B727 crew had track deviation.

Attributes
ACN	461634
Time
Date	200001
Day	Sun
Local Time Of Day	1801 To 2400
Place
State Reference	GA
Altitude	msl single value : 33000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	B727-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Route In Use	enroute airway : j43.airway
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : commercial pilot : instrument pilot : flight engineer pilot : multi engine
Experience	flight time last 90 days : 200 flight time total : 11000 flight time type : 6600
ASRS Report	461634
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : far other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance controller : issued advisory flight crew : returned to intended or assigned course none taken : detected after the fact
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

We were cruising on J43 between atl and szw when ZTL advised we were 12 mi east of course. Both vors were tuned to szw and set for 177 degree course and both showed precisely on centerline. ZTL gave vector to west and advised when we showed on track on their equipment. Both vors showed we were then 3 degrees right. ZTL asked what our course was, and we replied 177 degrees. ZTL thought it should be 179 degrees, which is correct for the route portion flown off atl VOR, but not szw. We checked NOTAMS and chart NOTAMS and could find no changes for J43 and therefore believe the VOR course selection was correct. We did note a significant buzz on the audio from szw that went away when another NAVAID was tuned. Had flight attendant check for possible unauthorized ped use. No unauthorized ped's were found, but VOR receivers both functioned normally for rest of flight.

Original NASA ASRS Text

Title: B727 CREW HAD TRACK DEV.

Narrative: WE WERE CRUISING ON J43 BTWN ATL AND SZW WHEN ZTL ADVISED WE WERE 12 MI E OF COURSE. BOTH VORS WERE TUNED TO SZW AND SET FOR 177 DEG COURSE AND BOTH SHOWED PRECISELY ON CTRLINE. ZTL GAVE VECTOR TO W AND ADVISED WHEN WE SHOWED ON TRACK ON THEIR EQUIP. BOTH VORS SHOWED WE WERE THEN 3 DEGS R. ZTL ASKED WHAT OUR COURSE WAS, AND WE REPLIED 177 DEGS. ZTL THOUGHT IT SHOULD BE 179 DEGS, WHICH IS CORRECT FOR THE RTE PORTION FLOWN OFF ATL VOR, BUT NOT SZW. WE CHKED NOTAMS AND CHART NOTAMS AND COULD FIND NO CHANGES FOR J43 AND THEREFORE BELIEVE THE VOR COURSE SELECTION WAS CORRECT. WE DID NOTE A SIGNIFICANT BUZZ ON THE AUDIO FROM SZW THAT WENT AWAY WHEN ANOTHER NAVAID WAS TUNED. HAD FLT ATTENDANT CHK FOR POSSIBLE UNAUTH PED USE. NO UNAUTH PED'S WERE FOUND, BUT VOR RECEIVERS BOTH FUNCTIONED NORMALLY FOR REST OF FLT.

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.