Air carrier widebody transport deviated from clearance route in northern canada.

Attributes
ACN	109384
Time
Date	198904
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : yvp
State Reference	PQ
Altitude	msl bound lower : 35000 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : czul
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : atlantic enroute airway : na364
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 20000 flight time type : 4000
ASRS Report	109384
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer pilot : cfi
Experience	flight time last 90 days : 235 flight time total : 5000 flight time type : 775
ASRS Report	109462
Events
Anomaly	non adherence : clearance other spatial deviation
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We reported over the fix lumbr (58N/70W) with an estimate for cyril 50 460N/80W, 557 NM) of 40 mins after passing lumbr. Cymx questioned our estimate. We checked our computer flight plan which we had used to program our INS and ONS units and it showed cyril as 56 460N--thus the error. Our computer flight plan showed 333 NM lumbr to cyril and not the correct arwy (NA364), since we were heading for 56N instead of 50N. This required reprogramming both INS units and the ONS unit with the proper coordinate. If cymx had not questioned the estimate we certainly would have infringed on another arwy/route. It is the airline procedure to check computer coordinate against chart coordinates, but something broke the chain of our normal procedures today and allowed the error to go unnoticed. There is no radar coverage in the area and the heading we had programmed would have taken us across several arwys/routes (also west/O radar coverage). A double check of chart verses computer positions is a must. Some human programmed the error and we humans did not follow complete procedures and so it got by us.

Original NASA ASRS Text

Title: ACR WDB DEVIATED FROM CLRNC ROUTE IN NORTHERN CANADA.

Narrative: WE RPTED OVER THE FIX LUMBR (58N/70W) WITH AN ESTIMATE FOR CYRIL 50 460N/80W, 557 NM) OF 40 MINS AFTER PASSING LUMBR. CYMX QUESTIONED OUR ESTIMATE. WE CHKED OUR COMPUTER FLT PLAN WHICH WE HAD USED TO PROGRAM OUR INS AND ONS UNITS AND IT SHOWED CYRIL AS 56 460N--THUS THE ERROR. OUR COMPUTER FLT PLAN SHOWED 333 NM LUMBR TO CYRIL AND NOT THE CORRECT ARWY (NA364), SINCE WE WERE HDG FOR 56N INSTEAD OF 50N. THIS REQUIRED REPROGRAMMING BOTH INS UNITS AND THE ONS UNIT WITH THE PROPER COORDINATE. IF CYMX HAD NOT QUESTIONED THE ESTIMATE WE CERTAINLY WOULD HAVE INFRINGED ON ANOTHER ARWY/ROUTE. IT IS THE AIRLINE PROC TO CHK COMPUTER COORDINATE AGAINST CHART COORDINATES, BUT SOMETHING BROKE THE CHAIN OF OUR NORMAL PROCS TODAY AND ALLOWED THE ERROR TO GO UNNOTICED. THERE IS NO RADAR COVERAGE IN THE AREA AND THE HDG WE HAD PROGRAMMED WOULD HAVE TAKEN US ACROSS SEVERAL ARWYS/ROUTES (ALSO W/O RADAR COVERAGE). A DOUBLE CHK OF CHART VERSES COMPUTER POSITIONS IS A MUST. SOME HUMAN PROGRAMMED THE ERROR AND WE HUMANS DID NOT FOLLOW COMPLETE PROCS AND SO IT GOT BY US.

Data retrieved from NASA's ASRS site as of August 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.