD NEVER KNOWINGLY VIOLATE THE FARS, BUT NEITHER HAVE I READ THEM AND THE AIM COVER TO COVER AND WORD FOR WORD. I HAVE RELIED, AT LEAST IN PART, ON THE INFO IMPARTED TO ME BY INSTRUCTORS. I GUESS I WILL HAVE TO BE MORE SKEPTICAL AND DO MORE PERSONAL RESEARCH INTO THESE ISSUES IN THE FUTURE.

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.