A320 flight crew experienced high N1 vibration at FL350. Altering thrust and altitude along with eng...

Attributes
ACN	944969
Time
Date	201104
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Flight Conditions	IMC
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Component
Aircraft Component	Fan
Person 1
Function	First Officer Pilot Flying
Experience	Flight Crew Last 90 Days 180 Flight Crew Total 10500 Flight Crew Type 5600
Person 2
Function	Pilot Not Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 250 Flight Crew Total 23000 Flight Crew Type 450
Events
Anomaly	Aircraft Equipment Problem Less Severe Inflight Event / Encounter Weather / Turbulence

Narrative:

Enroute at FL350; experienced noticeable aircraft vibration with associated flashing N1 indicator; reading of 6.1; on engine #2. Other parameters [were] normal. [We] referred to flight manual; high engine vibration irregular. Requested lower altitude and turned on engine anti-ice thinking ice build up may have caused condition. Able to stabilize indication/vibration less than 5.0 at FL310; .75 mach. Captain communicated with dispatch; maintenance; flight attendants. [We] decided to declare emergency with center intending to proceed direct to destination. Vibration indication appeared normal by approach phase below 10;000 ft. Normal approach; landing and rollout.

Original NASA ASRS Text

Title: A320 flight crew experienced high N1 vibration at FL350. Altering thrust and altitude along with engine anti-ice have little effect. An emergency was declared during descent but the vibration completely disappeared below 10;000 FT.

Narrative: Enroute at FL350; experienced noticeable aircraft vibration with associated flashing N1 indicator; reading of 6.1; on engine #2. Other parameters [were] normal. [We] referred to Flight Manual; High Engine Vibration irregular. Requested lower altitude and turned on engine anti-ice thinking ice build up may have caused condition. Able to stabilize indication/vibration less than 5.0 at FL310; .75 MACH. Captain communicated with Dispatch; Maintenance; flight attendants. [We] decided to declare emergency with Center intending to proceed direct to destination. Vibration indication appeared normal by approach phase below 10;000 FT. Normal approach; landing and rollout.

Data retrieved from NASA's ASRS site as of April 2012 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.

A320 flight crew experienced high N1 vibration at FL350. Altering thrust and altitude along with engine anti-ice have little effect. An emergency was declared during descent but the vibration completely disappeared below 10;000 ft.