Precautionary landing due to erratic engine indications.

Attributes
ACN	129056
Time
Date	198911
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : bcn
State Reference	FO
Altitude	msl bound lower : 35000 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : egtt tower : pmp
Operator	common carrier : air carrier
Make Model Name	Heavy Transport, Low Wing, 4 Turbojet Eng
Flight Phase	cruise other cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp pilot : cfi
Experience	flight time last 90 days : 120 flight time total : 7095 flight time type : 700
ASRS Report	129056
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	other

Narrative:

We climbed from FL310 to FL350 preparing for our atlantic crossing (original routing athens to newark). On leveling at FL350, F/east noted that with all 4 engine EPR's matched up, #4 engine was suddenly running 10% higher N1 and N2 speeds, a higher egt, and the fuel flow was now 1000 pounds per hour higher than the other 3 engines. We tried to troubleshoot (cycling bleeds, moving throttle, etc), but no improvement. We decided that at the increased fuel flow we would cut into our fuel reserves. Also the engine health was questionable, so captain elected to divert for a precautionary landing at stansted, england. Kept #4 at reduced power. Normal landing, no further problems.

Original NASA ASRS Text

Title: PRECAUTIONARY LNDG DUE TO ERRATIC ENGINE INDICATIONS.

Narrative: WE CLBED FROM FL310 TO FL350 PREPARING FOR OUR ATLANTIC XING (ORIGINAL ROUTING ATHENS TO NEWARK). ON LEVELING AT FL350, F/E NOTED THAT WITH ALL 4 ENG EPR'S MATCHED UP, #4 ENG WAS SUDDENLY RUNNING 10% HIGHER N1 AND N2 SPDS, A HIGHER EGT, AND THE FUEL FLOW WAS NOW 1000 LBS PER HR HIGHER THAN THE OTHER 3 ENGS. WE TRIED TO TROUBLESHOOT (CYCLING BLEEDS, MOVING THROTTLE, ETC), BUT NO IMPROVEMENT. WE DECIDED THAT AT THE INCREASED FUEL FLOW WE WOULD CUT INTO OUR FUEL RESERVES. ALSO THE ENG HEALTH WAS QUESTIONABLE, SO CAPT ELECTED TO DIVERT FOR A PRECAUTIONARY LNDG AT STANSTED, ENGLAND. KEPT #4 AT REDUCED PWR. NORMAL LNDG, NO FURTHER PROBS.

Data retrieved from NASA's ASRS site as of August 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.