Md-11 flight crew reported encountering wake turbulence that resulted in a 'rapid roll' from opposit...

Attributes
ACN	1290936
Time
Date	201508
Local Time Of Day	1201-1800
Place
Locale Reference	RJJJ.ARTCC
State Reference	FO
Aircraft 1
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Oceanic Airway A590
Flight Plan	IFR
Aircraft 2
Make Model Name	B747 Undifferentiated or Other Model
Flight Phase	Cruise
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP)
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Inflight Event / Encounter Wake Vortex Encounter

Narrative:

In cruise at FL380; 37nm northeast of tunto (on A590) we passed below an opposite direction B-747 at FL390. Shortly after passing; we encountered wake turbulence of a moderate degree. The airplane shuddered and then rapidly rolled approximately 20 degrees right. The autopilot commanded a left roll to counteract; but then kicked off. The captain assumed control and steered us away from the wake. There was no altitude deviation or loss of separation. Dispatch; maintenance control and ATC all notified of event after we returned on course. Aml entry was made as a precaution; even though no limitation exceedence of any kind was observed. [The cause was the ] 1;000 foot rvsm separation and the direct tailwind that washed the wake directly over us.

Original NASA ASRS Text

Title: MD-11 flight crew reported encountering wake turbulence that resulted in a 'rapid roll' from opposite direction B747 1;000 ft above their altitude of FL380.

Narrative: In cruise at FL380; 37nm northeast of TUNTO (on A590) we passed below an opposite direction B-747 at FL390. Shortly after passing; we encountered wake turbulence of a moderate degree. The airplane shuddered and then rapidly rolled approximately 20 degrees right. The autopilot commanded a left roll to counteract; but then kicked off. The Captain assumed control and steered us away from the wake. There was no altitude deviation or loss of separation. Dispatch; Maintenance Control and ATC all notified of event after we returned on course. AML entry was made as a precaution; even though no limitation exceedence of any kind was observed. [The cause was the ] 1;000 foot RVSM separation and the direct tailwind that washed the wake directly over us.

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.

Md-11 flight crew reported encountering wake turbulence that resulted in a 'rapid roll' from opposite direction B747 1;000 ft above their altitude of FL380.