DC10 crew had gross navigation error in rjtg airspace.

Attributes
ACN	451460
Time
Date	199910
Day	Thu
Local Time Of Day	0001 To 0600
Place
Locale Reference	intersection : bubdo
State Reference	FO
Altitude	msl single value : 29000
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Controlling Facilities	artcc : rjtg.artcc
Operator	common carrier : air carrier
Make Model Name	DC-10 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level
Route In Use	enroute : pacific enroute airway : a590.airway
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine pilot : flight engineer
Experience	flight time last 90 days : 150 flight time total : 4000 flight time type : 700
ASRS Report	451460
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe non adherence : published procedure non adherence : clearance non adherence : company policies non adherence : far other spatial deviation
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended or assigned course flight crew : returned to original clearance
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On descent, we discovered a problem with the mechanical digital readout of our heading selector. During cruise, while the autoplt was receiving navigation guidance from the INS, the captain and flight engineer did some troubleshooting of the problem so that an aml entry could be made. During this process, apparently the heading selector knob was pushed in, causing the aircraft to go into heading hold. As the PF, I did not recognize this. Over time, due to changing winds and variation, we drifted left of course. The flight engineer actually noticed this noting that the CDI bar was not centered. At that time I realized we were in heading hold. We immediately corrected back to the airway. I estimate that we were approximately 20 mi off course. It is very easy to become complacent toward navigation when you operate with a good autoplt and INS. When you couple it up, it flies the route very precisely. In the future, I will ensure that the aircraft is still in the planned mode after anyone touches any type autoplt control. I will also try to be more vigilant as the PF to the flight mode annunciators during cruise. I take a lot of pains to stay on top of navigation, using charts and navaids, but out over water this error slipped by me.

Original NASA ASRS Text

Title: DC10 CREW HAD GROSS NAV ERROR IN RJTG AIRSPACE.

Narrative: ON DSCNT, WE DISCOVERED A PROB WITH THE MECHANICAL DIGITAL READOUT OF OUR HDG SELECTOR. DURING CRUISE, WHILE THE AUTOPLT WAS RECEIVING NAV GUIDANCE FROM THE INS, THE CAPT AND FE DID SOME TROUBLESHOOTING OF THE PROB SO THAT AN AML ENTRY COULD BE MADE. DURING THIS PROCESS, APPARENTLY THE HDG SELECTOR KNOB WAS PUSHED IN, CAUSING THE ACFT TO GO INTO HDG HOLD. AS THE PF, I DID NOT RECOGNIZE THIS. OVER TIME, DUE TO CHANGING WINDS AND VARIATION, WE DRIFTED L OF COURSE. THE FE ACTUALLY NOTICED THIS NOTING THAT THE CDI BAR WAS NOT CTRED. AT THAT TIME I REALIZED WE WERE IN HDG HOLD. WE IMMEDIATELY CORRECTED BACK TO THE AIRWAY. I ESTIMATE THAT WE WERE APPROX 20 MI OFF COURSE. IT IS VERY EASY TO BECOME COMPLACENT TOWARD NAV WHEN YOU OPERATE WITH A GOOD AUTOPLT AND INS. WHEN YOU COUPLE IT UP, IT FLIES THE RTE VERY PRECISELY. IN THE FUTURE, I WILL ENSURE THAT THE ACFT IS STILL IN THE PLANNED MODE AFTER ANYONE TOUCHES ANY TYPE AUTOPLT CTL. I WILL ALSO TRY TO BE MORE VIGILANT AS THE PF TO THE FLT MODE ANNUNCIATORS DURING CRUISE. I TAKE A LOT OF PAINS TO STAY ON TOP OF NAV, USING CHARTS AND NAVAIDS, BUT OUT OVER WATER THIS ERROR SLIPPED BY ME.

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.