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Taiwan Jet Explodes Into Fire in Japan

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Is China Airlines the one with one of the lower safety records?RhettAMD 3700+ (@2585 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2gb Corsair XMS 3-3-3-8 (1T), WD 150 gig 10000rpm Raptor, WD 250gig 7200rpm SATA2, Seagate 120gb 5400 rpm external HD, CoolerMaster Praetorian

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>Is China Airlines the one with one of the lower safety>records?>>Rhett>>AMD 3700+ (@2585 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS>A8N-E, PC Power 510 SLI, 2gb Corsair XMS 3-3-3-8 (1T), WD 150>gig 10000rpm Raptor, WD 250gig 7200rpm SATA2, Seagate 120gb>5400 rpm external HD, CoolerMaster PraetorianYep, that's the one but as best as I recall offhand it has usually been pilot error rather than mechanical failures, so at this very early stage and given the nature of the incident, my hunch would be that it was equipment failure with possably no fault on the part of the airline.Best and Warm RegardsAdrian Wainer

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Fire resulting from fuel leak on left engine plus 4 main gear tires = "four explosions". Video indicates pretty clearly that the "explosions" were the tires blowing out. It'll be interesting to hear how the fuel leak occured. Glad everyone got out okay.

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great news is that no one was killed.planes and other personal property are never more important than lives.the cause will be interesting ... human error as caused by poor maintenance practice, mechanical failure, something in design, other?--

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Glad the crew did not hesitate to initiate evac. According to the Japan Air Ministry official in the video, once the leak was reported the plan was evacuated within 90 seconds. As you can see in the video, shortly thereafter the large explosion occurred.bt

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This is an accident involving a 737 at Manchester England, amongst the many differences between the China Airlines accident and the Manchester tragedy would be the many changes in design and equipments the 737 has gone through since the Manchester fire, but I thought it would be usefull never the less to see to put the accident report for the Manchester tragedy in to this thread, to see if there might be any similarities between the two events.http://www.aaib.gov.uk/sites/aaib/cms_reso..._pdf_502609.pdfBest and Warm RegardsAdrian Wainer

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The plane lands 'normally' with possible blown tires.Taxi's to the stand - then ground crew report a fuel leak - and the fuel catches fire.Goes to show my old saying is correct - "The safest seat on an airplane in next to an exit"Since the majority of evacuation tests fail the 2 minute mark - these folks were motivated to get off this plane.Blown tires on landing or takeoff almost always cause damage to the underside of the wings. Punctures of the wing and fuel tanks are not uncommon.That was the basic cause of the Concorde crash.Again, lucky and motivated people.

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And you have to ask, what caused the tires to blow out in the first place? Was it debris on the runway, like the Concorde crash? Was debris kicked up into the fuselage or wing? You do not necessarily have to sit next to an exit to be in a "safer" seat. Only a handfull of passengers can sit there, but one should be aware of where those exits are and how many rows you are from them. Do whatever you have to do to remember the number of rows you have to go before you get to the exit. In a real emergency there will not be enough time to sit back and look for exits.John M

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>what caused the tires to blow out in the first place?i would say the cause of the tires blow as the heat caused by the fire ...--

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Sad to see but it is believed that the China Airlines didn't do a scheduled check on the bolt out of one of the slats and that punctured the fuel line. Boeing issued a maintanence circular in 2005 or 2006 about this problem and the hazards it can pose.

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The loose bolt is just another little problem that seems to be adding to continuing list of defects that are showing up in the venerable Boeing 737 series.There have been problems with the engine housings being out of round and causing turbine blade failure. I think that was a cause of the engine failure in Manchester, England incident. The most deadly failure I can recall is the rudder reversal occurrences that caused at least two fatal air crashes. I was living in Colorado Springs at the time the United 737 crash occurred and I remember it was an extremely windy day, cross winds gusted to 50 miles an hour at KCOS. After years of investigation, it turned out that the hydraulic control unit that operated the rudder was susceptible to thermal shock and one side of the dual control unit would seize when going from extreme cold to warmer temperatures, causing the rudder to go full hard over when the pilot applied sudden rudder inputs, which would be the case in a severe crosswind landing.Pilots could recover from this occurrence at higher speeds and altitudes (that's how the investigators figured out the problem when it happened to two other airliners that the pilots were able to recover from the roll). But at approach speeds and altitudes, they could get into what is called a 'crossover stall' whereas one wing would stall before the other at low speeds when a sudden yaw occurred, especially dangerous during crosswind landings. When the rudder slammed over on the United flight, the aircraft violently rolled over when the right wing stalled and the pilots had no chance to recover from the resulting roll.As best as I can remember, I think Boeing had to issue new higher landing speeds to all 737 pilots while the cause was being sorted out.Kim

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kim:the number of ADs issued for aircraft of all makes is rather amazing. i worked for in seattle alaska airlines records in the late 1980s. i filed and retrieved information on the MD80 fleet. i remember, as i was 'new' to this type of work at the time, thinking, "all these aircraft are broken."take a look yourself on ADs issued for modern 'large' jet transport aircraft -http://www.airweb.faa.gov/Regulatory_and_G...me?OpenFrameSetnote all the names in the last 60 days - airbus, boeing, Bombardier, EMBRAER, General Electric, MD, Pratt & Whitney, etc.--

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Scobie,Yeah, I bet if the average airline passenger could read all the AD's, they probably wouldn't even get on the plane!However, this particular 737 fault was quite frightening since not only was it random, but unfortunately deadly. Investigators couldn't pinpoint the problem for YEARS, all the while allowing 737's to keep flying. Boeing and the Airline Pilots Association placed the blame at on other during this whole investigation.If you want to read about the United and USAir 737 crashes concerning this problem, you should find the book by Bill Adair called: The Mystery of Flight 427. It's quite interesting.Kim

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For years I have worked in the computer industry, specifically around infrastructure.You would not believe the amount of patches (AD's) that are issued for the network and hardware that supports it. I know planes and networks ain't the same, but the reality is, in this context, they're pretty close.My 2 cents,bt

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the 737 rudder issue is a good example of how many things need to be in place for a 'fault' to occur. as also stated here, much like computers and finding the cause of a network/software crash ... may look easy at first glance; but hard to find the exact sequence to identify and then create a fix.--

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>The loose bolt is just another little problem that seems to>be adding to continuing list of defects that are showing up in>the venerable Boeing 737 series.>It was never a defect but a design that when not replaced correctly would not work. That is what happened in this case. The mechanics forgot to put the washer back in and the bolt fell out simple as that.But at approach speeds and altitudes, they could get into what is called a>'crossover stall' whereas one wing would stall before the>other at low speeds when a sudden yaw occurred, especially>dangerous during crosswind landings. When the rudder slammed>over on the United flight, the aircraft violently rolled over>when the right wing stalled and the pilots had no chance to>recover from the resulting roll.This is known as a cross-control stall

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>>Pilots could recover from this occurrence at higher speeds and>altitudes (that's how the investigators figured out the>problem when it happened to two other airliners that the>pilots were able to recover from the roll). But at approach>speeds and altitudes, they could get into what is called a>'crossover stall' whereas one wing would stall before the>other at low speeds when a sudden yaw occurred, especially>dangerous during crosswind landings. When the rudder slammed>over on the United flight, the aircraft violently rolled over>when the right wing stalled and the pilots had no chance to>recover from the resulting roll.>>As best as I can remember, I think Boeing had to issue new>higher landing speeds to all 737 pilots while the cause was>being sorted out.>>Kim You are confused. There is no such thing as "crossover stall." There is such a thing as "crossover speed." This was something discussed with regard to the USAir and United 737 crashes and A300 crash. If you were above crossover speed, you had enough aileron authority to overcome any uncommanded rudder hardovers, while below that speed, you did not.If the loose bolt was because CAL maintenance did not comply with a maintenance bulletin for a known problem, then you can't blame Boeing for this one. Every single airplane out there has its problems. The longer a plane has been in service and the greater their numbers, the more which will come to light. Once a problem comes to light, one of three things will happen. The problem can be redesigned by the manufacturer, a maintenance procedure can be instituted for it, or a cockpit procedure can be added for it. All of which are valid for making the plane safe. If a required maintenance procedure was not followed, then there is nothing either the manufacturer nor pilots could have done to prevent anything.

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You're right, I meant 'crossover speed stall', my mistake when I was interrupted writing the post. The 'one wing stall' is a more dangerous quirk of swept wing aircraft when a quick or excessive yaw occurs during slow speed flight. The wing that moves backwards during the yaw will lose far more lift because of it's angle relative to the airflow. This problem is not as severe on aircraft with wings positioned ninety degrees to the body of the aircraft, although it can still happen.The resulting stall will roll the aircraft violently to the stalled wing side, and if there is insufficent airspeed and altitude, recovery is not possible.When I lived in Colorado Springs, I had to connect between Denver and KCOS many times. Pilots used to do a very steep (more than 30 degrees) and short final turn onto runway 35L. I assume that they were in a hurry to land, but that practice seemed to stop after the United accident. Nice gentle 25 degree turns and less views of the ground through the windows while sitting on the opposite side of aircraft.These one wing stalls don't seem to be modeled very well with the jetliners in FS. The aircraft don't roll enough that you can't recover.Kim

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There is no such thing as a "crossover speed stall" either. What you are describing is a cross-control stall. The only term in aviation that includes the word "crossover" is "crossover speed." Crossover speed was a factor in the crashes because at the time of the uncommanded rudder deflection, they were below crossover speed, which meant that they did not have enough aileron roll authority to overcome the rudder input. The Tradewinds 737 survived the rudder hardover because they were flying fast enough above crossover speed that they had enough aileron authority to overcome the rudder hardover. Those planes did not crash because of cross control stalls in the sense in which you are describing it. None of them were turning onto final at the time. They were just minding their own business in straight and level flight several thousand feet up and miles from the airport when they crashed. The rudder malfunction caused the rudder to deflect in the opposite direction of the pilot's command. Once the planes were already deep in their death spirals, you can perhaps say that they were in a potential cross control stall situation because they had a continuous rudder deflection with opposite aileron and stick back. But that is secondary to the actual situation, which is the plane entered an uncontrolled roll because of an uncommanded rudder deflection at a point where their airspeed was insufficient for the ailerons to counteract the rudder malfunction. Those crashes had nothing to do with whether people are turning final more gently or not. Any differences you think you noticed between how a plane was flown before or after those accidents as a passenger or observer are imagined or coincidental at best.

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Let me do some research on where I got the terminalogy. I'll post back on what I find. 'Crossover speed' is a known term, but I read a descriptive term somewhere that referred to the particular type of stall which occurs when the aircraft is near that speed and a sudden yaw occurs, stalling only one wing and causing a roll, so I'll look for where that was referenced.As for the steepness of a percived bank angle, one time on approach to KCOS in a DC-10, the turn on final was definately beyond normal proceedures. It was so noticeable that other passengers even commented on it and g-forces were definitely felt. Due to the common occurrances of rotor winds off of the front range, there was mention in the news of proceedure changes for final approach turns into KCOS until the cause of the United crash could be determined.Kim

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http://www.apstraining.com/article3_fci_training_dec02.htmThis looks like the article you may have read. They use the words "crossover speed" and "stall" in close proximity, but read closely because nowhere is he using the phrase "crossover speed stall." The discussion is about the result of the relation of the crossover speed and the accelerated stall they ended up in. A plane will stall at any speed, that is why you have normal stalls, power off stalls, power on stalls, accelerated stalls, etc. but nowhere is the word "speed" attached. Speed has nothing to do with stalling an airplane.

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O.K. readers. I've finally done my due diligence and read through Bill Adair's 2002 book, The Mystery of Flight 427, to find the correct information. The term I was one I hadn't heard before, so I guess my memory failed me in my last posts, my apologies. Passages from Bill's book are in quotes.The term is called 'crossover point', defined by the author Bill Adair as: "The critical airspeed at which a full swing by the 737's rudder cannot be counteracted by the ailerons. When a plane has a rudder hardover while flying slower than the crossover point, the pilot must speed up to regain control."He also referred to the crossover point as; "the precarious moment in flight when the plane is at the mercy of the rudder. It was an aerodynamic quirk that Cox called the 'hole in the flight envelope'". John Cox was a USAir pilot and incident investigator for the airline pilot's union at the time of the USAir crash. Essentially, this is the speed at which the ailerons cannot counteract a sudden movement or a full hardover of the rudder. If the aircraft is going slower than the crossover point, a roll occurs that will result in loss of control unless there is sufficient altitude for recovery and the pilots are trained in the proper procedures for regaining attitude and speed. This quirk can also be far more unforgiving in swept wing aircraft.When the 737 aircraft was certified in 1967, the crossover point was not considered to be a problem. Boeing stated that if there was ever a rudder control valve failure, the ailerons were more than capable of countering the roll. This was found out years later to be incorrect. While flight-testing a 737 in 1995 after the USAir crash, John Cox and the other investigative pilots and engineers used the speed and flap settings that the USAir pilots were using just prior to the crash. After Cox got set up at flaps 1 and 190 knots, he began to apply a rudder input until he had full deflection. He maintained this steady-heading sideslip and began to reduce speed. At 187 knots, he found that he had to push forward on the yoke to lower the nose and regain airspeed in order to recover and aileron use alone was insufficient to counter the roll. He and the other pilots came to the conclusion that the crossover point was too high, not what they were expecting from the 737. It was also the exact approach speed that USAir Flight 427 was traveling at when it flipped over. The USAir pilots "ran out of roll authority". At normal 737 approach speeds, this could be a very precarious position for pilots to be in.The other contributing factor was the design of the 737's hydraulic rudder control unit, called the "dual concentric servo valve". The valve had two pistons, one inside the other. If one piston ever seized during flight, the unit was supposed to return to a neutral position. However, it was found during testing that thermal shock could cause one piston to seize, e.g. a cold valve getting a dose of hot hydraulic fluid. Hydraulic overpressure would then slam the other piston to full extension. Not only did full rudder deflection occur but it would do it in the opposite direction from the rudder pedal position. The confused pilots would be pushing hard on one pedal while the rudder was actually in the opposite position!In the USAir incident, wake turbulence from an earlier aircraft and in the Colorado Springs incident, severe rotor crosswinds off of the Front Range Mountains were determined to be the initiating causes in both fatal events. Boeing claims that all 737's will be refitted with newer two valve systems by 2007 (an improved valve was installed in the meantime). Pilots have now been alerted to the crossover point and are trained in the proper recovery techniques in case of anomalous rudder movements.Sorry for the long post but I hope all those interested in accident investigation give this book a read. It gives a very interesting view of an NTSB investigation.Kim

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