B767 Undifferentiated or Other Model
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Engineer; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Flight Crew Last 90 Days 207; Flight Crew Total 9000; Flight Crew Type 2225
Inflight Event / Encounter Wake Vortex Encounter
Air Traffic Control Issued New Clearance; Flight Crew Regained Aircraft Control
Environment - Non Weather Related
I was the pilot not flying for this flight. In cruise at FL360 with the seatbelt sign off; we started getting some occasional light chop. Shortly thereafter; around 80 miles southeast of DSM; the Captain requested that I check with ATC about getting FL380. I asked Center how the rides were at FL380 and the Controller responded that she had just handed [a B747] off at FL380 and he hadn't said a word; so she assumed it was smooth. Much earlier in the flight we had seen the B747 overhead and I noticed that it was now a little over 10 miles ahead of us on the TCAS display. I then requested FL380 and received clearance to climb to FL380.As soon as the climb was initiated; the ride smoothed out. While passing FL374 we started getting light chop again. The Captain commented that it was unfortunate we were getting the chop again now that we were getting near our altitude. Passing FL375; the aircraft began to quickly roll to the right and the control wheel displaced to the left as the autopilot tried to correct. The aircraft continued to roll to the right and passing about 25 degrees of bank; the Captain turned off the autopilot and increased the roll correction to the left. The aircraft continued to roll right beyond 35 degrees of bank before the Captain was able to stop the roll at which time we heard a loud thud in from the forward galley. The Captain was then able to return the aircraft to wings level. We were now at FL376 and the Captain asked to go back to FL360. I called Center; indicated that we believed we had gotten in someone's wake and would like to return to FL360. The Controller cleared us to return to FL360 and indicated that the [aircraft] a little over 10 miles ahead of us at FL380 was a B747. The autopilot was reengaged and we returned to FL360. The Captain then called the Purser on the interphone and she informed him that a galley cart had overturned in the forward galley and had hit a Flight Attendant in the thigh as it was falling. The Purser informed us that the affected Flight Attendant was indicating that she was OK and did not believe she was injured at that time. The purser relayed to us that the aft flight attendants had reported that they were all OK and the passengers all appeared to be OK. Also; the purser reported that some male passengers in first class had come up to the front galley and stood the galley cart back up and that nothing appeared to be damaged. The Captain then made a PA to the passengers while I flew the aircraft and monitored ATC. After his PA; he resumed the flying duties and I returned to pilot not flying duties. I reassured the passengers that everything was OK with the aircraft and updated them on our anticipated arrival time. After discussion with the Captain; since we did not encounter any load on the aircraft during the roll or severe turbulence; no logbook entry was made. The remainder of the flight was uneventful.
B767 First Officer reported encountering wake turbulence in climb at FL375 from a nearby B747 at FL380 that resulted in a 35 degree bank; causing a galley cart to overturn in the cabin.