Narrative:

Aircraft preflted twice by first officer due to the time the aircraft spent on the ground between flts. Captain also checked gear doors and general condition of aircraft. After takeoff and after gear was retracted at approximately 500 ft AGL crew noticed slight vibration. Captain checked to see if vibration was coming from one of the engines, and instructed first officer to notify tower that aircraft was returning to airport. Vibration increased to moderate level. Vibration was isolated to the nose gear area. Aircraft landed safely and turned over to maintenance.

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Original NASA ASRS Text

Title: CAPT OF ACR LTT ACFT RETURNED TO LAND SHORTLY AFTER TKOF DUE TO AN UNKNOWN EXCESSIVE ACFT VIBRATION.

Narrative: ACFT PREFLTED TWICE BY FO DUE TO THE TIME THE ACFT SPENT ON THE GND BTWN FLTS. CAPT ALSO CHKED GEAR DOORS AND GENERAL CONDITION OF ACFT. AFTER TKOF AND AFTER GEAR WAS RETRACTED AT APPROX 500 FT AGL CREW NOTICED SLIGHT VIBRATION. CAPT CHKED TO SEE IF VIBRATION WAS COMING FROM ONE OF THE ENGS, AND INSTRUCTED FO TO NOTIFY TWR THAT ACFT WAS RETURNING TO ARPT. VIBRATION INCREASED TO MODERATE LEVEL. VIBRATION WAS ISOLATED TO THE NOSE GEAR AREA. ACFT LANDED SAFELY AND TURNED OVER TO MAINT.

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.