Date: 201204
Local time of day: 1801-2400
Location: LAX.Airport, CA
Flight conditions: VMC
Light: Dusk
Aircraft: EMB ERJ 135 ER/LR
Operator: Air Taxi
Operating under: Part 135
Mission: Passenger
Flight phase: Descent
Airspace: Class E SCT
ATC / advisory: TRACON SCT
Second aircraft: B747 Undifferentiated or Other Model
Reporter organization: Air Taxi
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Anomaly: Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Wake Vortex Encounter
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Regained Aircraft Control; General Physical Injury / Incapacitation
Contributing factors: Environment - Non Weather Related; Human Factors; Procedure
Primary problem: Ambiguous

Narrative: Flight to LAX was normal with smooth flight conditions. Nearing LAX on descent (13;000 FT) we were advised by SOCAL Approach we were 10 miles in trail of a B747. Shortly after that we started encountering light 'rolling' turbulence consistent with wake turbulence. I turned on the seat belt signs and approximately 5 seconds later we encountered severe 'rolling' wake turbulence. The aircraft rolled to about 90 degrees left wing down and 30 degrees nose down. The Flight Attendant was in the aft lavatory when I turned on the seat belt sign and she immediately came into the cabin. However; she was first thrown onto the side couch then across the aisle where she hit her arm on the opposite seat. All passengers were belted and had no issues except spilled drinks. Galley contents were already secured so they stayed in place (but in big disarray) in the appropriate storage closets. Had they not been secured there would have been glass flying around the area. When we initially checked in with SOCAL we were assigned Runway 24R. I made a request for Runway 25L. The Controller acknowledged the request and advised of B747 traffic. I interpreted this to mean if we used 25L there would be heavy aircraft in the area. When we first encountered the very light wake turbulence; I remembered the B747 comment and asked ATC where the traffic was. That was when I realized the B747 was in front of us at that time and not on final (as I incorrectly assumed).The actions of the Flight Attendant of keeping the galley organized and doors closed when unused prevented a probably more serious condition. Most of the glassware was dislodged from the stored location but since she had closed the access door it was contained. Had she not done that there would have been a lot of glass flying around the cabin. During the incident I remember the excessive noise of the glasses and dishes moving around. When we opened the main galley storage door after landing just about all of the contents spilled out onto the floor. The Flight Attendant was taken to a medical facility after landing because of an injury to her arm. She is fine; although a little bit sore.




Synopsis: An EMB-135-BJ encountered significant wake turbulence behind a B747 on arrival into LAX that resulted in a 90 degree roll and 30 degree nose down pitch. Flight Attendant reported slight injuries.