Narrative:

Flight was en route to amsterdam from new york and had just checked in with scottish control at FL350. Clearance was given to climb to FL370. Approximately 200 ft below leveloff, the #2 autoplt tripped off. Copilot was PF and he leveled off manually at FL370 and attempted to re-engage the #2 autoplt. It tripped off again and this was followed by strong aircraft vibrations and pitch oscillations. The vibrations stopped after about 10 seconds, but were followed by two more episodes of similar strong vibrations. There was some gain and loss of altitude and scottish control was notified of this. After things settled down, the #1 autoplt was engaged and operations were normal to ams. The only system malfunctions noted were upper yaw inoperative lights illuminating. Switches were recycled and lights remained out. Cause of vibrations is unknown. No injuries of any kind were reported. Callback conversation with reporter revealed the following information: the reporter is a DC10-30 captain and he said that maintenance was unable to determine the cause of the vibrations. The maintenance personnel ran some tests, he said, and concluded their exercise by putting the #2 autoplt on the MEL. The captain said that he has checked with the maintenance department several times. They have not had further problems with the aircraft. The #2 autoplt was replaced. The altitude only varied about 200 ft up and down during the vibration episodes. He said that the crew was very concerned as none of them had ever experienced anything like this before.

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Original NASA ASRS Text

Title: AN ACR DC10 FLC HAD THE #2 AUTOPLT DISCONNECT AS THEY WERE APCHING LEVELOFF AT FL370. SHORTLY AFTER LEVELOFF, THE ACFT EXPERIENCED SEVERAL EPISODES OF VIBRATION ACCOMPANIED BY THE UPPER YAW DAMPER INOP LIGHTS ILLUMINATING. MAINT PERSONNEL COULD NOT DETERMINE THE CAUSE OF THE VIBRATIONS.

Narrative: FLT WAS ENRTE TO AMSTERDAM FROM NEW YORK AND HAD JUST CHKED IN WITH SCOTTISH CTL AT FL350. CLRNC WAS GIVEN TO CLB TO FL370. APPROX 200 FT BELOW LEVELOFF, THE #2 AUTOPLT TRIPPED OFF. COPLT WAS PF AND HE LEVELED OFF MANUALLY AT FL370 AND ATTEMPTED TO RE-ENGAGE THE #2 AUTOPLT. IT TRIPPED OFF AGAIN AND THIS WAS FOLLOWED BY STRONG ACFT VIBRATIONS AND PITCH OSCILLATIONS. THE VIBRATIONS STOPPED AFTER ABOUT 10 SECONDS, BUT WERE FOLLOWED BY TWO MORE EPISODES OF SIMILAR STRONG VIBRATIONS. THERE WAS SOME GAIN AND LOSS OF ALT AND SCOTTISH CTL WAS NOTIFIED OF THIS. AFTER THINGS SETTLED DOWN, THE #1 AUTOPLT WAS ENGAGED AND OPS WERE NORMAL TO AMS. THE ONLY SYS MALFUNCTIONS NOTED WERE UPPER YAW INOP LIGHTS ILLUMINATING. SWITCHES WERE RECYCLED AND LIGHTS REMAINED OUT. CAUSE OF VIBRATIONS IS UNKNOWN. NO INJURIES OF ANY KIND WERE RPTED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR IS A DC10-30 CAPT AND HE SAID THAT MAINT WAS UNABLE TO DETERMINE THE CAUSE OF THE VIBRATIONS. THE MAINT PERSONNEL RAN SOME TESTS, HE SAID, AND CONCLUDED THEIR EXERCISE BY PUTTING THE #2 AUTOPLT ON THE MEL. THE CAPT SAID THAT HE HAS CHKED WITH THE MAINT DEPT SEVERAL TIMES. THEY HAVE NOT HAD FURTHER PROBS WITH THE ACFT. THE #2 AUTOPLT WAS REPLACED. THE ALT ONLY VARIED ABOUT 200 FT UP AND DOWN DURING THE VIBRATION EPISODES. HE SAID THAT THE CREW WAS VERY CONCERNED AS NONE OF THEM HAD EVER EXPERIENCED ANYTHING LIKE THIS BEFORE.

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