B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 224
Inflight Event / Encounter Wake Vortex Encounter
General None Reported / Taken
Environment - Non Weather Related; Procedure
Received a five-second burst of heavy; moderate turbulence. Contacted ATC and was told we had crossed the path of an Airbus 380 20 miles [ahead.] We had winds of 297 at 46 knots. No damage or injuries just the strongest jolt of wake I personally have ever received.
Cruising at FL390; the ride had been perfectly smooth the entire flight; no weather in the area; basically clear skies and great visibility; seatbelt sign was off (auto). Out of nowhere; the aircraft began to roll left wing down and then snapped right wing down and what felt like 'heavy' moderate turbulence lasting about three to four seconds. The autopilot and all FMA modes remained engaged. I would NOT say the aircraft was out of control per the definition of severe turbulence. The Captain checked with the flight attendants to ensure everyone was okay and made a PA explaining to the passengers that everything was okay. Meanwhile; noticing that we had a left-quartering tailwind (247/46); I asked ATC if we were following another aircraft (nothing seen on our TCAS.) ATC replied we were not. I reported our encounter with clear air turbulence and he looked further into the matter. After his investigation; we were informed that indeed an Airbus A380 had crossed over ahead of us at FL400 prior to our encounter. I informed him that in this situation; with a quartering tailwind; it's most likely we would encounter the wake of a larger aircraft. ATC took down the information of the encounter and advised us he would document the event and look into changing their vertical separation and be more aware of a tailwind condition for the smaller following traffic. Immediately after the wake turbulence; we resumed a smooth ride for the duration of cruise flight. No injuries or aircraft damage occurred during this event.
B737-700 flight crew reported wake vortex encounter at FL390 when an Airbus A380 crossed their path at FL400. The wake encounter resulted in a sharp roll to the left and then right.