ATC notes an altitude overshoot ultimately attributed to incorrect setting of the altimeter.

Attributes
ACN	565356
Time
Date	200211
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : egll.airport
State Reference	FO
Altitude	msl bound lower : 3700 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : egll.tracon
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time type : 3481
ASRS Report	565356
Person 2
Affiliation	company : air carrier
Function	flight crew : relief pilot
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Experience	flight time type : 4941
ASRS Report	565523
Events
Anomaly	altitude deviation : overshoot non adherence : published procedure non adherence : clearance non adherence : far
Independent Detector	other controllerb
Resolutory Action	controller : issued advisory flight crew : returned to assigned altitude flight crew : became reoriented
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On descent into egll, cleared out of flight levels to 4000 ft (local altimeter setting 1001 MB). Crew forgot to reset altimeters and leveled at FL040 (1013 MB) which was actually 3700 ft -- 300 ft low. Error was first noticed and immediately corrected when ATC questioned our altitude, asked us to check our altimeter setting, and said he showed us at 3700 ft. Supplemental information from acn 565523: the setting of qne was unintentionally not set and this lack of action was missed by all 3 pilots in the cockpit. Action was taken to correct altitude, ie, set altimeter 1001 MB. Approach was continued without further incidence. All SOP's were followed. Contributing factors: frequency congestion and all nighter fatigue.

Original NASA ASRS Text

Title: ATC NOTES AN ALT OVERSHOOT ULTIMATELY ATTRIBUTED TO INCORRECT SETTING OF THE ALTIMETER.

Narrative: ON DSCNT INTO EGLL, CLRED OUT OF FLT LEVELS TO 4000 FT (LCL ALTIMETER SETTING 1001 MB). CREW FORGOT TO RESET ALTIMETERS AND LEVELED AT FL040 (1013 MB) WHICH WAS ACTUALLY 3700 FT -- 300 FT LOW. ERROR WAS FIRST NOTICED AND IMMEDIATELY CORRECTED WHEN ATC QUESTIONED OUR ALT, ASKED US TO CHK OUR ALTIMETER SETTING, AND SAID HE SHOWED US AT 3700 FT. SUPPLEMENTAL INFO FROM ACN 565523: THE SETTING OF QNE WAS UNINTENTIONALLY NOT SET AND THIS LACK OF ACTION WAS MISSED BY ALL 3 PLTS IN THE COCKPIT. ACTION WAS TAKEN TO CORRECT ALT, IE, SET ALTIMETER 1001 MB. APCH WAS CONTINUED WITHOUT FURTHER INCIDENCE. ALL SOP'S WERE FOLLOWED. CONTRIBUTING FACTORS: FREQ CONGESTION AND ALL NIGHTER FATIGUE.

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.