Narrative:

Aircraft #2 took off directly ahead of aircraft #1 on runway 34R. Winds were light. Adequate separation was not maintained. Shortly after liftoff, aircraft #1 rolled rapidly and violently left to 35 degrees wing down. The roll occurred in 1 second or less. As quickly as the wake turbulence was entered it was exited, and the pilot recovered and continued a normal flight. The passenger were alarmed.

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Original NASA ASRS Text

Title: SEA B737 DEP ENCOUNTERS WAKE OF PREVIOUS B747 DEP.

Narrative: ACFT #2 TOOK OFF DIRECTLY AHEAD OF ACFT #1 ON RWY 34R. WINDS WERE LIGHT. ADEQUATE SEPARATION WAS NOT MAINTAINED. SHORTLY AFTER LIFTOFF, ACFT #1 ROLLED RAPIDLY AND VIOLENTLY L TO 35 DEGS WING DOWN. THE ROLL OCCURRED IN 1 SECOND OR LESS. AS QUICKLY AS THE WAKE TURB WAS ENTERED IT WAS EXITED, AND THE PLT RECOVERED AND CONTINUED A NORMAL FLT. THE PAX WERE ALARMED.

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.