Narrative:

At FL350, engine anti-ice on, right engine system fail alert, all other engine indications normal. WX conditions were IMC, vectoring (radar vectors) for WX around cqo area, icing conditions, but no indications on aircraft (accumulation). Airspeed began to slightly decrease. Airframe and tail anti-ice were turned on but there was still no accumulation. Asked ATC for lower. ATC wanted us to stay where we were due to crossing traffic (about 5 mi). FMA thrust indication went to mct and airspeed slightly decreased again. Again requested lower altitude from ATC. ATC again denied but gave us a turn instead. Began a 5 degree turn to the right, encountered a wave-type turbulence (like going lengthwise over a wave). As a result of wave turbulence, stick shaker for about 1/2 second, occurred with a descent starting down. Captain paddled autoplt to stop descent. Told ATC that we needed lower, then got a TA from other aircraft but was not in a dangerous position to aircraft (note: ATC gave the lower aircraft a right turn but they refused turn.) descent was stopped approximately 1200 ft below our flight level. Lower aircraft passed 2 NM behind us. ATC gave us lower. Aircraft responded normally at lower altitude. The rest of flight was uneventful and aircraft responded normally. During the above situation the flight attendant called numerous (3-4) times about a vibration in business and aft cabin. Jumpseaters (pilots) in business class indicated the vibration and noise was not normal. While in the cockpit neither I nor the captain heard nor felt a vibration throughout the situation.

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Original NASA ASRS Text

Title: A B717-200 FO RPTED THAT ZID REFUSED THEIR REQUEST FOR A LOWER ALT AFTER THEY ENCOUNTERED ICING WHICH CAUSED SIGNIFICANT PROBS FOR THE FLT.

Narrative: AT FL350, ENG ANTI-ICE ON, R ENG SYS FAIL ALERT, ALL OTHER ENG INDICATIONS NORMAL. WX CONDITIONS WERE IMC, VECTORING (RADAR VECTORS) FOR WX AROUND CQO AREA, ICING CONDITIONS, BUT NO INDICATIONS ON ACFT (ACCUMULATION). AIRSPD BEGAN TO SLIGHTLY DECREASE. AIRFRAME AND TAIL ANTI-ICE WERE TURNED ON BUT THERE WAS STILL NO ACCUMULATION. ASKED ATC FOR LOWER. ATC WANTED US TO STAY WHERE WE WERE DUE TO XING TFC (ABOUT 5 MI). FMA THRUST INDICATION WENT TO MCT AND AIRSPEED SLIGHTLY DECREASED AGAIN. AGAIN REQUESTED LOWER ALT FROM ATC. ATC AGAIN DENIED BUT GAVE US A TURN INSTEAD. BEGAN A 5 DEG TURN TO THE R, ENCOUNTERED A WAVE-TYPE TURB (LIKE GOING LENGTHWISE OVER A WAVE). AS A RESULT OF WAVE TURB, STICK SHAKER FOR ABOUT 1/2 SECOND, OCCURRED WITH A DSCNT STARTING DOWN. CAPT PADDLED AUTOPLT TO STOP DSCNT. TOLD ATC THAT WE NEEDED LOWER, THEN GOT A TA FROM OTHER ACFT BUT WAS NOT IN A DANGEROUS POS TO ACFT (NOTE: ATC GAVE THE LOWER ACFT A R TURN BUT THEY REFUSED TURN.) DSCNT WAS STOPPED APPROX 1200 FT BELOW OUR FLT LEVEL. LOWER ACFT PASSED 2 NM BEHIND US. ATC GAVE US LOWER. ACFT RESPONDED NORMALLY AT LOWER ALT. THE REST OF FLT WAS UNEVENTFUL AND ACFT RESPONDED NORMALLY. DURING THE ABOVE SIT THE FLT ATTENDANT CALLED NUMEROUS (3-4) TIMES ABOUT A VIBRATION IN BUSINESS AND AFT CABIN. JUMPSEATERS (PLTS) IN BUSINESS CLASS INDICATED THE VIBRATION AND NOISE WAS NOT NORMAL. WHILE IN THE COCKPIT NEITHER I NOR THE CAPT HEARD NOR FELT A VIBRATION THROUGHOUT THE SIT.

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.