Flight crew gets over 30 mi off course.

Attributes
ACN	308940
Time
Date	199506
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : jhw
State Reference	NY
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zob
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	308940
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : cfi pilot : flight engineer
Events
Anomaly	aircraft equipment problem : less severe inflight encounter : weather non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

En route from dfw to bos, ONS (omega navigation system) departure area check accomplished and was satisfactory. ONS used till approximately jhw (jamestown VOR). Heading used for deviations around WX. ONS appeared to be functioning fine till vicinity of jhw. Cleveland asked if we were on a heading or not, we said a direct jhw was issued. The controller advised us of being off by some 30 or so mi southeast. Prior to that I was going over the approach plates and airport diagrams for bos and my attention was diverted for a bit. My first officer was flying. So I am not sure how much ONS error and just coming out of deviating around WX was to blame. Net result no problems, no conflicts, the controller gave us direct to albany the rest of the flight was VOR only with no problems. An accuracy check at the gate in bos showed a 34.5 NM error. Performance of omega system for 2 days previous was satisfactory even with the jun warning of omega errors. This occurred around 0048Z, FL290 I believe.

Original NASA ASRS Text

Title: FLC GETS OVER 30 MI OFF COURSE.

Narrative: ENRTE FROM DFW TO BOS, ONS (OMEGA NAV SYS) DEP AREA CHK ACCOMPLISHED AND WAS SATISFACTORY. ONS USED TILL APPROX JHW (JAMESTOWN VOR). HDG USED FOR DEVS AROUND WX. ONS APPEARED TO BE FUNCTIONING FINE TILL VICINITY OF JHW. CLEVELAND ASKED IF WE WERE ON A HDG OR NOT, WE SAID A DIRECT JHW WAS ISSUED. THE CTLR ADVISED US OF BEING OFF BY SOME 30 OR SO MI SE. PRIOR TO THAT I WAS GOING OVER THE APCH PLATES AND ARPT DIAGRAMS FOR BOS AND MY ATTN WAS DIVERTED FOR A BIT. MY FO WAS FLYING. SO I AM NOT SURE HOW MUCH ONS ERROR AND JUST COMING OUT OF DEVIATING AROUND WX WAS TO BLAME. NET RESULT NO PROBS, NO CONFLICTS, THE CTLR GAVE US DIRECT TO ALBANY THE REST OF THE FLT WAS VOR ONLY WITH NO PROBS. AN ACCURACY CHK AT THE GATE IN BOS SHOWED A 34.5 NM ERROR. PERFORMANCE OF OMEGA SYS FOR 2 DAYS PREVIOUS WAS SATISFACTORY EVEN WITH THE JUN WARNING OF OMEGA ERRORS. THIS OCCURRED AROUND 0048Z, FL290 I BELIEVE.

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.