B767 first officer reported wake encounter in trail of a B747 in oceanic airspace at FL320 that resu...

Attributes
ACN	1247664
Time
Date	201503
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Oceanic
Flight Plan	IFR
Aircraft 2
Make Model Name	B747 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Oceanic
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 13000 Flight Crew Type 5800
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Inflight Event / Encounter Wake Vortex Encounter

Narrative:

Initially slopped R1 on track at coast out. Hit moderate wake from aircraft at FL320 so slopped R2. The wind then shifted and we felt it better to go back to R1 to avoid the drifting contrail. Then encountered severe wake from the aircraft at FL320 13 miles in front of us. The autopilot was initially on but did not respond well with the encounter as we climbed 200 feet and rolled past 30 degrees bank. I manually took over the aircraft as the autopilot did not respond and I immediately was able to level the aircraft and roll out of the bank. As the winds were blowing the contrails into the 'slop' area we elected to fly the nat with no slop. Oceanic quickly selcaled the aircraft asking our altitude. Captain stated we were now level at FL310 and further explained the situation and that we did not fly off our altitude but were rather pushed there from the severe wake encounter. Oceanic told us it was a B747 at FL320.

Original NASA ASRS Text

Title: B767 First Officer reported wake encounter in trail of a B747 in oceanic airspace at FL320 that resulted in a 30 degree roll and a 200-foot climb.

Narrative: Initially slopped R1 on track at coast out. Hit moderate wake from aircraft at FL320 so slopped R2. The wind then shifted and we felt it better to go back to R1 to avoid the drifting contrail. Then encountered severe wake from the aircraft at FL320 13 miles in front of us. The autopilot was initially on but did not respond well with the encounter as we climbed 200 feet and rolled past 30 degrees bank. I manually took over the aircraft as the autopilot did not respond and I immediately was able to level the aircraft and roll out of the bank. As the winds were blowing the contrails into the 'slop' area we elected to fly the NAT with no slop. Oceanic quickly SELCALed the aircraft asking our altitude. Captain stated we were now level at FL310 and further explained the situation and that we did not fly off our altitude but were rather pushed there from the severe wake encounter. Oceanic told us it was a B747 at FL320.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

B767 first officer reported wake encounter in trail of a B747 in oceanic airspace at FL320 that resulted in a 30 degree roll and a 200-foot climb.