B777-200 experiences right engine power loss. Diverts after consultation with maintenance.

Attributes
ACN	739935
Time
Date	200705
Place
Locale Reference	intersection : zzzzz
State Reference	FO
Altitude	msl single value : 34000
Aircraft 1
Controlling Facilities	artcc : zzzz.artcc
Operator	common carrier : air carrier
Make Model Name	B777-200
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 190 flight time total : 16000 flight time type : 2000
ASRS Report	739935
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : diverted to another airport
Consequence	other
Supplementary
Problem Areas	Maintenance Human Performance Aircraft Flight Crew Human Performance
Primary Problem	Aircraft

Narrative:

During level cruise; loud thump heard and aircraft experienced sharp jolt similar to clear air turbulence. First officer first noted drop in EPR on right engine. Right throttle was pulled back; and engine stabilized with normal indications. Since engine surge was suspected; un-annunciated checklist was reviewed and completed. Satcom link was established through dispatch to maintenance and data from maintenance display pages were downloaded to maintenance control. Flight attendant briefed on situation. Flight continued on route awaiting analysis by maintenance control of engine condition; then diverted. Normal engine operation throughout flight after event. Uneventful approach and overweight landing following consultation with maintenance.

Original NASA ASRS Text

Title: B777-200 EXPERIENCES RIGHT ENGINE POWER LOSS. DIVERTS AFTER CONSULTATION WITH MAINTENANCE.

Narrative: DURING LEVEL CRUISE; LOUD THUMP HEARD AND ACFT EXPERIENCED SHARP JOLT SIMILAR TO CLR AIR TURB. FO FIRST NOTED DROP IN EPR ON R ENG. R THROTTLE WAS PULLED BACK; AND ENG STABILIZED WITH NORMAL INDICATIONS. SINCE ENG SURGE WAS SUSPECTED; UN-ANNUNCIATED CHKLIST WAS REVIEWED AND COMPLETED. SATCOM LINK WAS ESTABLISHED THROUGH DISPATCH TO MAINT AND DATA FROM MAINT DISPLAY PAGES WERE DOWNLOADED TO MAINT CTL. FLT ATTENDANT BRIEFED ON SITUATION. FLT CONTINUED ON RTE AWAITING ANALYSIS BY MAINT CTL OF ENG CONDITION; THEN DIVERTED. NORMAL ENG OP THROUGHOUT FLT AFTER EVENT. UNEVENTFUL APCH AND OVERWT LNDG FOLLOWING CONSULTATION WITH MAINT.

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.