B787 flight crew reported a Flight Attendant suffered a minor injury during a wake turbulence encounter at FL380 in cruise flight over the Atlantic.
Synopsis
B787 flight crew reported a Flight Attendant suffered a minor injury during a wake turbulence encounter at FL380 in cruise flight over the Atlantic.
Narrative
While flying at night in smooth air at FL380; a moderate bump/jolt was felt for about 3 seconds. It was over before we could even think about making an announcement for the Flight Attendants (FAs) to be seated. We immediately suspected wake turbulence due to awareness of crossing traffic above our altitude slightly prior to the event and past experience with wake encounters. After the event was obviously over; the Pilot Monitoring (PM) made a PA for the FAs to check-in to make sure everyone was OK; as this was a significant jolt and completely unexpected. The purser first reported everything appeared fine; then said she would walk the aisle to check for any passenger or FA concerns. After returning; she again reported everything was OK throughout the airplane. About 10 minutes later; she mentioned to the PM that her own hand was bruised slightly and she was going to apply some ice. She mentioned later that she thinks she banged it on a sharp edge of one of the galley cart latch bars during the event.
Second reporter narrative
I was on break in the crew rest bunk and felt a momentary turbulence of moderate intensity. First Officers (FO) reported the following: FL380 Moncton Center. Crossing airplane 1;000 feet above. Near waypoint QUBIS on the flight plan. First reports were no injuries/issues; then same Flight Attendant (FA) reported her finger hurt and she was going to put ice on it.ATC advisory for crossing aircraft several minutes prior to event; visual on aircraft crossing well ahead of us. Smooth air; sudden moderate bump lasting approximately 3 seconds; then immediately smooth again. No deviations of bank; pitch; or speed. Seat belt sign was immediately turned on and several seconds after event a call was made for FA to check in.
NASA callback
Reporter stated the flight crew was surprised they had an encounter; it did not seem to be a scenario where wake turbulence was likely to be an issue.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.