Narrative:

We were level at cruise FL320 approximately 40 minutes after blocking out from ZZZ. WX was not a factor. We suddenly experienced an abrupt roll to the right to approximately 45 degrees and then an abrupt turn to the left; autopilot disengaged and we again rolled back to the right where I was then able to control the aircraft. I did not take specific note of the exact altitude loss since I was more concerned with getting the aircraft upright but it was not significant; approximately 200-300 ft. I reported it to center and was told they descended a B777 9 miles in front of us. Winds were 230/50 (45 KT direct headwind). We were eventually switched to the next sector (still center) and descended to FL280 (not sure exact altitude) when about 15-20 minutes after the first encounter we again experienced the second episode of wake turbulence. This time I took control of the aircraft and proceeded on an offset to the right of course. I informed center and was cleared for a 5 mile offset. The winds this time were 31 KTS direct headwind. I spoke with the center chief. I did receive a call from the center safety office and spoke with him at great length about the incident. They informed me they also had another incident with a giv and B747 within a few days of our encounter. I suspect many of these encounters are not being reported. We were fortunate no one was injured on our aircraft; but under different circumstances they could have been.

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Original NASA ASRS Text

Title: A G4 AT FL320 FOLLOWING A B777 BY NINE MILES EXPERIENCED WAKE VORTEX UPSET WITH A 45 DEG ROLL AND 200-300 FT ALT LOSS.

Narrative: WE WERE LEVEL AT CRUISE FL320 APPROX 40 MINUTES AFTER BLOCKING OUT FROM ZZZ. WX WAS NOT A FACTOR. WE SUDDENLY EXPERIENCED AN ABRUPT ROLL TO THE R TO APPROX 45 DEGS AND THEN AN ABRUPT TURN TO THE L; AUTOPILOT DISENGAGED AND WE AGAIN ROLLED BACK TO THE R WHERE I WAS THEN ABLE TO CTL THE ACFT. I DID NOT TAKE SPECIFIC NOTE OF THE EXACT ALTITUDE LOSS SINCE I WAS MORE CONCERNED WITH GETTING THE ACFT UPRIGHT BUT IT WAS NOT SIGNIFICANT; APPROX 200-300 FT. I RPTED IT TO CENTER AND WAS TOLD THEY DSNDED A B777 9 MILES IN FRONT OF US. WINDS WERE 230/50 (45 KT DIRECT HEADWIND). WE WERE EVENTUALLY SWITCHED TO THE NEXT SECTOR (STILL CENTER) AND DSNDED TO FL280 (NOT SURE EXACT ALTITUDE) WHEN ABOUT 15-20 MINUTES AFTER THE FIRST ENCOUNTER WE AGAIN EXPERIENCED THE SECOND EPISODE OF WAKE TURBULENCE. THIS TIME I TOOK CTL OF THE ACFT AND PROCEEDED ON AN OFFSET TO THE R OF COURSE. I INFORMED CENTER AND WAS CLEARED FOR A 5 MILE OFFSET. THE WINDS THIS TIME WERE 31 KTS DIRECT HEADWIND. I SPOKE WITH THE CENTER CHIEF. I DID RECEIVE A CALL FROM THE CENTER SAFETY OFFICE AND SPOKE WITH HIM AT GREAT LENGTH ABOUT THE INCIDENT. THEY INFORMED ME THEY ALSO HAD ANOTHER INCIDENT WITH A GIV AND B747 WITHIN A FEW DAYS OF OUR ENCOUNTER. I SUSPECT MANY OF THESE ENCOUNTERS ARE NOT BEING RPTED. WE WERE FORTUNATE NO ONE WAS INJURED ON OUR ACFT; BUT UNDER DIFFERENT CIRCUMSTANCES THEY COULD HAVE BEEN.

Data retrieved from NASA's ASRS site as of May 2009 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.