Narrative:

Experienced severe engine vibration. Returned to fullerton. Landed downwind on north side taxiway. Aircraft would not develop sufficient power to maintain altitude. I declared emergency but it was not acknowledged.

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Original NASA ASRS Text

Title: PLT OF AN SMA SEL RETURNED AND LANDED DOWNWIND ON A TXWY AFTER EXPERIENCING A SEVERE ENG VIBRATION AND LOSS OF PWR.

Narrative: EXPERIENCED SEVERE ENG VIBRATION. RETURNED TO FULLERTON. LANDED DOWNWIND ON N SIDE TXWY. ACFT WOULD NOT DEVELOP SUFFICIENT PWR TO MAINTAIN ALT. I DECLARED EMER BUT IT WAS NOT ACKNOWLEDGED.

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.