B737-800 flight crew reported encountering wake turbulence from preceding B777 approaching dfw.

Attributes
ACN	1629445
Time
Date	201903
Local Time Of Day	1201-1800
Place
Locale Reference	ZFW.ARTCC
State Reference	TX
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Aircraft 2
Make Model Name	B777 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Total 12561
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument Flight Crew Commercial
Experience	Flight Crew Total 18000
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Inflight Event / Encounter Wake Vortex Encounter

Narrative:

While in level flight at FL250 with autopilot and autothrottles on; seat belt sign on; in the vicinity of saylr on the SEEVR4 RNAV arrival; we felt some light chop/turbulence and then the aircraft suddenly rolled left approximately 35 degrees angle of bank (we got the 'bank angle' aural warning). As pilot flying I disconnected the autopilot and rolled back to wings level and corrected back to FL250 and on course to seevr. We lost approximately 150 feet in altitude during the event; and notified ATC of the event and deviation. We asked ATC what type aircraft was in front of us; and were told that it was a '777.' flight attendants reported no passengers were up at the time of the event; no passenger or flight attendant injuries; and no complaints from the passengers. Continued on and landed uneventfully at dfw.I am not sure of how/why this event occurred. It may have been that we descended to FL250 faster than the B777 in front of us; which could have put us in their wake vortices in level flight. Possibly consider wake turbulence separation in flight by not only distance and airspeed; but also by vertical speeds/rate of descent/climb. Continue simulator training in upset/unusual attitude recovery.

Original NASA ASRS Text

Title: B737-800 flight crew reported encountering wake turbulence from preceding B777 approaching DFW.

Narrative: While in level flight at FL250 with autopilot and autothrottles ON; seat belt sign ON; in the vicinity of SAYLR on the SEEVR4 RNAV Arrival; we felt some light chop/turbulence and then the aircraft suddenly rolled left approximately 35 degrees angle of bank (we got the 'Bank Angle' aural warning). As pilot flying I disconnected the autopilot and rolled back to wings level and corrected back to FL250 and on course to SEEVR. We lost approximately 150 feet in altitude during the event; and notified ATC of the event and deviation. We asked ATC what type aircraft was in front of us; and were told that it was a '777.' Flight attendants reported no passengers were up at the time of the event; no passenger or flight attendant injuries; and no complaints from the passengers. Continued on and landed uneventfully at DFW.I am not sure of how/why this event occurred. It may have been that we descended to FL250 faster than the B777 in front of us; which could have put us in their wake vortices in level flight. Possibly consider wake turbulence separation in flight by not only distance and airspeed; but also by vertical speeds/rate of descent/climb. Continue simulator training in upset/unusual attitude recovery.

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.