Air carrier captain reported high engine vibration and an air return.

Attributes
ACN	1679720
Time
Date	201908
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Climb Takeoff
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Engine
Person 1
Function	Other / Unknown
Qualification	Flight Crew Instrument Flight Crew Commercial Flight Crew Multiengine Flight Crew Private
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

On departure from ZZZ climbing through approx 4000ft msl we experienced a strong engine vibration from engine #1. We had a blinking N1 vibration of 9.9. We followed the QRH procedure which called for disengagement of the autothrust and retarding the throttle of affected engine until the vibration level was acceptable (around 50% N1) we had approx vibration level of 4.5. We leveled off at approx 10;000 ft; [notified ATC;] and was vectored back to runway xxl and landed without incident.nothing we would have done differently.

Original NASA ASRS Text

Title: Air Carrier Captain reported high engine vibration and an air return.

Narrative: On departure from ZZZ climbing through approx 4000ft msl we experienced a strong engine vibration from engine #1. We had a blinking N1 vibration of 9.9. We followed the QRH procedure which called for disengagement of the autothrust and retarding the throttle of affected engine until the vibration level was acceptable (around 50% N1) we had approx vibration level of 4.5. We leveled off at approx 10;000 ft; [notified ATC;] and was vectored back to runway XXL and landed without incident.Nothing we would have done differently.

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.