A319 flight crew reported that the aircraft had a moderate airframe vibration during climb.

Attributes
ACN	1545755
Time
Date	201805
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Total 10000
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy

Narrative:

While climbing thru 15;000 ft for FL350 we experienced a moderate airframe vibration that lasted 30-40 seconds and cycled on and off every 30-45 seconds. There was no turbulence and no jet wake associated with it. Our airspeed was 310 kts and after checking all system parameters on ECAM we concluded that there were no unusual indications. Aircraft was in clean configuration with exterior lights retracted. Vibrations were confirmed by flight attendant's. We leveled off at FL240 and slowed to 290 but the vibrations continued. I decided to return to [departure airport] and land overweight due to the lack of information available to determine the source of vibrations. Once below 15;000 the vibrations stopped below 280 kts. Landing was soft and uneventful. Airport rescue and firefighting inspected the jet and cleared us to the gate.

Original NASA ASRS Text

Title: A319 flight crew reported that the aircraft had a moderate airframe vibration during climb.

Narrative: While climbing thru 15;000 ft for FL350 we experienced a moderate airframe vibration that lasted 30-40 seconds and cycled on and off every 30-45 seconds. There was no turbulence and no jet wake associated with it. Our airspeed was 310 kts and after checking all system parameters on ECAM we concluded that there were no unusual indications. Aircraft was in clean configuration with exterior lights retracted. Vibrations were confirmed by FA's. We leveled off at FL240 and slowed to 290 but the vibrations continued. I decided to return to [departure airport] and land overweight due to the lack of information available to determine the source of vibrations. Once below 15;000 the vibrations stopped below 280 kts. Landing was soft and uneventful. Airport rescue and firefighting inspected the jet and cleared us to the gate.

Data retrieved from NASA's ASRS site 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.