Reporter cites transient unreliability with dg as cause for track deviation.

Attributes
ACN	152823
Time
Date	199007
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : btv
State Reference	VT
Altitude	msl bound lower : 4000 msl bound upper : 4000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Operator	general aviation : personal
Make Model Name	Small Aircraft, Low Wing, 1 Eng, Fixed Gear
Flight Phase	cruise other
Route In Use	enroute airway : v91
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 15 flight time total : 601 flight time type : 300
ASRS Report	152823
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	aircraft equipment problem : less severe inflight encounter : weather non adherence : clearance other anomaly other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance flight crew : regained aircraft control other
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was proceeding north to burling to airport from rutland, vt, airport left rut VFR. About 25 mi out WX started to deteriorate. I had called approach before and received squawk code. I called approach for IFR clearance. He gave me one, join V91, 4000'. As I was turning to join V91 my dg started to act erratically, and I proceeded through arwy. Controller issued vector and I turned in the wrong direction due to dg erratic operation. Controller then issued no gyro vectors and got me back on track. Dg seemed to come back and I finished approach. At no time to my knowledge was there any conflict with any other aircraft. Upon landing, controller asked me to call shift supervisor which I did. I idented myself by my north number and told him I had gyro problems, he said that's what he thought and was just checking to make sure everything was all right. He also asked if I was IFR rated. He said have a good day. He never asked for my name so I assume this would be the end of it.

Original NASA ASRS Text

Title: REPORTER CITES TRANSIENT UNRELIABILITY WITH DG AS CAUSE FOR TRACK DEVIATION.

Narrative: I WAS PROCEEDING N TO BURLING TO ARPT FROM RUTLAND, VT, ARPT L RUT VFR. ABOUT 25 MI OUT WX STARTED TO DETERIORATE. I HAD CALLED APCH BEFORE AND RECEIVED SQUAWK CODE. I CALLED APCH FOR IFR CLRNC. HE GAVE ME ONE, JOIN V91, 4000'. AS I WAS TURNING TO JOIN V91 MY DG STARTED TO ACT ERRATICALLY, AND I PROCEEDED THROUGH ARWY. CTLR ISSUED VECTOR AND I TURNED IN THE WRONG DIRECTION DUE TO DG ERRATIC OPERATION. CTLR THEN ISSUED NO GYRO VECTORS AND GOT ME BACK ON TRACK. DG SEEMED TO COME BACK AND I FINISHED APCH. AT NO TIME TO MY KNOWLEDGE WAS THERE ANY CONFLICT WITH ANY OTHER ACFT. UPON LNDG, CTLR ASKED ME TO CALL SHIFT SUPVR WHICH I DID. I IDENTED MYSELF BY MY N NUMBER AND TOLD HIM I HAD GYRO PROBS, HE SAID THAT'S WHAT HE THOUGHT AND WAS JUST CHKING TO MAKE SURE EVERYTHING WAS ALL RIGHT. HE ALSO ASKED IF I WAS IFR RATED. HE SAID HAVE A GOOD DAY. HE NEVER ASKED FOR MY NAME SO I ASSUME THIS WOULD BE THE END OF IT.

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.