B767 flight crew has EICAS warning of left bleed duct leak. Decision to return to departure airport.

Attributes
ACN	391352
Time
Date	199801
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : egtt
State Reference	FO
Aircraft 1
Controlling Facilities	artcc : egtt
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude other other
Route In Use	enroute : atlantic
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	391352
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

ATC facility: london. Location: ireland. Approximately 40 mins after takeoff we had a left bleed duct leak, EICAS message with aural warning. Abnormal procedure completed. Light extinguished and my analysis was that we did have a potential leak and the system could not be returned to normal. Decision made to return to lhr, reviewed all overweight procedures and requirements, communicated with company dispatch and maintenance. Requested expedited handling from london control and crash fire rescue equipment equipment. During this time we descended to a lower altitude and increased our fuel flow with confign to reduce the landing weight as much as possible during this time. Landing weight 370000 pounds.

Original NASA ASRS Text

Title: B767 FLC HAS EICAS WARNING OF L BLEED DUCT LEAK. DECISION TO RETURN TO DEP ARPT.

Narrative: ATC FACILITY: LONDON. LOCATION: IRELAND. APPROX 40 MINS AFTER TKOF WE HAD A L BLEED DUCT LEAK, EICAS MESSAGE WITH AURAL WARNING. ABNORMAL PROC COMPLETED. LIGHT EXTINGUISHED AND MY ANALYSIS WAS THAT WE DID HAVE A POTENTIAL LEAK AND THE SYS COULD NOT BE RETURNED TO NORMAL. DECISION MADE TO RETURN TO LHR, REVIEWED ALL OVERWT PROCS AND REQUIREMENTS, COMMUNICATED WITH COMPANY DISPATCH AND MAINT. REQUESTED EXPEDITED HANDLING FROM LONDON CTL AND CFR EQUIP. DURING THIS TIME WE DSNDED TO A LOWER ALT AND INCREASED OUR FUEL FLOW WITH CONFIGN TO REDUCE THE LNDG WT AS MUCH AS POSSIBLE DURING THIS TIME. LNDG WT 370000 LBS.

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.