Narrative:

The following event occurred on apr/xa/99. I am a first officer on a part 135 operated embraer bandeirante (E110). We departed columbus, in (bak) at AB30 for a flight to kansas city (mci). En route we were advised of a line of severe thunderstorms extending as far south as oklahoma city and 200 mi north of our route. After a delay on the ground at chillicothe (cht) of approximately 1 hour 10 mins, the flight continued to mci uneventfully. At AE50, we departed mci for columbus, oh (cmh). The line of thunderstorms had dissipated rapidly as it moved northeast. Climbing to 9000 ft MSL, we could see we would be flying through some of the tops of the clouds. Outside air temperature was -2 degrees C. In the clouds we encountered rapid ice accumulation. The enclosed pictures clearly show the conditions of flight, in the clouds for 30 seconds to 1 min at a time. In these brief periods, we accumulated the mixed ice shown. With the sun shining, the ice accumulation behind the protected area of the wing can be clearly seen. The accompanying photo is of the mid to side window in the cockpit. In the highlighted area, sld has streamed back as much as 5 inches before freezing occurred. This runback corresponds with the ice shape pictured on the wings. The importance of this event is that in conditions of rime icing, the E110 forms ice strictly on the front windshield and only on protected areas of the wing surfaces. The clear component of mixed ice, however, streams back along the windshield before freezing. It may be a good indicator of ice accumulation behind protected areas of the wing when side window ice forms on the bandeirante. It may be an important training point for pilots flying similar aircraft with curved windshields to take note exactly where ice typically forms on their aircraft in relation to visual cues inside the cockpit. This should be stressed even more for those operating larger aircraft where the wings cannot be seen from the cockpit. In these aircraft, a crew member is unable to visually confirm areas of accumulation, but must rely on other cues and a certain amount of guesswork as to amount of ice and areas of coverage. These pilots should possibly have a point on the windshield where, if ice has accumulated to, or beyond this point, he could assume with a fair amount of accuracy there is ice on unprotected areas of airfoil surfaces. This report is to show side window ice as an indicator for icing conditions beyond the capabilities of the E110 bandeirante. For the purpose of pilot training and awareness perhaps other aircraft should be examined for similar characteristics. As a result of the previously described icing conditions, the bandeirante develops adverse flight control responses rather quickly. On a flight may/xa/99 from mdt to mke cruising at 10000 ft MSL, we again encountered mixed icing conditions with sld streaming back solidly to the black line on the preceding picture. I was the PF. While I discussed a plan with the captain, we accumulated about 1/2 - 3/4 of an inch of ice. (This was approximately 3-4 mins time). As we requested lower, the tail began to flutter mildly. All through the descent, until we shed the ice at 7000 ft MSL, the control yoke was in a lazy back and forth movement with a loose feeling. It seemed to move about 1 inch or a little greater. I believe had we continued flight in those conditions, we would have had a full blown tail stall in a matter of mins. The bandeirante is an airplane that will handle this amount of rime ice without any control changes. However, it appears when just a small amount of ice proceeds beyond the de-ice boots, the airplane reacts very poorly. I would again like to stress the relation between the ice forming on the side window and ice behind the boots. I also personally relate side window icing to conditions extremely favorable to a tail stall.

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Original NASA ASRS Text

Title: AN ATX E110 FO RPT ON ICE ACCUMULATION ON THE SIDE WINDOWS AND IT BEING INDICATIVE OF WHAT AMOUNT OF ICING IS BEING ACCUMULATED ON THE WING AND TAIL LEADING EDGES.

Narrative: THE FOLLOWING EVENT OCCURRED ON APR/XA/99. I AM A FO ON A PART 135 OPERATED EMBRAER BANDEIRANTE (E110). WE DEPARTED COLUMBUS, IN (BAK) AT AB30 FOR A FLT TO KANSAS CITY (MCI). ENRTE WE WERE ADVISED OF A LINE OF SEVERE TSTMS EXTENDING AS FAR S AS OKLAHOMA CITY AND 200 MI N OF OUR RTE. AFTER A DELAY ON THE GND AT CHILLICOTHE (CHT) OF APPROX 1 HR 10 MINS, THE FLT CONTINUED TO MCI UNEVENTFULLY. AT AE50, WE DEPARTED MCI FOR COLUMBUS, OH (CMH). THE LINE OF TSTMS HAD DISSIPATED RAPIDLY AS IT MOVED NE. CLBING TO 9000 FT MSL, WE COULD SEE WE WOULD BE FLYING THROUGH SOME OF THE TOPS OF THE CLOUDS. OUTSIDE AIR TEMP WAS -2 DEGS C. IN THE CLOUDS WE ENCOUNTERED RAPID ICE ACCUMULATION. THE ENCLOSED PICTURES CLRLY SHOW THE CONDITIONS OF FLT, IN THE CLOUDS FOR 30 SECONDS TO 1 MIN AT A TIME. IN THESE BRIEF PERIODS, WE ACCUMULATED THE MIXED ICE SHOWN. WITH THE SUN SHINING, THE ICE ACCUMULATION BEHIND THE PROTECTED AREA OF THE WING CAN BE CLRLY SEEN. THE ACCOMPANYING PHOTO IS OF THE MID TO SIDE WINDOW IN THE COCKPIT. IN THE HIGHLIGHTED AREA, SLD HAS STREAMED BACK AS MUCH AS 5 INCHES BEFORE FREEZING OCCURRED. THIS RUNBACK CORRESPONDS WITH THE ICE SHAPE PICTURED ON THE WINGS. THE IMPORTANCE OF THIS EVENT IS THAT IN CONDITIONS OF RIME ICING, THE E110 FORMS ICE STRICTLY ON THE FRONT WINDSHIELD AND ONLY ON PROTECTED AREAS OF THE WING SURFACES. THE CLR COMPONENT OF MIXED ICE, HOWEVER, STREAMS BACK ALONG THE WINDSHIELD BEFORE FREEZING. IT MAY BE A GOOD INDICATOR OF ICE ACCUMULATION BEHIND PROTECTED AREAS OF THE WING WHEN SIDE WINDOW ICE FORMS ON THE BANDEIRANTE. IT MAY BE AN IMPORTANT TRAINING POINT FOR PLTS FLYING SIMILAR ACFT WITH CURVED WINDSHIELDS TO TAKE NOTE EXACTLY WHERE ICE TYPICALLY FORMS ON THEIR ACFT IN RELATION TO VISUAL CUES INSIDE THE COCKPIT. THIS SHOULD BE STRESSED EVEN MORE FOR THOSE OPERATING LARGER ACFT WHERE THE WINGS CANNOT BE SEEN FROM THE COCKPIT. IN THESE ACFT, A CREW MEMBER IS UNABLE TO VISUALLY CONFIRM AREAS OF ACCUMULATION, BUT MUST RELY ON OTHER CUES AND A CERTAIN AMOUNT OF GUESSWORK AS TO AMOUNT OF ICE AND AREAS OF COVERAGE. THESE PLTS SHOULD POSSIBLY HAVE A POINT ON THE WINDSHIELD WHERE, IF ICE HAS ACCUMULATED TO, OR BEYOND THIS POINT, HE COULD ASSUME WITH A FAIR AMOUNT OF ACCURACY THERE IS ICE ON UNPROTECTED AREAS OF AIRFOIL SURFACES. THIS RPT IS TO SHOW SIDE WINDOW ICE AS AN INDICATOR FOR ICING CONDITIONS BEYOND THE CAPABILITIES OF THE E110 BANDEIRANTE. FOR THE PURPOSE OF PLT TRAINING AND AWARENESS PERHAPS OTHER ACFT SHOULD BE EXAMINED FOR SIMILAR CHARACTERISTICS. AS A RESULT OF THE PREVIOUSLY DESCRIBED ICING CONDITIONS, THE BANDEIRANTE DEVELOPS ADVERSE FLT CTL RESPONSES RATHER QUICKLY. ON A FLT MAY/XA/99 FROM MDT TO MKE CRUISING AT 10000 FT MSL, WE AGAIN ENCOUNTERED MIXED ICING CONDITIONS WITH SLD STREAMING BACK SOLIDLY TO THE BLACK LINE ON THE PRECEDING PICTURE. I WAS THE PF. WHILE I DISCUSSED A PLAN WITH THE CAPT, WE ACCUMULATED ABOUT 1/2 - 3/4 OF AN INCH OF ICE. (THIS WAS APPROX 3-4 MINS TIME). AS WE REQUESTED LOWER, THE TAIL BEGAN TO FLUTTER MILDLY. ALL THROUGH THE DSCNT, UNTIL WE SHED THE ICE AT 7000 FT MSL, THE CTL YOKE WAS IN A LAZY BACK AND FORTH MOVEMENT WITH A LOOSE FEELING. IT SEEMED TO MOVE ABOUT 1 INCH OR A LITTLE GREATER. I BELIEVE HAD WE CONTINUED FLT IN THOSE CONDITIONS, WE WOULD HAVE HAD A FULL BLOWN TAIL STALL IN A MATTER OF MINS. THE BANDEIRANTE IS AN AIRPLANE THAT WILL HANDLE THIS AMOUNT OF RIME ICE WITHOUT ANY CTL CHANGES. HOWEVER, IT APPEARS WHEN JUST A SMALL AMOUNT OF ICE PROCEEDS BEYOND THE DE-ICE BOOTS, THE AIRPLANE REACTS VERY POORLY. I WOULD AGAIN LIKE TO STRESS THE RELATION BTWN THE ICE FORMING ON THE SIDE WINDOW AND ICE BEHIND THE BOOTS. I ALSO PERSONALLY RELATE SIDE WINDOW ICING TO CONDITIONS EXTREMELY FAVORABLE TO A TAIL STALL.

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.