B757 captain reported two wake vortex encounters in trail of a B777 departing lax.

Attributes
ACN	1337472
Time
Date	201603
Local Time Of Day	1201-1800
Place
Locale Reference	ZLA.ARTCC
State Reference	CA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Climb
Route In Use	SID LOOP 8
Flight Plan	IFR
Aircraft 2
Make Model Name	B777 Undifferentiated or Other Model
Operating Under FAR Part	Part 129
Flight Phase	Climb
Route In Use	SID LOOP 8
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 160 Flight Crew Type 9821
Events
Anomaly	Deviation - Procedural Clearance Deviation - Track / Heading All Types Inflight Event / Encounter Wake Vortex Encounter

Narrative:

Two wake turbulence [encounters]. One on initial climb following a [heavy] B777 on takeoff. Upon ascertaining we would be following a 777 in T/O sequence; I stated to the first officer prior to taking the runway that I will only go ahead with ample separation. At throttle up we had approximately 12 miles behind the 777 ahead. On initial climb; after the turn to 236 degrees at approx. 5000-8000 we had several clear ripples of wake turbulence. Estimating the climb gradient of the preceding traffic we maximized the climb and adjusted the path (widening turn back to lax VOR). Upon passing lax VOR turning eastbound; as we climbed through approximately 20;000 feet; the preceding aircraft was approx. 2000 above our altitude and established 24-26 miles ahead of us. I stated again to the first officer the possibility of wake; and at that second experienced substantial wake turbulence. Not a rolling moment (yet) but a very strong buffeting and noticeable wake experience. We advised ATC we will be turning to offset from our current track due to the wake. For expediency I clicked off the autopilot and turned approximately 30 degrees to the right with ATC almost simultaneously agreeing and advising for the turn. I was more proactive than ATC. No conflict was stated by ATC; however his response to us was very drawn out; lengthy; and slow. We needed to change track behind the heavy ahead as soon as possible. Our action prevented any further disturbance. Sct was the controlling agency; between lax and dag VOR.

Original NASA ASRS Text

Title: B757 Captain reported two wake vortex encounters in trail of a B777 departing LAX.

Narrative: Two wake turbulence [encounters]. One on initial climb following a [heavy] B777 on takeoff. Upon ascertaining we would be following a 777 in T/O sequence; I stated to the FO prior to taking the runway that I will only go ahead with ample separation. At throttle up we had approximately 12 miles behind the 777 ahead. On initial climb; after the turn to 236 degrees at approx. 5000-8000 we had several clear ripples of wake turbulence. Estimating the climb gradient of the preceding traffic we maximized the climb and adjusted the path (widening turn back to LAX VOR). Upon passing LAX VOR turning eastbound; as we climbed through approximately 20;000 feet; the preceding aircraft was approx. 2000 above our altitude and established 24-26 miles ahead of us. I stated again to the FO the possibility of wake; and at that second experienced SUBSTANTIAL wake turbulence. Not a rolling moment (yet) but a very strong buffeting and noticeable wake experience. We advised ATC we will be turning to offset from our current track due to the wake. For expediency I clicked off the autopilot and turned approximately 30 degrees to the right with ATC almost simultaneously agreeing and advising for the turn. I was more proactive than ATC. No conflict was stated by ATC; however his response to us was very drawn out; lengthy; and slow. We needed to change track behind the heavy ahead ASAP. Our action prevented any further disturbance. SCT was the controlling agency; between LAX and DAG VOR.

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.