Narrative:

Going into the thirteenth hour of duty. Started out normal from O'hare airport. We climbed to 16000' and leveled off. We had light to moderate chop along the entire route. We were going to get radar vectors for the ILS runway 8 at cwa but ended up doing the approach going direct to auw VOR then the 237 degree right to do the procedure turn. 1/2 way through the procedure with no stall warning, the aircraft started a buffet that got progressively worse, and then the bottom dropped out. The aircraft rolled sharply in one direction, then in the opp direction about 90 degrees. All the while the captain was asking if there was ice on the airframe and I was looking and just saw the airframe appear wet and responding that way. We had level 2 anti-icing on before this condition started and during it we put level 3 on. We increased power to maximum and this seemed to help control the rolling tendencies, but the aircraft was still not responding fully. I said 'propellers' and the captain said 'maximum.' I pushed them up to maximum RPM and the aircraft started to be ctlable again. Until the propellers were pushed to maximum RPM, I truly believed that we were going to impact the terrain. I did forget to say that the GPWS was saying 'terrain, terrain...' after getting the aircraft flying again we climbed to 6000' and got radar vectors for a 15 mi final on the ILS 8 and landed safely. I think we got massive clear icing in the procedure turn and stalled! This aircraft has black spinners and it's great to see rime icing, but not clear. Also the speed for clean confign in icing conditions with accretion is vref + 60. I think to keep this airplane safe to fly we need some indicator to let us know we have ice on the airframe we cannot see. We also need an indication aurally that the speed has gone below 160 KIAS.

Related reports:

Google
 

Original NASA ASRS Text

Title: FLT CREW STALLED ACR MDT IN ICING CONDITIONS.

Narrative: GOING INTO THE THIRTEENTH HR OF DUTY. STARTED OUT NORMAL FROM O'HARE ARPT. WE CLBED TO 16000' AND LEVELED OFF. WE HAD LIGHT TO MODERATE CHOP ALONG THE ENTIRE ROUTE. WE WERE GOING TO GET RADAR VECTORS FOR THE ILS RWY 8 AT CWA BUT ENDED UP DOING THE APCH GOING DIRECT TO AUW VOR THEN THE 237 DEG R TO DO THE PROC TURN. 1/2 WAY THROUGH THE PROC WITH NO STALL WARNING, THE ACFT STARTED A BUFFET THAT GOT PROGRESSIVELY WORSE, AND THEN THE BOTTOM DROPPED OUT. THE ACFT ROLLED SHARPLY IN ONE DIRECTION, THEN IN THE OPP DIRECTION ABOUT 90 DEGS. ALL THE WHILE THE CAPT WAS ASKING IF THERE WAS ICE ON THE AIRFRAME AND I WAS LOOKING AND JUST SAW THE AIRFRAME APPEAR WET AND RESPONDING THAT WAY. WE HAD LEVEL 2 ANTI-ICING ON BEFORE THIS CONDITION STARTED AND DURING IT WE PUT LEVEL 3 ON. WE INCREASED PWR TO MAX AND THIS SEEMED TO HELP CTL THE ROLLING TENDENCIES, BUT THE ACFT WAS STILL NOT RESPONDING FULLY. I SAID 'PROPS' AND THE CAPT SAID 'MAX.' I PUSHED THEM UP TO MAX RPM AND THE ACFT STARTED TO BE CTLABLE AGAIN. UNTIL THE PROPS WERE PUSHED TO MAX RPM, I TRULY BELIEVED THAT WE WERE GOING TO IMPACT THE TERRAIN. I DID FORGET TO SAY THAT THE GPWS WAS SAYING 'TERRAIN, TERRAIN...' AFTER GETTING THE ACFT FLYING AGAIN WE CLBED TO 6000' AND GOT RADAR VECTORS FOR A 15 MI FINAL ON THE ILS 8 AND LANDED SAFELY. I THINK WE GOT MASSIVE CLEAR ICING IN THE PROC TURN AND STALLED! THIS ACFT HAS BLACK SPINNERS AND IT'S GREAT TO SEE RIME ICING, BUT NOT CLEAR. ALSO THE SPD FOR CLEAN CONFIGN IN ICING CONDITIONS WITH ACCRETION IS VREF + 60. I THINK TO KEEP THIS AIRPLANE SAFE TO FLY WE NEED SOME INDICATOR TO LET US KNOW WE HAVE ICE ON THE AIRFRAME WE CANNOT SEE. WE ALSO NEED AN INDICATION AURALLY THAT THE SPD HAS GONE BELOW 160 KIAS.

Data retrieved from NASA's ASRS site as of August 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.