Narrative:

Shortly after leveling off, the crew briefed about the route to gfk, existing WX conditions en route and thunderstorm avoidance procedures. Upon completion of this discussion, the instructor pilot switched seats with the PNF, leaving the 2 interns up front and the ip in the back. The approximately course was 280-290 degrees and en route conditions at FL200 were VMC, the crew had clearance from ATC to deviate as necessary to avoid buildups. In the distance ahead, the crew visually idented a group of buildups and verified their position with the on board WX radar using the 100 NM range. At this time the crew began discussing the avoidance procedure to be used. Crew contacted ZAU to ask what their radar was showing. ZAU replied that his radar showed nothing, but said that ZMP would have a better picture of the conditions and then handed us off to ZMP. Upon contacting ZMP, they verified the cells ahead. Center then recommended a deviation to the north, saying that his radar showed nothing in that area and that a turn to the right would be a more direct course to gfk. (Our approximately position at this time was south of janesville on a heading of 270-290 degrees. We were on a vector heading to gfk with clearance to deviation as necessary for buildups.) at FL200 and still in VMC conditions, to our right we could see a thin layer of clouds, but clear above. Visually and by radar we saw nothing except the thin layer to our right. The decision was made to turn right 10-15 degrees to avoid the buildup ahead, now showing on the radar at the 60-80 NM range. The turn was made visually and the wings were level prior to entering the thin layer of clouds. Entry was made at the top of the layer to IMC conditions. Once in the clouds, the air was still smooth, then suddenly we encountered 1-2 bumps of light chop. The airspeed was approximately 170 KTS and no fluctuations in speed were noted. Immediately we found ourselves in a nose low pitch attitude. Ice covered the windshield, and at this time due to severe turbulence, the PF's gyros tumbled which caused the autoplt to malfunction. PF disconnected the ap, seeing that his gyros had tumbled leaving unreliable instruments, transfers control to the other pilot who assumed control and reduced the power to idle simultaneously. At this time, the vertical speed was indicating a 3000 FPM loss and the airspeed indicator was at the barber pole. During this time the attitude indicator began operating and crew got ground contact out the right window at approximately 17000-16800 ft MSL. Pilot a referenced his attitude indicator to indicate a right bank of approximately 45 degrees. During this time, pilot a was still in control of the aircraft, keeping the ball centered, allowing the airplane to decelerate in the bank. Pilot B realizes the situation, assumes control of the aircraft from a. At zero vertical speed, B levels the wings and begins to add power. Positive control of the aircraft was regained between 17000-16800 ft MSL and the PF elected to continue to let the airplane decelerate in a slow descent. Upon position control, pilot B advised the ip to contact ATC and to report we were descending to 15000 ft due to severe turbulence. On the 1ST attempt to contact ATC there was no response. Upon contact with ATC, the ip reported severe turbulence and that we were now level at 15000. The PF asked for clearance to 12000 ft to good VMC conditions. At this time ATC asked if we needed any help, the ip replied negative -- everything was ok. The flight continued to gfk, without any other abnormalities. The flight arrived at gfk and after completion of post flight and securing, maintenance was advised of what had occurred. Maintenance inspected the aircraft and released it for flight. Later during a detail inspection, problems were found with the aircraft. I do not feel that the control inputs during the recovery were in such a manner to overstress the aircraft. The crew used standard unusual attitude recovery techniques taught at training.

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Original NASA ASRS Text

Title: FLC OF BEECH KING AIR LOST CTL DUE TO SEVERE TURB RESULTING IN DEV FROM ASSIGNED ALT.

Narrative: SHORTLY AFTER LEVELING OFF, THE CREW BRIEFED ABOUT THE RTE TO GFK, EXISTING WX CONDITIONS ENRTE AND TSTM AVOIDANCE PROCS. UPON COMPLETION OF THIS DISCUSSION, THE INSTRUCTOR PLT SWITCHED SEATS WITH THE PNF, LEAVING THE 2 INTERNS UP FRONT AND THE IP IN THE BACK. THE APPROX COURSE WAS 280-290 DEGS AND ENRTE CONDITIONS AT FL200 WERE VMC, THE CREW HAD CLRNC FROM ATC TO DEVIATE AS NECESSARY TO AVOID BUILDUPS. IN THE DISTANCE AHEAD, THE CREW VISUALLY IDENTED A GROUP OF BUILDUPS AND VERIFIED THEIR POS WITH THE ON BOARD WX RADAR USING THE 100 NM RANGE. AT THIS TIME THE CREW BEGAN DISCUSSING THE AVOIDANCE PROC TO BE USED. CREW CONTACTED ZAU TO ASK WHAT THEIR RADAR WAS SHOWING. ZAU REPLIED THAT HIS RADAR SHOWED NOTHING, BUT SAID THAT ZMP WOULD HAVE A BETTER PICTURE OF THE CONDITIONS AND THEN HANDED US OFF TO ZMP. UPON CONTACTING ZMP, THEY VERIFIED THE CELLS AHEAD. CTR THEN RECOMMENDED A DEV TO THE N, SAYING THAT HIS RADAR SHOWED NOTHING IN THAT AREA AND THAT A TURN TO THE R WOULD BE A MORE DIRECT COURSE TO GFK. (OUR APPROX POS AT THIS TIME WAS S OF JANESVILLE ON A HDG OF 270-290 DEGS. WE WERE ON A VECTOR HDG TO GFK WITH CLRNC TO DEV AS NECESSARY FOR BUILDUPS.) AT FL200 AND STILL IN VMC CONDITIONS, TO OUR R WE COULD SEE A THIN LAYER OF CLOUDS, BUT CLR ABOVE. VISUALLY AND BY RADAR WE SAW NOTHING EXCEPT THE THIN LAYER TO OUR R. THE DECISION WAS MADE TO TURN R 10-15 DEGS TO AVOID THE BUILDUP AHEAD, NOW SHOWING ON THE RADAR AT THE 60-80 NM RANGE. THE TURN WAS MADE VISUALLY AND THE WINGS WERE LEVEL PRIOR TO ENTERING THE THIN LAYER OF CLOUDS. ENTRY WAS MADE AT THE TOP OF THE LAYER TO IMC CONDITIONS. ONCE IN THE CLOUDS, THE AIR WAS STILL SMOOTH, THEN SUDDENLY WE ENCOUNTERED 1-2 BUMPS OF LIGHT CHOP. THE AIRSPD WAS APPROX 170 KTS AND NO FLUCTUATIONS IN SPD WERE NOTED. IMMEDIATELY WE FOUND OURSELVES IN A NOSE LOW PITCH ATTITUDE. ICE COVERED THE WINDSHIELD, AND AT THIS TIME DUE TO SEVERE TURB, THE PF'S GYROS TUMBLED WHICH CAUSED THE AUTOPLT TO MALFUNCTION. PF DISCONNECTED THE AP, SEEING THAT HIS GYROS HAD TUMBLED LEAVING UNRELIABLE INSTS, TRANSFERS CTL TO THE OTHER PLT WHO ASSUMED CTL AND REDUCED THE PWR TO IDLE SIMULTANEOUSLY. AT THIS TIME, THE VERT SPD WAS INDICATING A 3000 FPM LOSS AND THE AIRSPD INDICATOR WAS AT THE BARBER POLE. DURING THIS TIME THE ATTITUDE INDICATOR BEGAN OPERATING AND CREW GOT GND CONTACT OUT THE R WINDOW AT APPROX 17000-16800 FT MSL. PLT A REFERENCED HIS ATTITUDE INDICATOR TO INDICATE A R BANK OF APPROX 45 DEGS. DURING THIS TIME, PLT A WAS STILL IN CTL OF THE ACFT, KEEPING THE BALL CTRED, ALLOWING THE AIRPLANE TO DECELERATE IN THE BANK. PLT B REALIZES THE SIT, ASSUMES CTL OF THE ACFT FROM A. AT ZERO VERT SPD, B LEVELS THE WINGS AND BEGINS TO ADD PWR. POSITIVE CTL OF THE ACFT WAS REGAINED BTWN 17000-16800 FT MSL AND THE PF ELECTED TO CONTINUE TO LET THE AIRPLANE DECELERATE IN A SLOW DSCNT. UPON POS CTL, PLT B ADVISED THE IP TO CONTACT ATC AND TO RPT WE WERE DSNDING TO 15000 FT DUE TO SEVERE TURB. ON THE 1ST ATTEMPT TO CONTACT ATC THERE WAS NO RESPONSE. UPON CONTACT WITH ATC, THE IP RPTED SEVERE TURB AND THAT WE WERE NOW LEVEL AT 15000. THE PF ASKED FOR CLRNC TO 12000 FT TO GOOD VMC CONDITIONS. AT THIS TIME ATC ASKED IF WE NEEDED ANY HELP, THE IP REPLIED NEGATIVE -- EVERYTHING WAS OK. THE FLT CONTINUED TO GFK, WITHOUT ANY OTHER ABNORMALITIES. THE FLT ARRIVED AT GFK AND AFTER COMPLETION OF POST FLT AND SECURING, MAINT WAS ADVISED OF WHAT HAD OCCURRED. MAINT INSPECTED THE ACFT AND RELEASED IT FOR FLT. LATER DURING A DETAIL INSPECTION, PROBS WERE FOUND WITH THE ACFT. I DO NOT FEEL THAT THE CTL INPUTS DURING THE RECOVERY WERE IN SUCH A MANNER TO OVERSTRESS THE ACFT. THE CREW USED STANDARD UNUSUAL ATTITUDE RECOVERY TECHNIQUES TAUGHT AT TRAINING.

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.