Narrative:

[Operations were] uneventful until shortly after reaching cruise altitude. Meteorological conditions were clear skies and night. Noted that the right engine [oil quantity] was indicating two quarts lower since takeoff and the engine vibration indication on secondary EICAS display was slowly creeping upward toward 2.0. Pointed out my observation to the first officer (first officer) and asked him to consult the quick reference handbook (QRH). About the same time he located a procedure; the vibration indicator (right engine) turned amber. Ran the engine vibration checklist. Made two slight power reductions which seemed to stabilize the vibration for a time but each time [vibration levels] began slowly creeping toward the amber limit. At this point; I asked the first officer to contact our dispatcher. I gave the dispatcher a quick brief on our situation and noted that if I ended up retarding the thrust lever to idle with vibration remaining in the amber band; the checklist called for the engine failure/shutdown procedure. Dispatcher and I agreed a diversion to [a nearby airport] might be prudent. Made the quick coordination with air traffic control; descended normally and landed uneventfully. Engine vibration indications were normal (no amber alert) for the balance of flight. Both thrust levers were at idle for most of the descent.

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Original NASA ASRS Text

Title: B757-200 Captain reported diverting to a nearby alternate airport after experiencing high vibration levels in the right engine.

Narrative: [Operations were] uneventful until shortly after reaching cruise altitude. Meteorological conditions were clear skies and night. Noted that the right engine [oil quantity] was indicating two quarts lower since takeoff and the engine vibration indication on secondary EICAS display was slowly creeping upward toward 2.0. Pointed out my observation to the First Officer (FO) and asked him to consult the Quick Reference Handbook (QRH). About the same time he located a procedure; the vibration indicator (right engine) turned amber. Ran the ENGINE VIBRATION checklist. Made two slight power reductions which seemed to stabilize the vibration for a time but each time [vibration levels] began slowly creeping toward the amber limit. At this point; I asked the FO to contact our dispatcher. I gave the dispatcher a quick brief on our situation and noted that if I ended up retarding the thrust lever to idle with vibration remaining in the amber band; the checklist called for the ENGINE FAILURE/SHUTDOWN procedure. Dispatcher and I agreed a diversion to [a nearby airport] might be prudent. Made the quick coordination with Air Traffic Control; descended normally and landed uneventfully. Engine vibration indications were normal (no amber alert) for the balance of flight. Both thrust levers were at idle for most of the descent.

Data retrieved from NASA's ASRS site 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.