Narrative:

BE20 at 16000 ft in light to moderate icing conditions, 15 mi east of ehf on the 105 degree radial, heading 265 degrees, 285 ground track. Aircraft commander was the PF. First pilot was PNF. PIC was talking about icing memos and the aircraft was on autoplt. I was handling the radios, watching the wings and xchking instruments. I saw the airspeed decaying from 180 KIAS to 160 KIAS then 150 KIAS over approximately 2 mins. I checked the wings again. Ice was building slowly. I looked at the airspeed and it was hovering around 143 KTS with a slight growing buffet/vibration and I thought I should interrupt. I saw the trim wheel trimming up, looked at the flight director and saw the command bars above the reference bar and I said to PF, 'you should watch out, the autoplt is going to disconnect.' he moved his hands to the yoke and the aircraft buffeting/vibration increased. I said 'blow the boots' and I saw him look down and push the switch up. I looked to the wings, but there was not enough ice to get a good release. I saw the aircraft yaw and left wing drop 10 degrees. PIC rolled the right wing down and was fighting the aircraft. I looked at the wings and decided that much ice should not cause this much drag or a stall. As I was looking, I noticed his feet were flat on the floor and was causing a cross control stall. I said, 'have you got it? You're cross controling it!' something on the left side of the aircraft was dragging the left wing back. I realized it must be that the propellers were iced up and called out 'propellers are iced up, push them forward!' I saw his hands grab the propeller levers and start to move them. ATC called and asked if we wanted lower as the aircraft was passing through 15000 ft. PIC said 'yes.' and I responded 'yes' to ATC. ATC came back with 'maintain 14000 ft.' I responded '14 thousand, we are having problems here.' I looked at the attitude indicator and saw the aircraft 20 degrees nose down and now right wing 30 degrees low. PIC looked panicked. I said 'easy!' his feet were still not on the rudders. The whole time the aircraft was buffeting and aerodynamic noise was raspy. He said 'propellers forward!' I saw that they weren't forward and pushed them up to maximum. As they reached 2000 RPM, the sound of the air smoothed and the aircraft stopped buffeting. The yaw to the left stopped and the wings went level. I relaxed a little and watched to see if he was now gaining control. Altitude was stabilizing at 14000 ft, but PIC was still fighting the aircraft. I checked the wings and they looked the same. I looked for some kind of drag. The gear handle was up and lights out, no hydraulic pump light, flaps position indicated flaps up. He called 'trim!' I turned the electric trim switch to the 'off' position and looked at the trim wheel. I saw that it was full nose up. I rolled the trim wheel forward and saw that PIC was able to relax a little. I said 'you got it?' he said 'yes.' I scanned the instruments and saw that we were heading almost south. I called 'get back on heading.' (his heading bug was set to 265 degrees.) he began to turn to the right and was able to maintain control of the aircraft. ATC asked if we needed assistance. I waited for a response from PIC -- no response. I said, 'we're ok now,' and ATC replied, 'descend and maintain 10000 ft, contact bakersfield approach.' we had a normal descent and broke out at 11000 ft. All ice was gone and PIC said 'I guess we can pull the propellers back.' I brought the propellers back to 1700 RPM. It was quite silent in the cockpit for a while. From my initial callout to control of aircraft may have been 30-45 seconds. The actual time unknown. My conclusion: I believe that there was a chain of events that led to the loss of control of the aircraft and resulted in a 2000 ft loss of altitude and around 90 degrees loss of heading. I believe that allowing the lower airspds caused the propeller blades to ice up more than before reducing thrust that led to even lower airspeed. The left propeller may have stalled and caused the aircraft to yaw left, causing the left wing to drop. Not using the rudder to counteract the yaw, and by only using aileron to counter roll, increased our drag. With the trim full nose up, PF could not release the yoke with 1 handto roll the trim wheel forward. He was unable to use electric trim or did not think of it at the time. An 'we always go attitude' in front of others, during the preflight conversation indicated that a pilot questioned the afternoon flight in ice. Past discussions from senior pilot indicated that 'professionalism' meant that PIC does not ask for progression, help, or sound in any way that we do not know where we are going or what we are doing. Open charts and posting of approach plates are discouraged. A negative and cynical attitude discourage open discussion. Poor CRM. I felt from his behavior that he didn't want any information or decisions from me. PIC should have paid more attention to flying the aircraft, attentive to aircraft instruments, feet on the rudders and hands on the controls in poor WX, and a safe attitude. Propellers should have been cycled to maximum RPM to ensure ice was not building on the blades. PF should have used rudder to control yaw, not ailerons. I should have been more assertive. I should have declared an emergency and situation to ATC when loss of control of aircraft was evident. I should have called for maximum power and ensured that the propellers were completely forward by following up behind his hands on the propeller control levers, trimming and verifying maximum power on engine instruments. I asked questions in the past about mission management procedures on go/no-go decisions or ice limitations. I was given an angry look and a response of 'what do you mean?' I said that the last place I worked we could not fly in anything more than reported light icing. I was told that we don't have any limitations. Propeller deice boots. An air gap between element and aluminum blade may result in no heat xfer to the aluminum allowing the ice to form sooner on the blade. I think the squat switch/stall vane heat works on ground, but the second element or increased heat doesn't work in-flight. The landing gear squat switch must be raised to check for increased heat.

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Original NASA ASRS Text

Title: THE FLC OF A BE20 ENCOUNTERS ICING AT 16000 FT AND LOSES CTL OF THEIR ACFT, WITH ATC SUGGESTING A LOWER ALT DURING THEIR ALT EXCURSION 15 MI E OF EHF VOR, CA.

Narrative: BE20 AT 16000 FT IN LIGHT TO MODERATE ICING CONDITIONS, 15 MI E OF EHF ON THE 105 DEG RADIAL, HDG 265 DEGS, 285 GND TRACK. ACFT COMMANDER WAS THE PF. FIRST PLT WAS PNF. PIC WAS TALKING ABOUT ICING MEMOS AND THE ACFT WAS ON AUTOPLT. I WAS HANDLING THE RADIOS, WATCHING THE WINGS AND XCHKING INSTS. I SAW THE AIRSPD DECAYING FROM 180 KIAS TO 160 KIAS THEN 150 KIAS OVER APPROX 2 MINS. I CHKED THE WINGS AGAIN. ICE WAS BUILDING SLOWLY. I LOOKED AT THE AIRSPD AND IT WAS HOVERING AROUND 143 KTS WITH A SLIGHT GROWING BUFFET/VIBRATION AND I THOUGHT I SHOULD INTERRUPT. I SAW THE TRIM WHEEL TRIMMING UP, LOOKED AT THE FLT DIRECTOR AND SAW THE COMMAND BARS ABOVE THE REF BAR AND I SAID TO PF, 'YOU SHOULD WATCH OUT, THE AUTOPLT IS GOING TO DISCONNECT.' HE MOVED HIS HANDS TO THE YOKE AND THE ACFT BUFFETING/VIBRATION INCREASED. I SAID 'BLOW THE BOOTS' AND I SAW HIM LOOK DOWN AND PUSH THE SWITCH UP. I LOOKED TO THE WINGS, BUT THERE WAS NOT ENOUGH ICE TO GET A GOOD RELEASE. I SAW THE ACFT YAW AND L WING DROP 10 DEGS. PIC ROLLED THE R WING DOWN AND WAS FIGHTING THE ACFT. I LOOKED AT THE WINGS AND DECIDED THAT MUCH ICE SHOULD NOT CAUSE THIS MUCH DRAG OR A STALL. AS I WAS LOOKING, I NOTICED HIS FEET WERE FLAT ON THE FLOOR AND WAS CAUSING A CROSS CTL STALL. I SAID, 'HAVE YOU GOT IT? YOU'RE CROSS CTLING IT!' SOMETHING ON THE L SIDE OF THE ACFT WAS DRAGGING THE L WING BACK. I REALIZED IT MUST BE THAT THE PROPS WERE ICED UP AND CALLED OUT 'PROPS ARE ICED UP, PUSH THEM FORWARD!' I SAW HIS HANDS GRAB THE PROP LEVERS AND START TO MOVE THEM. ATC CALLED AND ASKED IF WE WANTED LOWER AS THE ACFT WAS PASSING THROUGH 15000 FT. PIC SAID 'YES.' AND I RESPONDED 'YES' TO ATC. ATC CAME BACK WITH 'MAINTAIN 14000 FT.' I RESPONDED '14 THOUSAND, WE ARE HAVING PROBS HERE.' I LOOKED AT THE ATTITUDE INDICATOR AND SAW THE ACFT 20 DEGS NOSE DOWN AND NOW R WING 30 DEGS LOW. PIC LOOKED PANICKED. I SAID 'EASY!' HIS FEET WERE STILL NOT ON THE RUDDERS. THE WHOLE TIME THE ACFT WAS BUFFETING AND AERODYNAMIC NOISE WAS RASPY. HE SAID 'PROPS FORWARD!' I SAW THAT THEY WEREN'T FORWARD AND PUSHED THEM UP TO MAX. AS THEY REACHED 2000 RPM, THE SOUND OF THE AIR SMOOTHED AND THE ACFT STOPPED BUFFETING. THE YAW TO THE L STOPPED AND THE WINGS WENT LEVEL. I RELAXED A LITTLE AND WATCHED TO SEE IF HE WAS NOW GAINING CTL. ALT WAS STABILIZING AT 14000 FT, BUT PIC WAS STILL FIGHTING THE ACFT. I CHKED THE WINGS AND THEY LOOKED THE SAME. I LOOKED FOR SOME KIND OF DRAG. THE GEAR HANDLE WAS UP AND LIGHTS OUT, NO HYD PUMP LIGHT, FLAPS POS INDICATED FLAPS UP. HE CALLED 'TRIM!' I TURNED THE ELECTRIC TRIM SWITCH TO THE 'OFF' POS AND LOOKED AT THE TRIM WHEEL. I SAW THAT IT WAS FULL NOSE UP. I ROLLED THE TRIM WHEEL FORWARD AND SAW THAT PIC WAS ABLE TO RELAX A LITTLE. I SAID 'YOU GOT IT?' HE SAID 'YES.' I SCANNED THE INSTS AND SAW THAT WE WERE HDG ALMOST S. I CALLED 'GET BACK ON HDG.' (HIS HDG BUG WAS SET TO 265 DEGS.) HE BEGAN TO TURN TO THE R AND WAS ABLE TO MAINTAIN CTL OF THE ACFT. ATC ASKED IF WE NEEDED ASSISTANCE. I WAITED FOR A RESPONSE FROM PIC -- NO RESPONSE. I SAID, 'WE'RE OK NOW,' AND ATC REPLIED, 'DSND AND MAINTAIN 10000 FT, CONTACT BAKERSFIELD APCH.' WE HAD A NORMAL DSCNT AND BROKE OUT AT 11000 FT. ALL ICE WAS GONE AND PIC SAID 'I GUESS WE CAN PULL THE PROPS BACK.' I BROUGHT THE PROPS BACK TO 1700 RPM. IT WAS QUITE SILENT IN THE COCKPIT FOR A WHILE. FROM MY INITIAL CALLOUT TO CTL OF ACFT MAY HAVE BEEN 30-45 SECONDS. THE ACTUAL TIME UNKNOWN. MY CONCLUSION: I BELIEVE THAT THERE WAS A CHAIN OF EVENTS THAT LED TO THE LOSS OF CTL OF THE ACFT AND RESULTED IN A 2000 FT LOSS OF ALT AND AROUND 90 DEGS LOSS OF HDG. I BELIEVE THAT ALLOWING THE LOWER AIRSPDS CAUSED THE PROP BLADES TO ICE UP MORE THAN BEFORE REDUCING THRUST THAT LED TO EVEN LOWER AIRSPD. THE L PROP MAY HAVE STALLED AND CAUSED THE ACFT TO YAW L, CAUSING THE L WING TO DROP. NOT USING THE RUDDER TO COUNTERACT THE YAW, AND BY ONLY USING AILERON TO COUNTER ROLL, INCREASED OUR DRAG. WITH THE TRIM FULL NOSE UP, PF COULD NOT RELEASE THE YOKE WITH 1 HANDTO ROLL THE TRIM WHEEL FORWARD. HE WAS UNABLE TO USE ELECTRIC TRIM OR DID NOT THINK OF IT AT THE TIME. AN 'WE ALWAYS GO ATTITUDE' IN FRONT OF OTHERS, DURING THE PREFLT CONVERSATION INDICATED THAT A PLT QUESTIONED THE AFTERNOON FLT IN ICE. PAST DISCUSSIONS FROM SENIOR PLT INDICATED THAT 'PROFESSIONALISM' MEANT THAT PIC DOES NOT ASK FOR PROGRESSION, HELP, OR SOUND IN ANY WAY THAT WE DO NOT KNOW WHERE WE ARE GOING OR WHAT WE ARE DOING. OPEN CHARTS AND POSTING OF APCH PLATES ARE DISCOURAGED. A NEGATIVE AND CYNICAL ATTITUDE DISCOURAGE OPEN DISCUSSION. POOR CRM. I FELT FROM HIS BEHAVIOR THAT HE DIDN'T WANT ANY INFO OR DECISIONS FROM ME. PIC SHOULD HAVE PAID MORE ATTN TO FLYING THE ACFT, ATTENTIVE TO ACFT INSTS, FEET ON THE RUDDERS AND HANDS ON THE CTLS IN POOR WX, AND A SAFE ATTITUDE. PROPS SHOULD HAVE BEEN CYCLED TO MAX RPM TO ENSURE ICE WAS NOT BUILDING ON THE BLADES. PF SHOULD HAVE USED RUDDER TO CTL YAW, NOT AILERONS. I SHOULD HAVE BEEN MORE ASSERTIVE. I SHOULD HAVE DECLARED AN EMER AND SIT TO ATC WHEN LOSS OF CTL OF ACFT WAS EVIDENT. I SHOULD HAVE CALLED FOR MAX PWR AND ENSURED THAT THE PROPS WERE COMPLETELY FORWARD BY FOLLOWING UP BEHIND HIS HANDS ON THE PROP CTL LEVERS, TRIMMING AND VERIFYING MAX PWR ON ENG INSTS. I ASKED QUESTIONS IN THE PAST ABOUT MISSION MGMNT PROCS ON GO/NO-GO DECISIONS OR ICE LIMITATIONS. I WAS GIVEN AN ANGRY LOOK AND A RESPONSE OF 'WHAT DO YOU MEAN?' I SAID THAT THE LAST PLACE I WORKED WE COULD NOT FLY IN ANYTHING MORE THAN RPTED LIGHT ICING. I WAS TOLD THAT WE DON'T HAVE ANY LIMITATIONS. PROP DEICE BOOTS. AN AIR GAP BTWN ELEMENT AND ALUMINUM BLADE MAY RESULT IN NO HEAT XFER TO THE ALUMINUM ALLOWING THE ICE TO FORM SOONER ON THE BLADE. I THINK THE SQUAT SWITCH/STALL VANE HEAT WORKS ON GND, BUT THE SECOND ELEMENT OR INCREASED HEAT DOESN'T WORK INFLT. THE LNDG GEAR SQUAT SWITCH MUST BE RAISED TO CHK FOR INCREASED HEAT.

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.