Narrative:

In cruise, at FL350, we experienced strong, moderate (almost severe) turbulence. We asked for and received an immediate descent to FL330. As we passed FL340 we asked for 280 since we were still in strong moderate turbulence. Center cleared us to FL330 only for traffic. We again asked for lower with a heading change if necessary. ATC then cleared us for a 70 degree right-hand turn (which we interpreted as also clearance for lower. As we passed FL330 center restated only cleared to FL330. Actual excursion was to 32700 and it occurred during the still strong, moderate turbulence, in a turn. An immediate climb to FL330 was initiated along with another request for further descent. Finally center cleared us to FL280, where the ride improved. We reported turbulence to ATC and also relayed to company dispatch. We were subsequently asked to contact seattle ATC, by telephone after landing. No emergency authority was utilized. No aircraft damage nor passenger injuries were sustained. We contacted seattle ATC. He said that after a review of the tape, and that under the circumstances, he determined that there was no incident -- case closed!

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Original NASA ASRS Text

Title: FLT CREW OF ACR LGT IN CRUISE OVER MT SHASTA ENROUTE TO BTG VORTAC EXPERIENCES EXCESSIVE TURBULENCE AT FL350. WHEN THEY ASK FOR FL280, THEIR REQUEST WAS DENIED, BUT THEY INADVERTENTLY DESCENDED THROUGH THEIR ASSIGNED ALT ANYWAY.

Narrative: IN CRUISE, AT FL350, WE EXPERIENCED STRONG, MODERATE (ALMOST SEVERE) TURB. WE ASKED FOR AND RECEIVED AN IMMEDIATE DSCNT TO FL330. AS WE PASSED FL340 WE ASKED FOR 280 SINCE WE WERE STILL IN STRONG MODERATE TURBULENCE. CENTER CLRED US TO FL330 ONLY FOR TFC. WE AGAIN ASKED FOR LOWER WITH A HDG CHANGE IF NECESSARY. ATC THEN CLRED US FOR A 70 DEG RIGHT-HAND TURN (WHICH WE INTERPRETED AS ALSO CLRNC FOR LOWER. AS WE PASSED FL330 CENTER RESTATED ONLY CLRED TO FL330. ACTUAL EXCURSION WAS TO 32700 AND IT OCCURRED DURING THE STILL STRONG, MODERATE TURB, IN A TURN. AN IMMEDIATE CLIMB TO FL330 WAS INITIATED ALONG WITH ANOTHER REQUEST FOR FURTHER DSCNT. FINALLY CENTER CLRED US TO FL280, WHERE THE RIDE IMPROVED. WE REPORTED TURBULENCE TO ATC AND ALSO RELAYED TO COMPANY DISPATCH. WE WERE SUBSEQUENTLY ASKED TO CONTACT SEATTLE ATC, BY TELEPHONE AFTER LNDG. NO EMER AUTHORITY WAS UTILIZED. NO ACFT DAMAGE NOR PAX INJURIES WERE SUSTAINED. WE CONTACTED SEATTLE ATC. HE SAID THAT AFTER A REVIEW OF THE TAPE, AND THAT UNDER THE CIRCUMSTANCES, HE DETERMINED THAT THERE WAS NO INCIDENT -- CASE CLOSED!

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.