Q400 flight crew reported encountering wake vortex following a B777 into lax that resulted in signif...

Narrative:

This is a report of a wake turbulence encounter at 10;000 ft during arrival into lax near the smo VOR. Shortly after leveling at 10;000 ft and slowing per ATC request; I encountered wake turbulence from a preceding aircraft. TCAS placed the aircraft at our 12:00 and about 10 miles. Initially; the wake encounter was very mild with only slow rolling left and right. When it persisted; I slowed my airspeed 10-15 KTS and requested a climb. Very soon the encounter worsened and I disconnected the autopilot when faced with 30 degrees of bank left and right with large control inputs required to maintain level flight. A second request for a climb was made when positive aircraft control began to deteriorate. Altitude control required a power increase to maintain altitude. I advised ATC that I was climbing to get out of a wake turbulence encounter. At about 10;300 ft; positive control resumed and I leveled off at 10;500 ft. I advised ATC that I was resuming a descent back to 10;000 ft when they provided a right vector away from my previous track. I was then advised by ATC that I was following a B777. Winds at altitude were calm. This may have had an impact on wake dissipation.

Original NASA ASRS Text

Title: Q400 flight crew reported encountering wake vortex following a B777 into LAX that resulted in significant roll. Captain deviated from assigned altitude to assure control.

Narrative: This is a report of a wake turbulence encounter at 10;000 FT during arrival into LAX near the SMO VOR. Shortly after leveling at 10;000 FT and slowing per ATC request; I encountered wake turbulence from a preceding aircraft. TCAS placed the aircraft at our 12:00 and about 10 miles. Initially; the wake encounter was very mild with only slow rolling left and right. When it persisted; I slowed my airspeed 10-15 KTS and requested a climb. Very soon the encounter worsened and I disconnected the autopilot when faced with 30 degrees of bank left and right with large control inputs required to maintain level flight. A second request for a climb was made when positive aircraft control began to deteriorate. Altitude control required a power increase to maintain altitude. I advised ATC that I was climbing to get out of a wake turbulence encounter. At about 10;300 FT; positive control resumed and I leveled off at 10;500 FT. I advised ATC that I was resuming a descent back to 10;000 FT when they provided a right vector away from my previous track. I was then advised by ATC that I was following a B777. Winds at altitude were calm. This may have had an impact on wake dissipation.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1013092
Time
Date	201205
Place
Locale Reference	LAX.Airport
State Reference	CA
Aircraft 1
Make Model Name	Q400
Operating Under FAR Part	Part 121
Flight Phase	Descent
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	Captain Check Pilot Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Pilot Not Flying First Officer
Qualification	Flight Crew Commercial
Events
Anomaly	Inflight Event / Encounter Wake Vortex Encounter

Q400 flight crew reported encountering wake vortex following a B777 into lax that resulted in significant roll. Captain deviated from assigned altitude to assure control.