An hs-125 first officer reported encountering wake turbulence at 15;000 ft inbound to iad.

Attributes
ACN	978480
Time
Date	201111
Local Time Of Day	1201-1800
Place
Locale Reference	IAD.Airport
State Reference	DC
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	HS 125 Series
Operating Under FAR Part	Part 91
Flight Phase	Descent
Route In Use	STAR HYPER 3
Flight Plan	IFR
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 125 Flight Crew Total 5900 Flight Crew Type 4900
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Inflight Event / Encounter Wake Vortex Encounter

Narrative:

Level at 15;000 ft; we encountered severe turbulence. [We] deviated from altitude while recovering from aircraft upset due to what appeared to be wake turbulence. [We] alerted ATC of our deviation [and] resumed arrival to iad at a reduced airspeed. Remainder of flight was normal.

Original NASA ASRS Text

Title: An HS-125 First Officer reported encountering wake turbulence at 15;000 FT inbound to IAD.

Narrative: Level at 15;000 FT; we encountered severe turbulence. [We] deviated from altitude while recovering from aircraft upset due to what appeared to be wake turbulence. [We] alerted ATC of our deviation [and] resumed arrival to IAD at a reduced airspeed. Remainder of flight was normal.

Data retrieved from NASA's ASRS site as of April 2012 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.