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MD11 flight crew experiences 'engine 2 vib hi' during engine start. It is decided that ice may be the cause; but no action is required other than a runup. Before a runup can be accomplished the vibration ceases and the flight departs. Maintenance discovers compressor blade damage during post flight inspection.
| Attributes | |
| ACN | 1130114 |
| Time | |
| Date | 201311 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | MD-11 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Parked |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | Compressor Blade |
| Person 1 | |
| Function | Captain Pilot Not Flying |
| Experience | Flight Crew Last 90 Days 120 Flight Crew Total 10000 Flight Crew Type 5000 |
| Person 2 | |
| Function | Pilot Flying First Officer |
| Experience | Flight Crew Last 90 Days 136 Flight Crew Total 8100 Flight Crew Type 1996 |
| Events | |
| Anomaly | Aircraft Equipment Problem Less Severe Ground Event / Encounter Other / Unknown |
Narrative:
After type 1 deice of wings; tail and fuselage as we requested; started all three engines; placed anti-ice on due to taxiway contamination. Soon after the number 2 engine was stable we noted level one engine 2 hi vibration alert on evm compressor indicating as high as 5.0 for 3 minutes. Completed level one checklist; maintenance; consequences none; with all other engine indications normal and enter level of vibration and duration in logbook. After completing checklist; we discussed a couple of options with the mechanic on the headset. The mechanic had mentioned there was ice fog the night before our departure that the aircraft had been exposed to all night. We would either shut down all three engines and deice the number 2 engine or perform a momentary 50% N1 ice clearing to shed any ice from the compressor blades. While discussing this; the evm compressor vibration dropped to 0.4 and all other engine indications matched number 1 and 3 engines; so we entered the write-up in the logbook and taxied out. We performed a precautionary 50% N1 momentary engine clearing on the taxi out on the number 2 engine and I closely monitored all engine indications on takeoff roll and everything was normal. After arrival; the mechanic called me and said 7 compressor blades were damaged and they had to borescope the engine.
Original NASA ASRS Text
Title: MD11 flight crew experiences 'ENGINE 2 VIB HI' during engine start. It is decided that ice may be the cause; but no action is required other than a runup. Before a runup can be accomplished the vibration ceases and the flight departs. Maintenance discovers compressor blade damage during post flight inspection.
Narrative: After Type 1 deice of wings; tail and fuselage as we requested; started all three engines; placed anti-ice on due to taxiway contamination. Soon after the Number 2 Engine was stable we noted level one ENGINE 2 HI VIBRATION alert on EVM compressor indicating as high as 5.0 for 3 minutes. Completed Level One Checklist; MAINT; consequences none; with all other engine indications normal and enter level of vibration and duration in logbook. After completing checklist; we discussed a couple of options with the Mechanic on the headset. The Mechanic had mentioned there was ice fog the night before our departure that the aircraft had been exposed to all night. We would either shut down all three engines and deice the Number 2 Engine or perform a momentary 50% N1 ice clearing to shed any ice from the compressor blades. While discussing this; the EVM compressor vibration dropped to 0.4 and all other engine indications matched Number 1 and 3 engines; so we entered the write-up in the logbook and taxied out. We performed a precautionary 50% N1 momentary engine clearing on the taxi out on the Number 2 Engine and I closely monitored all engine indications on takeoff roll and everything was normal. After arrival; the mechanic called me and said 7 compressor blades were damaged and they had to borescope the engine.
Data retrieved from NASA's ASRS site as of July 2013 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.