Narrative:

During level cruise; unaccelerated flight with autoplt connected on J107 near beryl intersection wbound; ATC called 2 traffic advisories. One was a B747 at 12 O'clock and 1000 ft above traveling eastbound. The other was another B747 1000 ft below also eastbound and about 1 mile further than the first B747. Both were identified on TCAS and we visually saw both aircraft pass us on what appeared to be same path as us but in opposite direction from us. Current winds were approximately 7 KTS from the northwest; after about a minute; our aircraft began a roll to the right and the autoplt disconnected. The roll continued to about 45 degrees of roll and then we were able to return the wings to level. The aircraft began to roll the same to the left in the same manner. The aircraft did not yaw nor did it gain or lose more than 50 ft altitude. We also didn't seem to experience any 'G' loading on the aircraft. The captain made appropriate PA's; PIREPS; and calls to the cabin and determined there were no passenger injuries but a flight attendant hit her shoulder. Due to the relatively 'gentle' nature of the event; we determined that it was a moderate turbulence event and took no further action. After discussing the matter during our next leg on the same aircraft; the captain and I researched the event further and felt that since the autoplt disconnected that would constitute a 'momentary loss of control;' which warrants a severe turbulence designation and an aircraft inspection. We then notified the company and took appropriate steps to have the aircraft inspected.

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Original NASA ASRS Text

Title: AN MD90 CREW RPTS A WAKE TURB 45 DEG BANK ROLL FOLLOWING PASSAGE OF TWO B747 ACFT 1000 FT ABOVE AND BELOW ON THE SAME TRACK.

Narrative: DURING LEVEL CRUISE; UNACCELERATED FLT WITH AUTOPLT CONNECTED ON J107 NEAR BERYL INTXN WBOUND; ATC CALLED 2 TFC ADVISORIES. ONE WAS A B747 AT 12 O'CLOCK AND 1000 FT ABOVE TRAVELING EBOUND. THE OTHER WAS ANOTHER B747 1000 FT BELOW ALSO EBOUND AND ABOUT 1 MILE FURTHER THAN THE FIRST B747. BOTH WERE IDENTIFIED ON TCAS AND WE VISUALLY SAW BOTH ACFT PASS US ON WHAT APPEARED TO BE SAME PATH AS US BUT IN OPPOSITE DIRECTION FROM US. CURRENT WINDS WERE APPROX 7 KTS FROM THE NW; AFTER ABOUT A MINUTE; OUR ACFT BEGAN A ROLL TO THE R AND THE AUTOPLT DISCONNECTED. THE ROLL CONTINUED TO ABOUT 45 DEGS OF ROLL AND THEN WE WERE ABLE TO RETURN THE WINGS TO LEVEL. THE ACFT BEGAN TO ROLL THE SAME TO THE L IN THE SAME MANNER. THE ACFT DID NOT YAW NOR DID IT GAIN OR LOSE MORE THAN 50 FT ALT. WE ALSO DIDN'T SEEM TO EXPERIENCE ANY 'G' LOADING ON THE ACFT. THE CAPT MADE APPROPRIATE PA'S; PIREPS; AND CALLS TO THE CABIN AND DETERMINED THERE WERE NO PAX INJURIES BUT A FLT ATTENDANT HIT HER SHOULDER. DUE TO THE RELATIVELY 'GENTLE' NATURE OF THE EVENT; WE DETERMINED THAT IT WAS A MODERATE TURB EVENT AND TOOK NO FURTHER ACTION. AFTER DISCUSSING THE MATTER DURING OUR NEXT LEG ON THE SAME ACFT; THE CAPT AND I RESEARCHED THE EVENT FURTHER AND FELT THAT SINCE THE AUTOPLT DISCONNECTED THAT WOULD CONSTITUTE A 'MOMENTARY LOSS OF CTL;' WHICH WARRANTS A SEVERE TURB DESIGNATION AND AN ACFT INSPECTION. WE THEN NOTIFIED THE COMPANY AND TOOK APPROPRIATE STEPS TO HAVE THE ACFT INSPECTED.

Data retrieved from NASA's ASRS site as of January 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.