Heading track position deviation during an overwater operation.

Attributes
ACN	293520
Time
Date	199501
Day	Mon
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : einw
State Reference	FO
Altitude	msl bound lower : 41000 msl bound upper : 41000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : einn
Operator	general aviation : corporate
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 91
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : other oceanic enroute : atlantic
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 65 flight time total : 8700 flight time type : 65
ASRS Report	293520
Person 2
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Reported N54 W20 at air traffic area AM26Z, FL410, ETA N53 W15 at AM49Z, break just prior to N53 W15 shannon called us on UHF 135.6 and informed us we were off course by 38 mi north. We received his coordinates and compared them to our omega's. We showed we were no more than 5-6 mi north of course. On checking other navigation inputs (#1 IRS inputs and #2 IRS) on the #1 side showed us 35 mi left. #1 IRS inputs and #2 IRS on the right side showed us no more than 2 mi left. We took a heading from shannon and landed with no further comments. Plot at N54 W20 was N54.06 - W20.07 #1 side, N54.05 - W20.03 #2 side. This was not significant off course for concern. 3 navaids were showing plus or minus 5 mi off course and inbound to N53 W15. We were surprised that just prior to N53 W15 we were informed we were so far off course. At no time prior to N53 W15 including our recorded position at N54 W20 indicated we had to correct significant course deviation. No corrective action recommended. Maintenance is checking navaids for problems. We will flight check navaids for deviations. All pilots will be informed and updated on current long range navigation.

Original NASA ASRS Text

Title: HDG TRACK POS DEV DURING AN OVERWATER OP.

Narrative: RPTED N54 W20 AT ATA AM26Z, FL410, ETA N53 W15 AT AM49Z, BREAK JUST PRIOR TO N53 W15 SHANNON CALLED US ON UHF 135.6 AND INFORMED US WE WERE OFF COURSE BY 38 MI N. WE RECEIVED HIS COORDINATES AND COMPARED THEM TO OUR OMEGA'S. WE SHOWED WE WERE NO MORE THAN 5-6 MI N OF COURSE. ON CHKING OTHER NAV INPUTS (#1 IRS INPUTS AND #2 IRS) ON THE #1 SIDE SHOWED US 35 MI L. #1 IRS INPUTS AND #2 IRS ON THE R SIDE SHOWED US NO MORE THAN 2 MI L. WE TOOK A HDG FROM SHANNON AND LANDED WITH NO FURTHER COMMENTS. PLOT AT N54 W20 WAS N54.06 - W20.07 #1 SIDE, N54.05 - W20.03 #2 SIDE. THIS WAS NOT SIGNIFICANT OFF COURSE FOR CONCERN. 3 NAVAIDS WERE SHOWING PLUS OR MINUS 5 MI OFF COURSE AND INBOUND TO N53 W15. WE WERE SURPRISED THAT JUST PRIOR TO N53 W15 WE WERE INFORMED WE WERE SO FAR OFF COURSE. AT NO TIME PRIOR TO N53 W15 INCLUDING OUR RECORDED POS AT N54 W20 INDICATED WE HAD TO CORRECT SIGNIFICANT COURSE DEV. NO CORRECTIVE ACTION RECOMMENDED. MAINT IS CHKING NAVAIDS FOR PROBS. WE WILL FLT CHK NAVAIDS FOR DEVS. ALL PLTS WILL BE INFORMED AND UPDATED ON CURRENT LONG RANGE NAV.

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.