Number 278
November 2002
While there have only been scattered flurries of weatherrelated ASRS reports recently, the forecast is for increasing intensity over the next few months. On the brighter side, ASRS Analysts do see a chance for significant clearing of embedded gray cells and foggy
memories provided there is heavy participation in a review of cold weather operations and procedures. A high absorption rate of the towering accumulation of lessons learned could prevent an avalanche of reports at ASRS.
“…We were going to have to find the runway regardless of the weather”
This “chilling” statement reflects the gravity of the situation encountered by an instructor and student in an ice-encumbered Cessna 172. Knowing the limitations of one’s aircraft and having a respect for the forces of nature are two universal lessons learned by the instructor who submitted this report. said, “You probably know this, but I’m getting an altitude alert...” We briefed the approach and knew we were going to have to find the runway regardless of the weather... We saw the approach lights at about 400 feet AGL, almost 500 feet below the localizer approach minimums. We landed without incident (with two inches of ice). The approach and tower controllers were extremely helpful. Causes: We took off into forecast icing conditions… I thought if we could get up high enough (10,000 feet) we could fly over the icing layer… Even a very thin layer of ice on the leading edge and upper wing surfaces can cause a dramatic loss of lift and increase in drag. With two inches of ice, these pilots were lucky to be near an airport.
s The [Cessna 172] began to accumulate light rime ice in
cruise at 10,000 feet… Icing became increasingly heavier until…we were having difficulty maintaining altitude. Departure [said] he needed us to maintain 10,000 feet. I told him we were picking up ice and requested vectors [to the] ILS Runway 35 at XXX… We checked in with the Tower [and we were] cleared to land. Icing was moderate at that point. We had full throttle at 70 KIAS and [we were] descending 400 feet per minute. We were unable to maintain approach minimums, and at one point Tower
Cool Controller Stops a Snowballing Situation
Quick work by a sharp Center Controller not only helped an MD-80 crew out of a bad situation, but also prevented a “chain reaction” of traffic conflicts. This first report gives the Controller’s perspective. And the following report details the pilot’s view of the same incident:
s …Aircraft was in cruise flight at FL350 with airfoil
and engine anti-ice on. [We were] in IMC deviating to the east of thunderstorms. Aircraft speed increased initially from .76 to .78 Mach, then deteriorated to .69 Mach. Performance did not increase so we immediately descended to a lower altitude to regain speed and aircraft control. There was no time to request and receive clearance for the altitude change. I believe we must have flown into relatively warm, moist air blowing off the top of a storm to our left, causing marked deterioration in aircraft performance. It appears that the aircraft may have been operating at, or close to, its performance limit altitude for the thrust available and that the encounter with the effects of the thunderstorm resulted in the inability to maintain altitude.
s The aircraft was in level flight at FL350, with some
deviations off course due to weather. At INTXN the pilot unexpectedly announced, “We need to change altitude right now.” Since I did not control the airspace below FL350, I was unable to provide a descent clearance right away. The pilot initiated a descent and I advised the pilot that I was declaring an emergency and to please fill me in on the situation when circumstances permitted…Subsequent discussion with the pilot indicated that the aircraft was unexpectedly unable to maintain altitude… The pilot asked for and received clearance to FL310. Because I was sitting immediately adjacent to the controller [handling] airspace below me, I was able to coordinate the un-cleared descent quickly enough to avoid cascading problems with other aircraft.
ASRS Recently Issued Alerts On…
B757 lavatory fire incident Homebuilt Kitfox rubber tubing failure CL65 uncommanded nose gear retraction Published SID discrepancy at a Mexican airport An international airport’s taxiway signage and marking
A Monthly Safety Bulletin from
The Office of the NASA Aviation Safety Reporting System, P.O. Box 189, Moffett Field, CA 94035-0189 http://asrs.arc.nasa.gov/
October 2002 Report Intake
Air Carrier / Air Taxi Pilots General Aviation Pilots Controllers Cabin/Mechanics/Military/Other TOTAL 1914 741 51 114 2820
飞行翻译公司 www.aviation.cn 本文链接地址：美国ASRS安全公告CALLBACK cb_278.pdf
November 2002
While there have only been scattered flurries of weatherrelated ASRS reports recently, the forecast is for increasing intensity over the next few months. On the brighter side, ASRS Analysts do see a chance for significant clearing of embedded gray cells and foggy
memories provided there is heavy participation in a review of cold weather operations and procedures. A high absorption rate of the towering accumulation of lessons learned could prevent an avalanche of reports at ASRS.
“…We were going to have to find the runway regardless of the weather”
This “chilling” statement reflects the gravity of the situation encountered by an instructor and student in an ice-encumbered Cessna 172. Knowing the limitations of one’s aircraft and having a respect for the forces of nature are two universal lessons learned by the instructor who submitted this report. said, “You probably know this, but I’m getting an altitude alert...” We briefed the approach and knew we were going to have to find the runway regardless of the weather... We saw the approach lights at about 400 feet AGL, almost 500 feet below the localizer approach minimums. We landed without incident (with two inches of ice). The approach and tower controllers were extremely helpful. Causes: We took off into forecast icing conditions… I thought if we could get up high enough (10,000 feet) we could fly over the icing layer… Even a very thin layer of ice on the leading edge and upper wing surfaces can cause a dramatic loss of lift and increase in drag. With two inches of ice, these pilots were lucky to be near an airport.
s The [Cessna 172] began to accumulate light rime ice in
cruise at 10,000 feet… Icing became increasingly heavier until…we were having difficulty maintaining altitude. Departure [said] he needed us to maintain 10,000 feet. I told him we were picking up ice and requested vectors [to the] ILS Runway 35 at XXX… We checked in with the Tower [and we were] cleared to land. Icing was moderate at that point. We had full throttle at 70 KIAS and [we were] descending 400 feet per minute. We were unable to maintain approach minimums, and at one point Tower
Cool Controller Stops a Snowballing Situation
Quick work by a sharp Center Controller not only helped an MD-80 crew out of a bad situation, but also prevented a “chain reaction” of traffic conflicts. This first report gives the Controller’s perspective. And the following report details the pilot’s view of the same incident:
s …Aircraft was in cruise flight at FL350 with airfoil
and engine anti-ice on. [We were] in IMC deviating to the east of thunderstorms. Aircraft speed increased initially from .76 to .78 Mach, then deteriorated to .69 Mach. Performance did not increase so we immediately descended to a lower altitude to regain speed and aircraft control. There was no time to request and receive clearance for the altitude change. I believe we must have flown into relatively warm, moist air blowing off the top of a storm to our left, causing marked deterioration in aircraft performance. It appears that the aircraft may have been operating at, or close to, its performance limit altitude for the thrust available and that the encounter with the effects of the thunderstorm resulted in the inability to maintain altitude.
s The aircraft was in level flight at FL350, with some
deviations off course due to weather. At INTXN the pilot unexpectedly announced, “We need to change altitude right now.” Since I did not control the airspace below FL350, I was unable to provide a descent clearance right away. The pilot initiated a descent and I advised the pilot that I was declaring an emergency and to please fill me in on the situation when circumstances permitted…Subsequent discussion with the pilot indicated that the aircraft was unexpectedly unable to maintain altitude… The pilot asked for and received clearance to FL310. Because I was sitting immediately adjacent to the controller [handling] airspace below me, I was able to coordinate the un-cleared descent quickly enough to avoid cascading problems with other aircraft.
ASRS Recently Issued Alerts On…
B757 lavatory fire incident Homebuilt Kitfox rubber tubing failure CL65 uncommanded nose gear retraction Published SID discrepancy at a Mexican airport An international airport’s taxiway signage and marking
A Monthly Safety Bulletin from
The Office of the NASA Aviation Safety Reporting System, P.O. Box 189, Moffett Field, CA 94035-0189 http://asrs.arc.nasa.gov/
October 2002 Report Intake
Air Carrier / Air Taxi Pilots General Aviation Pilots Controllers Cabin/Mechanics/Military/Other TOTAL 1914 741 51 114 2820
飞行翻译公司 www.aviation.cn 本文链接地址：美国ASRS安全公告CALLBACK cb_278.pdf
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