Narrative:

During enroute descent from FL280 to FL200 on HYPER7; encountered wake from an A330 that was also on HYPER7 approximately 15 miles ahead of us. The seatbelt sign had just been turned on (1 minute?) for the descent/arrival and the air was smooth. The wind was on the nose at 35 knots (noted after the encounter(s)). The aircraft went through brief (2-4 seconds) of 'nibble'-like chop than 2 independent 'corkscrew'-like movements. There was no time to issue any warning to the flight attendants then the event was over. I called back to purser to inquire if anyone was hurt. No one was but he did say that folks did tumble. I told him that we had no warning. It was smooth for the remainder of the flight.we asked ATC what we were following and they replied that it was a heavy airbus. TCAS had it at 15 miles ahead. We were flying 290 knots (assigned). As I was talking with purser; I believe the 2 flying pilots were inquiring if it was a super or a heavy as we had a short discussion after I reported to captain that everyone was ok. No injuries.the severity of the encounter was certainly enough to spill coffee; carts; flight attendants and passengers. The motion was uncoordinated with pitch; yaw and roll. I doubt if we exceeded 10 degrees of roll but the yaw was opposite (roll left; yaw right) and; I think; the other way for the second set of motion. As mentioned. We did get some wake 'chop' shortly prior to the roll/yaw/pitch motions. I would categorize [the encounter] as 'moderate' in severity. It certainly could have tumbled passengers and flight attendants enough to cause injury. We got lucky.

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Original NASA ASRS Text

Title: B767 First Officer reported encountering moderate wake turbulence while on descent 15 miles in trail of an A330.

Narrative: During enroute descent from FL280 to FL200 on HYPER7; encountered wake from an A330 that was also on HYPER7 approximately 15 miles ahead of us. The seatbelt sign had just been turned on (1 minute?) for the descent/arrival and the air was smooth. The wind was on the nose at 35 knots (noted after the encounter(s)). The aircraft went through brief (2-4 seconds) of 'nibble'-like chop than 2 independent 'corkscrew'-like movements. There was no time to issue any warning to the flight attendants then the event was over. I called back to Purser to inquire if anyone was hurt. No one was but he did say that folks did tumble. I told him that we had no warning. It was smooth for the remainder of the flight.We asked ATC what we were following and they replied that it was a heavy Airbus. TCAS had it at 15 miles ahead. We were flying 290 knots (assigned). As I was talking with Purser; I believe the 2 flying pilots were inquiring if it was a Super or a Heavy as we had a short discussion after I reported to Captain that everyone was ok. No injuries.The severity of the encounter was certainly enough to spill coffee; carts; flight attendants and passengers. The motion was uncoordinated with pitch; yaw and roll. I doubt if we exceeded 10 degrees of roll but the yaw was opposite (roll left; yaw right) and; I think; the other way for the second set of motion. As mentioned. We did get some wake 'chop' shortly prior to the roll/yaw/pitch motions. I would categorize [the encounter] as 'moderate' in severity. It certainly could have tumbled passengers and flight attendants enough to cause injury. We got lucky.

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.