Narrative:

During descent around 20 mins from dca at approximately FL180, flight encountered extreme turbulence. The aircraft was impossible to control for approximately 5 seconds. Aircraft control was re-established and the flight continued safely to dca. Before the encounter, only light with occasional moderate turbulence was experienced. Since the flight was within 30 mins to dca, the first officer had already made the required cabin announcement to the passenger. In addition, the first officer made a call directly to the flight attendant to remain seated for her safety due to the turbulence. The flight attendant notified the pilots that several passenger had received injuries. In response, operations was called by the first officer to request medical assistance at the gate. 8 passenger were taken to the hospital, 2 removed by backboard by crash fire rescue equipment. Supplemental information from acn 566382: during the turbulence, the CL65 experienced a maximum bank angle of 45 degrees and a pitch change of 30 degrees. The seatbelt sign was on and the aircraft was written up with maintenance for extreme turbulence.

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Original NASA ASRS Text

Title: A CL65 CREW, ON DSCNT TO DCA, ENCOUNTERED EXTREME TURB AT APPROX FL180.

Narrative: DURING DSCNT AROUND 20 MINS FROM DCA AT APPROX FL180, FLT ENCOUNTERED EXTREME TURB. THE ACFT WAS IMPOSSIBLE TO CTL FOR APPROX 5 SECONDS. ACFT CTL WAS RE-ESTABLISHED AND THE FLT CONTINUED SAFELY TO DCA. BEFORE THE ENCOUNTER, ONLY LIGHT WITH OCCASIONAL MODERATE TURB WAS EXPERIENCED. SINCE THE FLT WAS WITHIN 30 MINS TO DCA, THE FO HAD ALREADY MADE THE REQUIRED CABIN ANNOUNCEMENT TO THE PAX. IN ADDITION, THE FO MADE A CALL DIRECTLY TO THE FLT ATTENDANT TO REMAIN SEATED FOR HER SAFETY DUE TO THE TURB. THE FLT ATTENDANT NOTIFIED THE PLTS THAT SEVERAL PAX HAD RECEIVED INJURIES. IN RESPONSE, OPS WAS CALLED BY THE FO TO REQUEST MEDICAL ASSISTANCE AT THE GATE. 8 PAX WERE TAKEN TO THE HOSPITAL, 2 REMOVED BY BACKBOARD BY CFR. SUPPLEMENTAL INFO FROM ACN 566382: DURING THE TURB, THE CL65 EXPERIENCED A MAX BANK ANGLE OF 45 DEGS AND A PITCH CHANGE OF 30 DEGS. THE SEATBELT SIGN WAS ON AND THE ACFT WAS WRITTEN UP WITH MAINT FOR EXTREME TURB.

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.