RPTR STATES THAT FLC OF AN ACR MD88 RPTED SEVERE TURB CAUSING THE ACFT TO ROTATE 30-40 DEGS ON ITS SIDE. RPTR SUSPECTS THE TURB WAS CAUSED BY A B757 AT THE SAME ALT MORE THAN 18 MI AHEAD OF THE MD88 AS THERE WERE NO OTHER RPTS OF TURB.

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THIS FORM WILL DESCRIBE 2 INDEPENDENT SITS INVOLVING WAKE TURB FOLLOWING A B757 AT LARGE DISTANCES. THE FIRST OCCURRENCE ON OCT/WED/97 HAPPENED WHEN A B757 AT FL350 LHY.J36.DKK WAS FOLLOWED BY AN MD88 ALSO AT FL350 18.2 NM IN TRAIL. THE MD80 RPTED SEVERE TURB AND THE PLANE WAS ROTATED 30-40 DEGS ON ITS SIDE. WITH NO OTHER RPTS OF TURB BY ANY ACFT ALL DAY; I DID NOT SUSPECT THE WX TO BE CAUSING TURB. IN FACT; I BELIEVE THE B757 VORTICES HAD DONE THIS. THE ACFT WAS 18.2 NM IN FRONT OF THE SUPER 80! WHEN I ADVISED THE PLT OF THE B757; HE ALSO SUSPECTED WAKE TURB. INCIDENT #2: ON NOV/XX/97 I WORKED TWO ARRS INTO JFK INBOUND ON J70 W OF LV; BOTH AT FL370. THE B757 LED THE B767 BY 13 NM. THE B767 RPTED MODERATE TURB AND REQUESTED ALT CHANGE. I DSNDED THE B767. I THEN QUESTIONED THE B757 AS TO HIS RIDE. THE RESPONSE WAS 'SMOOTH.' I QUESTIONED ANOTHER B767 BEHIND THE AFOREMENTIONED B767 AND HE RPTED IT AS SMOOTH AS WELL. I AM NOT TRYING TO SPECULATE AS TO WHETHER CLR AIR TURB WAS A FACTOR IN THESE INSTANCES; OR PERHAPS WX RELATED TURB. THE INCIDENT INVOLVED THE B757 AT GREAT DISTANCE (NOT THE 5 NM BUFFER WE ARE USING). I BELIEVE THIS TOPIC SHOULD BE BROUGHT TO THE ATTN OF THE AVIATION COMMUNITY TO HEIGHTEN AWARENESS AND TO HELP PRECLUDE AN ACCIDENT. I ALSO THINK THAT NASA/DOT SHOULD DO MORE INVESTIGATION INTO THIS PHENOMENON BEFORE AN ACCIDENT OCCURS.