Date: 201705
Local time of day: 0601-1200
Location: LAX.Airport, CA
Light: Daylight
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
Airspace: Class E SCT
ATC / advisory: TRACON SCT
Second aircraft: Commercial Fixed Wing
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Inflight Event / Encounter Wake Vortex Encounter; Inflight Event / Encounter Loss Of Aircraft Control
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Separated Traffic; Flight Crew Took Evasive Action; Flight Crew Regained Aircraft Control; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Environment - Non Weather Related; Procedure
Primary problem: Procedure

Narrative: Descending through 14;000 ft at 280 kts (assigned) on the HLYWD1 RNAV STAR into LAX; we encountered wake turbulence from a preceding aircraft. The aircraft rolled abruptly left to between 25-30 degrees of bank; then pitched down to 6-8 degrees nose down; the PF attempted to correct the angle of bank and level the nose; then the aircraft rolled quickly and abruptly to the right to 25-30 degrees of bank again; identical in the type of rolling motion as experienced the first time. The PF instructed the PM to notify ATC of a wake turbulence encounter and to ask for a speed reduction to get more space between us and the preceding aircraft or a heading to get away from any additional encounters. The PF pressed the PA button and instructed the FAs to take their seats. The PF returned the aircraft to the assigned course and rejoined the arrival; as the aircraft had ended up 10-15 degrees off course during the encounter. ATC gave an instruction to maintain 250 kts or greater; the PF said we need to be slower to get more space between us; which the PF then requested from ATC. The controller said that we could go as slow as 230 kts; but faster is better. The PF said to ask for a heading off the arrival and to increase the distance by slowing temporarily; because we had a moderate wake turbulence encounter; which resulted in the aircraft rolling 25-30 degrees to each side. The PM requested this and the controller gave us 220 kts and said that the preceding aircraft was going to be landing on the north side and diverge from our course. The FAs were reached via interphone to ask about if they were okay and if the passengers were okay. They responded that everything was okay in the cabin. The controller inquired about any injuries; which the PM responded that everyone was alright. We were passed onto another controller who inquired about the altitude in which we had the encounter and then said we could slow to 210 to increase the spacing. The rest of the flight and landing on 25L were uneventful and the flight concluded successfully. In an event of the same nature in the future; I would exercise PIC emergency authority and turn the aircraft away from the affected area more rapidly; instead of just trying to slow to increase the spacing. Turning away would allow us to get away from any future encounters more quickly. Simply slowing the airplane could leave you in a position where if the aircraft is rolled or pitched violently; your safe speed buffer is not enough to maneuver the aircraft out of the encounter. This was the most severe wake turbulence I have experienced in my career thus far and will certainly take this as a learning experience for future encounters. I believe the FO I was flying with today (who was relatively new to the line) learned a great deal today; as well.




Synopsis: EMB-175 Captain reported encountering wake turbulence at 14;000 ft on descent into LAX that resulted in left and right rolls and a 7 degree pitch down.