During a routine arrival wake turbulence was encountered causing a startling rapid roll.

Attributes
ACN	789248
Time
Date	200806
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : atl.airport
State Reference	GA
Altitude	msl single value : 12000
Environment
Flight Conditions	VMC
Light	Dusk
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	EMB ERJ 170/175 ER&LR
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	arrival star : erlin
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 120 flight time total : 1930 flight time type : 600
ASRS Report	789248
Events
Anomaly	inflight encounter : wake turbulence
Independent Detector	other flight crewa
Resolutory Action	none taken : unable
Supplementary
Problem Areas	Environmental Factor
Primary Problem	Environmental Factor

Narrative:

We were on the erlin 3 arrival into atl. All dscnts and speed reductions had been normal for atl (we were slowed a little early). Upon passing; around stutz intersection on the arrival; around 12000 ft MSL the aircraft encountered wake turbulence of the preceding aircraft (we think); which later was believed to be a B737 (or another passing aircraft). Our aircraft was flying on the autoplt at the time of the encounter. The airplane rolled rapidly approximately 30 degrees in either direction. The autoplt tended to overcorrect so I used the tcs button to override the automation. We never received any warnings from ATC of wake turbulence. After the encounter the captain called the flight attendants to make sure everyone was okay. No one was hurt; just startled. He made the appropriate announcements to the passenger explaining the situation. Obviously; we can't detect wake turbulence; so we couldn't have done much more. That was my first encounter with wake turbulence that bad.

Original NASA ASRS Text

Title: DURING A ROUTINE ARR WAKE TURBULENCE WAS ENCOUNTERED CAUSING A STARTLING RAPID ROLL.

Narrative: WE WERE ON THE ERLIN 3 ARR INTO ATL. ALL DSCNTS AND SPEED REDUCTIONS HAD BEEN NORMAL FOR ATL (WE WERE SLOWED A LITTLE EARLY). UPON PASSING; AROUND STUTZ INTXN ON THE ARR; AROUND 12000 FT MSL THE ACFT ENCOUNTERED WAKE TURBULENCE OF THE PRECEDING ACFT (WE THINK); WHICH LATER WAS BELIEVED TO BE A B737 (OR ANOTHER PASSING ACFT). OUR ACFT WAS FLYING ON THE AUTOPLT AT THE TIME OF THE ENCOUNTER. THE AIRPLANE ROLLED RAPIDLY APPROX 30 DEGS IN EITHER DIRECTION. THE AUTOPLT TENDED TO OVERCORRECT SO I USED THE TCS BUTTON TO OVERRIDE THE AUTOMATION. WE NEVER RECEIVED ANY WARNINGS FROM ATC OF WAKE TURBULENCE. AFTER THE ENCOUNTER THE CAPT CALLED THE FLT ATTENDANTS TO MAKE SURE EVERYONE WAS OKAY. NO ONE WAS HURT; JUST STARTLED. HE MADE THE APPROPRIATE ANNOUNCEMENTS TO THE PAX EXPLAINING THE SITUATION. OBVIOUSLY; WE CAN'T DETECT WAKE TURBULENCE; SO WE COULDN'T HAVE DONE MUCH MORE. THAT WAS MY FIRST ENCOUNTER WITH WAKE TURBULENCE THAT BAD.

Data retrieved from NASA's ASRS site as of May 2009 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.