Phenom 300 flight crew reported unusual vibrations during cruise from an undetermined source.

Attributes
ACN	1501099
Time
Date	201712
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	EMB-505 / Phenom 300
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Vectors
Flight Plan	IFR
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 60 Flight Crew Total 7500 Flight Crew Type 500
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

While executing a routine aircraft verification flight at FL450 felt an unusual vibration and could not determine whether it originated from one of the engines; or whether it was a control surface issue. Immediately requested to leave FL450 and return to land.controllers were very proactive giving us direct clearances and allowing us to land in a short amount of time.

Original NASA ASRS Text

Title: Phenom 300 flight crew reported unusual vibrations during cruise from an undetermined source.

Narrative: While executing a routine aircraft verification flight at FL450 felt an unusual vibration and could not determine whether it originated from one of the engines; or whether it was a control surface issue. Immediately requested to leave FL450 and return to land.Controllers were very proactive giving us direct clearances and allowing us to land in a short amount of time.

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.