Narrative:

This form will describe 2 independent sits involving wake turbulence 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 reported severe turbulence and the plane was rotated 30-40 degrees on its side. With no other reports of turbulence by any aircraft all day, I did not suspect the WX to be causing turbulence. In fact, I believe the B757 vortices had done this. The aircraft was 18.2 NM in front of the super 80! When I advised the pilot of the B757, he also suspected wake turbulence. Incident #2: on nov/xx/97 I worked two arrs into jfk inbound on J70 west of lv, both at FL370. The B757 led the B767 by 13 NM. The B767 reported moderate turbulence and requested altitude change. I descended 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 reported it as smooth as well. I am not trying to speculate as to whether clear air turbulence was a factor in these instances, or perhaps WX related turbulence. 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 attention 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.

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Original NASA ASRS Text

Title: 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.

Narrative: 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.

Data retrieved from NASA's ASRS site as of July 2007 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.