Number 234
December 1998
The Ice Cometh
This is the time of year when many pilots are gearing up for the increased likelihood of encountering in-flight icing. Our first reporter believed that an airplane “certified for flight into known icing” could handle a routine IFR flight. I declared an emergency with Approach Control. With the increased power and resultant airspeed, and continuous cycling of the boots, I got the plane stabilized. Approach Control provided vectors for the ILS approach at XYZ. We experienced no further difficulty flying the approach. [On post-flight], there was about one-quarter inch of ice remaining on the nose, spinners, upper portion of the tail and other unprotected areas. I assume significant ice was shed while descending. I have become an even more cautious flight planner. I now know first-hand that icing conditions are unpredictable and how severe localized icing can be—it can quickly overpower a “known icing” aircraft.
s [On arrival], prior to cloud penetration, all [anti-ice]
systems engaged. I continued checking the leading edges of wings and spinners—no significant accumulation noted. Level at 3,000 feet at about 140 knots, the airplane began to buffet, elevator response became mushy, and it appeared the plane was ready to stall. When I reached to add more power, the airplane nosed over and began to turn. I went with the turn, trading altitude for airspeed, and cycled the deicing boots.
Ice-Bound
Loss of aircraft control due to the weight of ice and the disruption of airflow over the wings and elevator surfaces is only one part of the icing story. Ice accumulation can also cause jamming or malfunction of controls and components, as an air carrier First Officer reports: degrees prior to heading, I was sure it was not going to roll out. I disconnected and attempted to manually roll out. It took considerable force to move the yoke. With more force and about two-thirds deflection (considerably more than normal), the controls appeared to break free. After this, the aircraft responded and flew normally. We landed uneventfully. Maintenance inspected, detected, and removed ice from the control cables and pulleys. The reporter surmised that the previous night’s rain and wind had blown water into the control unit housings, where the water froze, causing the controls to jam.
s I was flying the aircraft on autopilot. The flight had been normal and uneventful. During approach, ATC gave us a descent, a turn, and a speed reduction. After establishing the descent and turn, I extended the speed brakes to start slowing. The speed brakes felt stiff going past one-third extension, so I retracted and re-extended, and they felt normal the second time. The autopilot did not appear to roll out. I watched it closely and by 5
“Get-There-Itis”
A General Aviation pilot debated filing an IFR flight plan for a pleasure flight in mixed VMC/IMC. The reporter even considered canceling the flight because of the weather, but admits that “my judgment was clouded by ‘get-there-itis’ combined with beckoning patches of blue sky.” frozen over. As we were climbing, the airspeed indicator was falsely reading a higher and higher airspeed, and I was gradually compensating (unaware) to stay at Vx indicated airspeed. The plane then began to porpoise, indicating an imminent stall. Just as the stall broke hard, the scenario came together in my mind. We banked at least 90 degrees, and I pushed the yoke forward... I pulled the throttle back to idle, and recovered from the stall in solid IMC. I did a 180 turn and headed for VMC. We broke out in a few minutes and landed VFR. The pitot tube didn’t thaw out until we got below the freezing level... I am convinced that the surging engine was due to the high pitch attitude. The reporter points out several lessons to be learned from this incident: Check the pitot heat before any flight which has the potential to be in IMC, and carefully monitor weight and balance for aft-of-limit conditions that may hamper stall recovery. Finally, avoid the beckoning lure of those “blue patches” between clouds. October 1998 Report Intake
Air Carrier/Air Taxi Pilots General Aviation Pilots Controllers Cabin/Mechanics/Military/Other 2035 798 65 168
s After considering the options, I decided that flying VFR would allow me the freedom to find a hole in the clouds and get on top in clear air. As we climbed toward the blue patches, it seemed harder and harder to find a hole large enough to climb through. Since it looked like we only needed to climb about another 100 feet to clear the tops, I decided that I would plow on through. Things got worse.
At first the sun poked through occasionally, beckoning us on. Then it started getting darker, and we picked up a trace of rime ice. Just as I was deciding that we would have to turn back, the engine started surging. I thought carb ice, but carb heat didn’t help. As I was trouble-shooting the engine, another aviation demon was sneaking up on us. It turned out that the pitot heat was inoperative, and the pitot tube had ASRS Recently Issued Alerts On...
BA-32 hydraulic pressure loss CL-601 brake failure on landing Restraint procedures during air transport of prisoners Cargo door failure and rapid decompression on a DA-20 TCAS II alerts attributed to a transponder on a Texas building
A Monthly Safety Bulletin from The Office of the NASA Aviation Safety Reporting System, P.O. Box 189, Moffett Field, CA 94035-0189
http://olias.arc.nasa.gov/asrs
TOTAL
3066
飞行翻译公司 www.aviation.cn 本文链接地址：美国ASRS安全公告CALLBACK cb_234.pdf
December 1998
The Ice Cometh
This is the time of year when many pilots are gearing up for the increased likelihood of encountering in-flight icing. Our first reporter believed that an airplane “certified for flight into known icing” could handle a routine IFR flight. I declared an emergency with Approach Control. With the increased power and resultant airspeed, and continuous cycling of the boots, I got the plane stabilized. Approach Control provided vectors for the ILS approach at XYZ. We experienced no further difficulty flying the approach. [On post-flight], there was about one-quarter inch of ice remaining on the nose, spinners, upper portion of the tail and other unprotected areas. I assume significant ice was shed while descending. I have become an even more cautious flight planner. I now know first-hand that icing conditions are unpredictable and how severe localized icing can be—it can quickly overpower a “known icing” aircraft.
s [On arrival], prior to cloud penetration, all [anti-ice]
systems engaged. I continued checking the leading edges of wings and spinners—no significant accumulation noted. Level at 3,000 feet at about 140 knots, the airplane began to buffet, elevator response became mushy, and it appeared the plane was ready to stall. When I reached to add more power, the airplane nosed over and began to turn. I went with the turn, trading altitude for airspeed, and cycled the deicing boots.
Ice-Bound
Loss of aircraft control due to the weight of ice and the disruption of airflow over the wings and elevator surfaces is only one part of the icing story. Ice accumulation can also cause jamming or malfunction of controls and components, as an air carrier First Officer reports: degrees prior to heading, I was sure it was not going to roll out. I disconnected and attempted to manually roll out. It took considerable force to move the yoke. With more force and about two-thirds deflection (considerably more than normal), the controls appeared to break free. After this, the aircraft responded and flew normally. We landed uneventfully. Maintenance inspected, detected, and removed ice from the control cables and pulleys. The reporter surmised that the previous night’s rain and wind had blown water into the control unit housings, where the water froze, causing the controls to jam.
s I was flying the aircraft on autopilot. The flight had been normal and uneventful. During approach, ATC gave us a descent, a turn, and a speed reduction. After establishing the descent and turn, I extended the speed brakes to start slowing. The speed brakes felt stiff going past one-third extension, so I retracted and re-extended, and they felt normal the second time. The autopilot did not appear to roll out. I watched it closely and by 5
“Get-There-Itis”
A General Aviation pilot debated filing an IFR flight plan for a pleasure flight in mixed VMC/IMC. The reporter even considered canceling the flight because of the weather, but admits that “my judgment was clouded by ‘get-there-itis’ combined with beckoning patches of blue sky.” frozen over. As we were climbing, the airspeed indicator was falsely reading a higher and higher airspeed, and I was gradually compensating (unaware) to stay at Vx indicated airspeed. The plane then began to porpoise, indicating an imminent stall. Just as the stall broke hard, the scenario came together in my mind. We banked at least 90 degrees, and I pushed the yoke forward... I pulled the throttle back to idle, and recovered from the stall in solid IMC. I did a 180 turn and headed for VMC. We broke out in a few minutes and landed VFR. The pitot tube didn’t thaw out until we got below the freezing level... I am convinced that the surging engine was due to the high pitch attitude. The reporter points out several lessons to be learned from this incident: Check the pitot heat before any flight which has the potential to be in IMC, and carefully monitor weight and balance for aft-of-limit conditions that may hamper stall recovery. Finally, avoid the beckoning lure of those “blue patches” between clouds. October 1998 Report Intake
Air Carrier/Air Taxi Pilots General Aviation Pilots Controllers Cabin/Mechanics/Military/Other 2035 798 65 168
s After considering the options, I decided that flying VFR would allow me the freedom to find a hole in the clouds and get on top in clear air. As we climbed toward the blue patches, it seemed harder and harder to find a hole large enough to climb through. Since it looked like we only needed to climb about another 100 feet to clear the tops, I decided that I would plow on through. Things got worse.
At first the sun poked through occasionally, beckoning us on. Then it started getting darker, and we picked up a trace of rime ice. Just as I was deciding that we would have to turn back, the engine started surging. I thought carb ice, but carb heat didn’t help. As I was trouble-shooting the engine, another aviation demon was sneaking up on us. It turned out that the pitot heat was inoperative, and the pitot tube had ASRS Recently Issued Alerts On...
BA-32 hydraulic pressure loss CL-601 brake failure on landing Restraint procedures during air transport of prisoners Cargo door failure and rapid decompression on a DA-20 TCAS II alerts attributed to a transponder on a Texas building
A Monthly Safety Bulletin from The Office of the NASA Aviation Safety Reporting System, P.O. Box 189, Moffett Field, CA 94035-0189
http://olias.arc.nasa.gov/asrs
TOTAL
3066
飞行翻译公司 www.aviation.cn 本文链接地址：美国ASRS安全公告CALLBACK cb_234.pdf
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