Narrative:

During cruise portion of flight, level at FL250, the other pilot and I were talking. In less than 1 second, the airplane went into a 70 degree hard left bank. The autoplt kicked off and the PF recovered to level. 10 seconds or less passed then it went into a hard right bank, to probably 50 degrees bank. Our flight attendant was up serving drinks, she was knocked to the floor. I then noticed an aircraft roughly 10 mi in front of us on TCASII at our altitude. I told the controller about what had just happened. He responded as if it was no big deal! And that we were 12 mi in-trail of a B757. I requested a different altitude, but he started the B757 down. The passenger were visibly shaken but okay. The flight attendant was uninjured.

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Original NASA ASRS Text

Title: HS25 FLC ENCOUNTER WAKE TURB ROLLS WHEN IN-TRAIL AT FL250 UNDER ZDC CTL.

Narrative: DURING CRUISE PORTION OF FLT, LEVEL AT FL250, THE OTHER PLT AND I WERE TALKING. IN LESS THAN 1 SECOND, THE AIRPLANE WENT INTO A 70 DEG HARD L BANK. THE AUTOPLT KICKED OFF AND THE PF RECOVERED TO LEVEL. 10 SECONDS OR LESS PASSED THEN IT WENT INTO A HARD R BANK, TO PROBABLY 50 DEGS BANK. OUR FLT ATTENDANT WAS UP SERVING DRINKS, SHE WAS KNOCKED TO THE FLOOR. I THEN NOTICED AN ACFT ROUGHLY 10 MI IN FRONT OF US ON TCASII AT OUR ALT. I TOLD THE CTLR ABOUT WHAT HAD JUST HAPPENED. HE RESPONDED AS IF IT WAS NO BIG DEAL! AND THAT WE WERE 12 MI IN-TRAIL OF A B757. I REQUESTED A DIFFERENT ALT, BUT HE STARTED THE B757 DOWN. THE PAX WERE VISIBLY SHAKEN BUT OKAY. THE FLT ATTENDANT WAS UNINJURED.

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.