B777 overshot its altitude when the data base does not switch over to its united states domestic sen...

Attributes
ACN	384745
Time
Date	199710
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : lrp
State Reference	PA
Altitude	msl bound lower : 16400 msl bound upper : 17000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny tracon : sju
Operator	common carrier : air carrier
Make Model Name	B777 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute airway : zny
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer pilot : commercial pilot : instrument
Experience	flight time last 90 days : 193 flight time total : 11152 flight time type : 674
ASRS Report	384745
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other controllera
Resolutory Action	flight crew : overcame equipment problem flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation other

Narrative:

Cleared to descend from FL200 to 17000 ft MSL. Set 17000 ft in mode control panel. As aircraft descended through 18000 ft I tried to set altimeter to 29.52 MB. Altitude indicator went yellow to alert us to an altimeter problem. Aircraft leveled off at 17000 ft indicated. Altimeter indication still yellow, selected VNAV climb page on CDU and discovered data base had not automatically switched from transition altitude of 6000 ft for london to 18000 ft for united states airspace. Entered '18000 ft,' altimeter went to normal indication and indicated we were at about 16400 ft. Immediately started climb back to 17000 ft, ZNY requested our indicated altitude, we replied we were having an altimeter problem with our automation and were climbing to 17000 ft. I have previously experienced this problem in the B777, but it has never before interfered with altimetry, the data base should not maintain 6000 ft transition altitude in the united states, period. Callback conversation with reporter revealed the following information: reporter's incident occurred on the one and only B777 in the fleet that has exhibited this characteristic. During descent the climb page sticks and stays in climb instead of shifting to the descent mode page. The flight had been at FL200 and was reclred to 17000 ft. The altimeter display gave a yellow warning of 'altitude not set correctly' indication when going through FL180. The altimeter wouldn't reset. The PIC went into the climb page and reset that page to 18000 ft. He then got a normal indication on his altimeters. He had descended to 16500 ft before ATC asked him about his problem. This has occurred numerous times and entered into the logbook each and every time. He doesn't now what his company is doing about it.

Original NASA ASRS Text

Title: B777 OVERSHOT ITS ALT WHEN THE DATA BASE DOES NOT SWITCH OVER TO ITS UNITED STATES DOMESTIC SENSING OF TRANSITION LEVEL OF 18000 FT. THE DATA BASE WAS 'STUCK' AT THE 6000 FT TRANSITION LEVEL AS UTILIZED IN THE UNITED KINGDOM, THE ACFT'S DEP POINT. ACFT LEVELED OFF SOME 600 FT BELOW ASSIGNED ALT. PIC HAD THIS OCCUR BEFORE, RECOGNIZED THE PROB AND RESET THE VNAV CLB DATA BASE TO 18000 FT.

Narrative: CLRED TO DSND FROM FL200 TO 17000 FT MSL. SET 17000 FT IN MODE CTL PANEL. AS ACFT DSNDED THROUGH 18000 FT I TRIED TO SET ALTIMETER TO 29.52 MB. ALT INDICATOR WENT YELLOW TO ALERT US TO AN ALTIMETER PROB. ACFT LEVELED OFF AT 17000 FT INDICATED. ALTIMETER INDICATION STILL YELLOW, SELECTED VNAV CLB PAGE ON CDU AND DISCOVERED DATA BASE HAD NOT AUTOMATICALLY SWITCHED FROM TRANSITION ALT OF 6000 FT FOR LONDON TO 18000 FT FOR UNITED STATES AIRSPACE. ENTERED '18000 FT,' ALTIMETER WENT TO NORMAL INDICATION AND INDICATED WE WERE AT ABOUT 16400 FT. IMMEDIATELY STARTED CLB BACK TO 17000 FT, ZNY REQUESTED OUR INDICATED ALT, WE REPLIED WE WERE HAVING AN ALTIMETER PROB WITH OUR AUTOMATION AND WERE CLBING TO 17000 FT. I HAVE PREVIOUSLY EXPERIENCED THIS PROB IN THE B777, BUT IT HAS NEVER BEFORE INTERFERED WITH ALTIMETRY, THE DATA BASE SHOULD NOT MAINTAIN 6000 FT TRANSITION ALT IN THE UNITED STATES, PERIOD. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR'S INCIDENT OCCURRED ON THE ONE AND ONLY B777 IN THE FLEET THAT HAS EXHIBITED THIS CHARACTERISTIC. DURING DSCNT THE CLB PAGE STICKS AND STAYS IN CLB INSTEAD OF SHIFTING TO THE DSCNT MODE PAGE. THE FLT HAD BEEN AT FL200 AND WAS RECLRED TO 17000 FT. THE ALTIMETER DISPLAY GAVE A YELLOW WARNING OF 'ALT NOT SET CORRECTLY' INDICATION WHEN GOING THROUGH FL180. THE ALTIMETER WOULDN'T RESET. THE PIC WENT INTO THE CLB PAGE AND RESET THAT PAGE TO 18000 FT. HE THEN GOT A NORMAL INDICATION ON HIS ALTIMETERS. HE HAD DSNDED TO 16500 FT BEFORE ATC ASKED HIM ABOUT HIS PROB. THIS HAS OCCURRED NUMEROUS TIMES AND ENTERED INTO THE LOGBOOK EACH AND EVERY TIME. HE DOESN'T NOW WHAT HIS COMPANY IS DOING ABOUT IT.

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.