B767-300 captain reports map shift at iad following long distance flight.

Attributes
ACN	762971
Time
Date	200711
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : iad.airport
State Reference	DC
Altitude	msl single value : 3000
Environment
Flight Conditions	VMC
Aircraft 1
Controlling Facilities	tower : iad.tower
Operator	common carrier : air carrier
Make Model Name	B767-300 and 300 ER
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 18500 flight time type : 4500
ASRS Report	762971
Events
Anomaly	aircraft equipment problem : less severe other spatial deviation
Independent Detector	aircraft equipment : altitude alert other flight crewa
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	Flight Crew Human Performance Navigational Facility Aircraft
Primary Problem	Aircraft

Narrative:

We were on a visual approach to iad runway 19L; after a runway change due to flight Z going around from a misaligned approach to runway 1R. On downwind to runway 19L we reported the airport in sight and received and acknowledged clearance for visual to runway 19L; maintain 3000 ft until base and call tower. I turned base approximately 5 mi and had first officer extend runway 19L on the legs page. I was using the FMC data to properly align for final approach. The first officer picked up the runway after I had undershot runway 19L while following the FMC generated picture as I did not have the runway in sight. I disconnected the autoplt and aligned the aircraft with runway 19L. At this time we noticed a map shift of approximately 3 mi. I continued with all configns and checklists and was stabilized at approximately 800 ft AGL. At 500 ft AGL we received 'too low gear; GS; GS and go around commands.' we (3 pilots) confirmed proper confign and profile and continued to a landing. I attributed the commands to map shift. I asked tower to notify flight Y of the map shift; and in the crew room they experienced the same event. I believe flight Z also had a map shift; thereby causing his misalignment and go around. For 3 company aircraft returning to iad after 10 hour flts and all experiencing map shift at the airport seems unusual. The FMC computed display had been accurate the entire flight since departure from ZZZ.

Original NASA ASRS Text

Title: B767-300 CAPTAIN REPORTS MAP SHIFT AT IAD FOLLOWING LONG DISTANCE FLT.

Narrative: WE WERE ON A VISUAL APCH TO IAD RWY 19L; AFTER A RWY CHANGE DUE TO FLT Z GOING AROUND FROM A MISALIGNED APCH TO RWY 1R. ON DOWNWIND TO RWY 19L WE RPTED THE ARPT IN SIGHT AND RECEIVED AND ACKNOWLEDGED CLRNC FOR VISUAL TO RWY 19L; MAINTAIN 3000 FT UNTIL BASE AND CALL TWR. I TURNED BASE APPROX 5 MI AND HAD FO EXTEND RWY 19L ON THE LEGS PAGE. I WAS USING THE FMC DATA TO PROPERLY ALIGN FOR FINAL APCH. THE FO PICKED UP THE RWY AFTER I HAD UNDERSHOT RWY 19L WHILE FOLLOWING THE FMC GENERATED PICTURE AS I DID NOT HAVE THE RWY IN SIGHT. I DISCONNECTED THE AUTOPLT AND ALIGNED THE ACFT WITH RWY 19L. AT THIS TIME WE NOTICED A MAP SHIFT OF APPROX 3 MI. I CONTINUED WITH ALL CONFIGNS AND CHKLISTS AND WAS STABILIZED AT APPROX 800 FT AGL. AT 500 FT AGL WE RECEIVED 'TOO LOW GEAR; GS; GS AND GAR COMMANDS.' WE (3 PLTS) CONFIRMED PROPER CONFIGN AND PROFILE AND CONTINUED TO A LNDG. I ATTRIBUTED THE COMMANDS TO MAP SHIFT. I ASKED TWR TO NOTIFY FLT Y OF THE MAP SHIFT; AND IN THE CREW ROOM THEY EXPERIENCED THE SAME EVENT. I BELIEVE FLT Z ALSO HAD A MAP SHIFT; THEREBY CAUSING HIS MISALIGNMENT AND GAR. FOR 3 COMPANY ACFT RETURNING TO IAD AFTER 10 HR FLTS AND ALL EXPERIENCING MAP SHIFT AT THE ARPT SEEMS UNUSUAL. THE FMC COMPUTED DISPLAY HAD BEEN ACCURATE THE ENTIRE FLT SINCE DEP FROM ZZZ.

Data retrieved from NASA's ASRS site as of January 2009 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.