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#1
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The weather was perfect for flying yesterday morning, sunny, mostly
blue sky with about 12000' ceiling and little wind (unlike the day before when we canceled our flying plan due to 13G24 wind). As usual, we checked weather sites, TAF/weather map etc before heading to the airport. Bad weather is moving in but not until later in the day with 3000' ceiling at 3pm and light rain predicted at midnight or so. Our plan was just to do some local IFR training flights taking turns wearing foggles or acting as the safety pilot. After entering the gate, we glanced at the ramp and saw quite a bit of activities with several vehicles and a small group of people at the north side of runway 24. In closer look, we saw a plane landed off the runway in the grassy area with half of the wing stuck in a fence. We immediately thought that the accident was due to the gusty/windy condition the day before. It turned out that it was due to an engine trouble on take off, luckily the pilot walked away unarm. We saw both the pilot and the owner in the pilot lounge. Both looked quite grave and were busy checking AIG insurance policy on open pilot cause. We have always done a thoroughly preflight inspection and preparation but this incident made us double-checks everything. After plugging in the Reiff heaters and put on the nose mitten, Rick went and chatted with a friend who was preheating his with a propane tank. He also had a new engine and we both felt that preheating was needed even in temp near 40F. The was quite a lot of activities on the ramp and in the pattern in this relatively warm January weather. We went to the mall nearby to pick up some tools at Sears while the engine being heated. In checking the sky after our shopping, I was somewhat concerned of the overcast instead of earlier blue sky but Rick assured me that the ceiling should stay high enough for our practices. We had planned to take off at before noon, but all the activities added up and we did not depart until 1pm. The tanks were more than half full. We thought of topping off but to save time, Rick suggested that instead of flying northeast to Pawling VOR, he could do his practice on the way north to Columbia. We could fuel there and I could fly to Pawling on the swayback for my practice turn. ATIS at taxi time indicated 5000' ceiling with about 2C spread between temp and dew point. While Rick was under the hood, I noticed that both the ceiling and visibility seemed to get worse as we approached 1B1, so I suggested him to cut the practice short and just prepared to land. Columbia AWOS indicated wind at 200, 12 gusting to 18 (in contrast with 6 knots wind at Dutchess) and with only 1C spread between temp and dew point. We quickly fueled up, sumped the fuel, did a walk around inspection, listened to AWOS then took off again. Ceiling had lowered to 3500' and temp and dew point were both at 3C. I turned on the pitot heat and made sure that cowl flap was close and the engine was leaned. After about 15 to 20 minute under the hood, I heard Rick said in a somewhat alarming voice "Change your plan, we are heading back to Dutchess - It has started to rain". Then his raised his voice "Full throttle, full throttle, we have ice on the windshield". Rick immediately put on the defroster while I flipped on all our lights, landing/taxi/nav and double checked that the pitot heat was on, cowl flap close, carb heat off, engine leaned. We wanted the engine to kick off as much heat as possible. At the same time, I was also trying to descend to a lower altitude while keeping the speed just below the yellow arc. Rick wanted me to go down to 2000' both for warmer air and less headwind (we have something like 40' headwind at 3000') but I settled for 2500'thinking altitude was my friend. Rick told me the GPS showed the nearest airport was Kingston at 7nm and asked me whether I wanted to land there. Our encounter with freezing rain was quite brief probably less than a minute, because the windshield ice seemed to start melting where the defroster hit at the pilot's side and there was no evidence of additional ice build up. I had plenty of lift at full throttle, had to pull back the power to stay at 2500' and not getting in the yellow arc. I told Rick that I would continue south to Dutchess toward better weather. KPOU ATIS indicated ceiling of 4000' with 1C spread between temp and dew point. I contacted the tower for landing and also reported our light icing encountered. The tower told us that they would notify flight service. By this time, my side of the windshield was clear enough for VFR. In my vague recollection, I probably relied mostly on the instrument panel trying to keep straight and level, descent at steady rate, following the VOR radial back to KPOU. I have not officially started my instrument training but had done dozens of foggles hours and had just spent the entire week playing with my Christmas present, Elite v.8 with the IFR training manual. The practices really came in handy. In setting up for landing, I tried to stay high and slipped in with only 10-degree flap. Over the fence, I was still pretty high and somewhat fast so I dropped to 20-degree flap and reduced power to near idle to make sure that I would not land long on the 3000 feet runway. The landing was good and I was able to turn left to Alpha taxiway right to our tie-down area. The windshield was totally clear by the time we landed. I immediately got out and check the wings. They were still coated with a clear thin layer of ice which was melting quickly at 38F ground temperature. After my icing report to the tower, there were two planes taking off northbound. On our way out of the airport, we noticed several people standing near the ramp area having their picture taken. Rick stopped and asked whether they planned to go up soon. They nodded with big smiles. The pilot was on the ramp getting the plane ready. Rick told the passengers about the freezing rain/icing and suggested that should not go up. I am not sure whether they comprehend the danger of the situation by the look on their faces. I just hope that they would tell the pilot of our advice. In reviewing the incidence, we realized that we have made several small errors. First, we should leave a wider margin of time for the incoming bad weather. Secondly, we should not have changed our flight plan at the last minute. If we had planned to go north to Columbia, we would have paid closer attention to Albany TAF and weather report. After our flight, I checked my mail and found an urgent winter storm watch and warning for Albany region which remained in effect from noon to 5pm: "WARM MOIST AIR AHEAD OF A WARM FRONT MOVING INTO THE NORTHEAST FROM THE OHIO VALLEY WILL RIDE OVER VERY COLD AIR TRAPPED NEAR THE SURFACE. A MIXTURE OF FREEZING RAIN AND SLEET WILL OVERSPREAD THE REGION FROM WEST TO EAST DURING THE AFTERNOON AS TEMPERATURES GRADUALLY RISE THROUGH THE 20S AND TOWARD THE FREEZING MARK" It I had seen this warning of the temperature inversion, we would not done this flight! Doing my logbook after the flight, I noticed that this flight completed my 400th hour in 4 years. Paul Craig's "The Killing Zone" book identified the dangerous zone being between 50-350hrs. I don't really believe that I am safe being outside of this zone. Piloting is lifelong learning experience. We were just being a bit too complacent with our local flights. This incident was a great wakeup call. Hai Longworth |
#2
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In setting up for landing, I tried to stay high and slipped in with
only 10-degree flap. Over the fence, I was still pretty high and somewhat fast so I dropped to 20-degree flap and reduced power to near idle to make sure that I would not land long on the 3000 feet runway. The landing was good and I was able to turn left to Alpha taxiway right to our tie-down area. Good work, but when iced up, (I hear) it's important not to make big changes in airfoil when landing. The iced up wing is more sensitive to such changes and the disturbed airflow may separate, leading to a low altitude stall. I've never landed with ice, so all this is from what I've heard and read (and seen in FAA videos); others will certainly fill in. It can sure happen quickly. Jose r.a.student trimmed -- Freedom. It seemed like a good idea at the time. for Email, make the obvious change in the address. |
#3
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![]() "Jose" wrote in message m... In setting up for landing, I tried to stay high and slipped in with only 10-degree flap. Over the fence, I was still pretty high and Good work, but when iced up, (I hear) it's important not to make big changes in airfoil when landing. The iced up wing is more sensitive to such changes and the disturbed airflow may separate, leading to a low altitude stall. As I understand there's an evolving body of thought that the real culprit in many of these cases is a tailplane stall rather thna a wing stall. Flap deployment seems to be a decisive factor in precipitating these. The fun part is that if you get into one the recovery procedure is the opposite--nose up--than for a wing stall. This was all in a recent AOPA Pilot issue IIRC. All the more reason to avoid the situation in the first place. -cwk. |
#4
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The weather was perfect for flying yesterday morning, sunny,
Good job, Hai. A little ice goes a long ways toward making you want to be on the ground. The one time we ran into significant icing, we had been trying to flank a cold front that stretched from Illinois to Mexico on a flight from Florida to Iowa. We kept the cold front off our left wing the whole day, as we made our way north, flying just far enough east to stay in the clear. When we got to the "top" of the front, in Illinois, we momentarily penetrated a rain shower that made our windshield go completely opaque just like *that* -- no warning at all. It was quite a shock. Luckily, as we descended toward the nearest airport the ice began sublimating, and we were suddenly on the backside of the front in the clear, cold air. With that, all was well -- but it's an experience we'll never forget. -- Jay Honeck Iowa City, IA Pathfinder N56993 www.AlexisParkInn.com "Your Aviation Destination" |
#5
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Because ice accretion is inverse to the radius of the collecting surface,
you will have about three times as much ice on the leading edge of the horizontal stabilizer compared to the wing's leading edge. Best current guidance is to avoid flap extension if icing is suspected because of the possibility of tailplane stall. Other than that, you done good!!! Bob Gardner wrote in message oups.com... The weather was perfect for flying yesterday morning, sunny, mostly blue sky with about 12000' ceiling and little wind (unlike the day before when we canceled our flying plan due to 13G24 wind). As usual, we checked weather sites, TAF/weather map etc before heading to the airport. Bad weather is moving in but not until later in the day with 3000' ceiling at 3pm and light rain predicted at midnight or so. Our plan was just to do some local IFR training flights taking turns wearing foggles or acting as the safety pilot. After entering the gate, we glanced at the ramp and saw quite a bit of activities with several vehicles and a small group of people at the north side of runway 24. In closer look, we saw a plane landed off the runway in the grassy area with half of the wing stuck in a fence. We immediately thought that the accident was due to the gusty/windy condition the day before. It turned out that it was due to an engine trouble on take off, luckily the pilot walked away unarm. We saw both the pilot and the owner in the pilot lounge. Both looked quite grave and were busy checking AIG insurance policy on open pilot cause. We have always done a thoroughly preflight inspection and preparation but this incident made us double-checks everything. After plugging in the Reiff heaters and put on the nose mitten, Rick went and chatted with a friend who was preheating his with a propane tank. He also had a new engine and we both felt that preheating was needed even in temp near 40F. The was quite a lot of activities on the ramp and in the pattern in this relatively warm January weather. We went to the mall nearby to pick up some tools at Sears while the engine being heated. In checking the sky after our shopping, I was somewhat concerned of the overcast instead of earlier blue sky but Rick assured me that the ceiling should stay high enough for our practices. We had planned to take off at before noon, but all the activities added up and we did not depart until 1pm. The tanks were more than half full. We thought of topping off but to save time, Rick suggested that instead of flying northeast to Pawling VOR, he could do his practice on the way north to Columbia. We could fuel there and I could fly to Pawling on the swayback for my practice turn. ATIS at taxi time indicated 5000' ceiling with about 2C spread between temp and dew point. While Rick was under the hood, I noticed that both the ceiling and visibility seemed to get worse as we approached 1B1, so I suggested him to cut the practice short and just prepared to land. Columbia AWOS indicated wind at 200, 12 gusting to 18 (in contrast with 6 knots wind at Dutchess) and with only 1C spread between temp and dew point. We quickly fueled up, sumped the fuel, did a walk around inspection, listened to AWOS then took off again. Ceiling had lowered to 3500' and temp and dew point were both at 3C. I turned on the pitot heat and made sure that cowl flap was close and the engine was leaned. After about 15 to 20 minute under the hood, I heard Rick said in a somewhat alarming voice "Change your plan, we are heading back to Dutchess - It has started to rain". Then his raised his voice "Full throttle, full throttle, we have ice on the windshield". Rick immediately put on the defroster while I flipped on all our lights, landing/taxi/nav and double checked that the pitot heat was on, cowl flap close, carb heat off, engine leaned. We wanted the engine to kick off as much heat as possible. At the same time, I was also trying to descend to a lower altitude while keeping the speed just below the yellow arc. Rick wanted me to go down to 2000' both for warmer air and less headwind (we have something like 40' headwind at 3000') but I settled for 2500'thinking altitude was my friend. Rick told me the GPS showed the nearest airport was Kingston at 7nm and asked me whether I wanted to land there. Our encounter with freezing rain was quite brief probably less than a minute, because the windshield ice seemed to start melting where the defroster hit at the pilot's side and there was no evidence of additional ice build up. I had plenty of lift at full throttle, had to pull back the power to stay at 2500' and not getting in the yellow arc. I told Rick that I would continue south to Dutchess toward better weather. KPOU ATIS indicated ceiling of 4000' with 1C spread between temp and dew point. I contacted the tower for landing and also reported our light icing encountered. The tower told us that they would notify flight service. By this time, my side of the windshield was clear enough for VFR. In my vague recollection, I probably relied mostly on the instrument panel trying to keep straight and level, descent at steady rate, following the VOR radial back to KPOU. I have not officially started my instrument training but had done dozens of foggles hours and had just spent the entire week playing with my Christmas present, Elite v.8 with the IFR training manual. The practices really came in handy. In setting up for landing, I tried to stay high and slipped in with only 10-degree flap. Over the fence, I was still pretty high and somewhat fast so I dropped to 20-degree flap and reduced power to near idle to make sure that I would not land long on the 3000 feet runway. The landing was good and I was able to turn left to Alpha taxiway right to our tie-down area. The windshield was totally clear by the time we landed. I immediately got out and check the wings. They were still coated with a clear thin layer of ice which was melting quickly at 38F ground temperature. After my icing report to the tower, there were two planes taking off northbound. On our way out of the airport, we noticed several people standing near the ramp area having their picture taken. Rick stopped and asked whether they planned to go up soon. They nodded with big smiles. The pilot was on the ramp getting the plane ready. Rick told the passengers about the freezing rain/icing and suggested that should not go up. I am not sure whether they comprehend the danger of the situation by the look on their faces. I just hope that they would tell the pilot of our advice. In reviewing the incidence, we realized that we have made several small errors. First, we should leave a wider margin of time for the incoming bad weather. Secondly, we should not have changed our flight plan at the last minute. If we had planned to go north to Columbia, we would have paid closer attention to Albany TAF and weather report. After our flight, I checked my mail and found an urgent winter storm watch and warning for Albany region which remained in effect from noon to 5pm: "WARM MOIST AIR AHEAD OF A WARM FRONT MOVING INTO THE NORTHEAST FROM THE OHIO VALLEY WILL RIDE OVER VERY COLD AIR TRAPPED NEAR THE SURFACE. A MIXTURE OF FREEZING RAIN AND SLEET WILL OVERSPREAD THE REGION FROM WEST TO EAST DURING THE AFTERNOON AS TEMPERATURES GRADUALLY RISE THROUGH THE 20S AND TOWARD THE FREEZING MARK" It I had seen this warning of the temperature inversion, we would not done this flight! Doing my logbook after the flight, I noticed that this flight completed my 400th hour in 4 years. Paul Craig's "The Killing Zone" book identified the dangerous zone being between 50-350hrs. I don't really believe that I am safe being outside of this zone. Piloting is lifelong learning experience. We were just being a bit too complacent with our local flights. This incident was a great wakeup call. Hai Longworth |
#6
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The tail plane stall that all keep talking about, isn't it caused by
icing over a stablizer that is at or just below the plane of the wing? Then when the flaps are deployed, the air is disturbed sufficiently that the tail stalls? Therefore, if flying a T tail (or similar), deployment of flaps should not affect the tail. Is this correct? I'm asking because of flying a Piper wherein the wing is actually below the stabliator. Deployment of 15 degrees of flaps should not sufficiently disturb the airflow to cause the tail plane stall in this case. Is this correct? Later, Steve.T PP ASEL/Instrument ps. I'm almost at that 350hr mark some one else mentioned. T-storms, fog and ice conditions are automatic no-go situations for me. Too much at stake. |
#7
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It is not just the flap deployment altering airflow over the stabilizer
that causes a tail plane stall - though that is a major problem for many airplanes - but it is also the slowing up with flap deployment which forces the horizontal stabilizer to fly at a higher angle of attack (downward attack, of course)... So T-tails need to be flown exactly the same way as straight tails... If the ship has a load of ice (weight) forcing the airfoils to fly at a higher angle of attack to begin with and the stab has ice distorting it's airfoil, then increasing the angle of attack even further by slowing up will/can be the final straw leading to an accelerated tail plane stall followed instantly by the nose pitching downward sharply..... If you are iced up, forget the flaps and keep the speed up until the wheels are just above the runway... It is far better to deal with a possible low speed over run off the end of the runway, than a pitch over at a few hundred feet of altitude where death is certain... Thunder bumpers, fog, and icing, are ABSOLUTE no-go situations for me... Remember this old saw, because it is absolutely true: There are old pilots... There are bold pilots... But there are no old-bold pilots... Denny |
#8
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Bob,
Thank you very much for your tailplane stall explanation. We attended a Wing Safety Seminar last November on Winter Operations where it was mentioned but only in term of symptoms and recovery process. I did not realize that there would be more chance of a tailplane stall than wing stall due to heavier ice accumulation. Before landing, I had discussed with my husband, Rick on whether I should have landed with no flaps or with 10 degree flap. Since the standard Cardinal takeoff procedure calls for 10 degree flap, we thought it would provide more lift. We did not think of the possiblity of tailplane stall. Although I had practiced landings with different flap configurations every few months, I generally dislike the noflap approach due to extremely nose high position. I hate not being able to see a darn thing ahead while landing. The practices did come in handy late last fall in our long cross country trip from New York to northern Minnesota. Within an hour of flying, we had complete electrical failuires due to a bad crimp job on one ot the alternator wires. We have owned our plane for about 1 1/2 years and put over 200hrs on it. It was our luck that we landed at Seaman airport and the folks at O&N aviation (the home of the Silver Eagle) were open on Saturday. They found the problem right away and get us going within few hours. The owner did not write up a bill and told us just to give a tip to his mechanics. Fantastic folks!. (Note to Jay: In our short flying career, this was our first 'emergency' situation, the icing incidence was the second. Luckily ;-) , I was the PIC in both cases and Rick mainly offered assistance and did not insist on taking over. Just wonder how you and Mary handle your flying responsibilities?). On an aside note, for our instrument training, I bought at least half a dozen books on the subject. Rick was ahead of me so he had reviewed all of them. His main text book was your book, "The Complete Advanced Pilot". He got 98 on his written and recommend me to start right away with your book using others as supplemental readings. We have also made good use of your "Say Again, Please" book. Thank you so much for imparting your years of aviation skills, experiendce, wisdom and insight to many next generations of pilots. Best regards, Hai Longworth |
#9
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Denny,
Is is our modus operandi too. As I mentioned in my reply to Bob Gardner, we attended the Wing Safety Seminar on Winter Operation last November. Our thought was that we would never let it happen to us ! Little did we know that we would encounter icing in a short local excursion on a day which we thought was perfect for flying. BTW, the urgent weather warning which I received was through my-cast, a 'regular' and not aviation weather servcie. The TAF for Albany area mentioned drizzle rain but much later in the day. POU TAFdid not indicate any precipitation, 1B1 is between the two airports. The very short duration of the freezing rain indicated that it could be very local, just under a rain cloud. We might not have encountered it if we were few miles East or West. |
#10
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![]() " writes: [...] Before landing, I had discussed with my husband, Rick on whether I should have landed with no flaps or with 10 degree flap. [...] I generally dislike the noflap approach due to extremely nose high position. I hate not being able to see a darn thing ahead while landing. [...] Next time this happens, consider not only landing flapless, but touching down at well above normal stall airspeed, basically doing an airliner (or floatplane still-water) style flying-to-the-ground landing. The pitch angle won't be so high, and you won't be at the mercy of the possibly nastier stall characteristics with ice on the wings. You would need a longer runway. - FChE |
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