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Clarence Center Crash

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A DC-8 crashed into a house in Clarence Center lastnight. Sadly everyone on board has been reported to of died. One person in a house that the plane struck was killed, 2 other family members were able to escape the house after the crash. However this is just further proof that no one is in complete control of their lives, even in the safety of ones own home. Clarence Center (Near Buffalo, NY) is very much your ideal American small down. From on scene video and reports on the news, I would guess that this plane went down on High Street, and/or Long Street. The location of the crash site is about 6 miles from the threshold of Runway 23. (in the map the distance to the runway is the blue line, the red line is an estimated path during which the plane descended from its assigned altitude.) View Larger Map Since my prediction of the initial reports in the Hudson River 'Emergency Landing' last month seemed to come out fairly accurate, I will hesitate to guess what happened here based on the little that I know. Keeping in mind these are only the ramblings of my own thoughts on this situation and I have very little information available to me. My guess: The DC-8 plane was on an intercept for Runway 23. Because of how spot on the plane was to the centerline of the ILS (Instrument Landing System) localizer, I would have to conclude that they were locked onto the localizer and the plane was lined up for landing. Therefore I would have to believe that the plane was in a semi-automated ILS landing sequence. 6 miles out is a little far for a plane to hit the glide slope. A glide slope is a part of the ILS system which planes can automatically follow down in order to make a safe descent and landing at the runway. Usually one would hit a glide slope at about 4 to 5 miles from the runway threshold - at this point the plane should never have descended lower then about 3000 ft (or whatever altitude they have been instructed). Weather conditions at the time of the crash were said to be snowy, so the pilots were likely flying in IMC (Instrument meteorological conditions) conditions where they had to rely on their instruments. The temp. is also hovering around 0 degrees C. The most likely cause in this case was a problem with the altitude hold function of the autopilot. It is very possible that the pilots thought they were flying in without a problem, and did not notice that somehow the Altitude hold function had gone off. The plane slowly sank until it struck objects on the ground. With the landing gear already down, there would not of been an alarm for ground proximity. I would not rule out mechanical or complete engine failure, however I find it highly unlikely. If the pilots knew they had a problem and wouldn't make it - they should have gone into full manual flight mode. While it is possible that they did this, I would of likely have been worrying more about maintaining my altitude, then maintaining a perfect ILS approach with Runway 23. The plane seemed too perfectly aligned to the runway to suggest that it was under full human control in this case, just a hunch. This is obviously just my generally self educated observation on this terrible event. Being an engineer at heart, I am always one to try to figure out 'Why?'. My thoughts do go out to the families and loved ones effected by this, and I would like to offer what little support I can towards anyone who needs someone to talk to. UPDATE: People are saying the plane was heading north with its landing gear up? This is seeming very strange indeed. Audio of the event from ATC can be found here. It seems that they were circling the airport and not in fact landing? The recording is suggesting that they were supposed to be heading 310, on a left turn when the last communication was made. This means that the plane was heading north and circling around counter-clockwise. But then, assuming the aircraft was not on a path for a landing, why are they asking other pilots to check the localizer? The aircraft would not of been on the localizer if it wasn't trying to land. The recording also suggests that a US Airways plane noticed variations in the localizer at about 1500ft +/- 1 notch. You will notice that they ask Delta 1998 to disregard the auto-land and watch the localizer manually to watch for variations (they suspected a problem due to the crash, so they must of thought the aircraft was trying to land? but it was heading North-West?). As I said..... very curious, and I don't think we will really know what happens until they start digging into that elusive black box. UPDATE: Looks like it was actually a build up of Rhine Ice which interfered with the normal operation of the plane. These DC-8's have been known to have serious control problems in icy conditions. I did originally consider icing, however at the time I wrote the post the weather did not seem to me - here on the ground 20 miles away - to be bad enough to warrant that. However I suppose having to fly through a snow squall, was enough to build up a lot of ice in a very short amount of time. Well at least I am not psychic... Because that would freak me out. :) UPDATE: Well it is now looking like the Autopilot was engaged when the aircraft crashed. This very likely means that the pilots did not have much time to react. What likely happened was that rhine ice formed on the wings and molded over the flaps. When the flaps were lowered, the rhine ice, having attached itself to the main part of the wing, stayed mostly in place, while the flaps lowered. This would result in reduced lift, and at landing speeds (about 145 kts.) this could induce a stall. Stalling while in autopilot is very bad, as the autopilot will try to auto-correct for the stall, but it generally will not auto-correct enough. In this case manual intervention is usually required - full throttle and full control of the steering yoke. With AP engaged, this was likely not very effective. On a approach such as this they likely also has Auto-Throttle engaged, which controls the engine throttle to maintain speed. While human intervention in the way of moving the throttle SHOULD have an effect without turning off Auto-Pilot, it sometimes doesn't on some planes and with some systems. Had the pilots been able to kick off Auto-Throttle and Auto-Pilot and given the plane more power right away, perhaps this disaster could of been avoided or the death toll at least reduced. It is possible that they did in fact try to lower the nose to recover from the stall, but were unable to recover from the recovery attempt. Either way it is a bad situation to be in, and the chances of getting out spotless are slim. For more coverage, please visit Buffalo News.


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