Narrative:

During the climbout; we experience a severe airframe vibration. We declared an in-flight emergency and return to departure airport for an uneventful landing.

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Original NASA ASRS Text

Title: A319 flight crew reports a loud vibrating; pounding noise passing FL230. When ATC communications become nearly impossible the crew elects to declare an emergency and return to the departure airport. At FL200 in the descent the noise disappears and a normal landing ensues.

Narrative: During the climbout; we experience a severe airframe vibration. We declared an in-flight emergency and return to departure airport for an uneventful landing.

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.