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Post mortem on an IEC connector
"Meat Plow" wrote in message ... On Tue, 2 Jun 2009 10:49:57 +0100, "Arfa Daily" wrote: Seems that today, an Air France Airbus A330 en route from Rio to Paris with 238 people on board, has gone down without warning over the Atlantic. Hard to see what the pilot might have done wrong with the thing at 38000 ft in the cruise ... Apparently, it disappeared off African trans-atlantic ATC radar, at around 3am, our time. This is not instilling a lot of confidence in me, regarding flying on one of these things in October, instead of my usual Boeing ... :-| Electrical and turbulence problems reported. Aircraft was sending distress signals so it may have made a decent ditch. Air France's last air disaster was the Concorde in 2000. I've flown the 320-100 several times and the Mulhouse crash never entered my mind. We actually had a 5 hour delay one time after a hydraulic pump failed on the ground and had to be replaced. I wouldn't worry about the 330 considering the number of those things in the air at any given time and it's wonderful track record. Yeah, I know what you're saying. It just bothers me a little that on say a 747, the driver has got a triple redundancy control system which hydraulically links his yoke and pedals directly to the control surfaces, and a robot driver that can be thoroughly switched off, such that in an unusual set of circumstances, a quick-thinking and experienced guy sitting behind those controls, might be able to recover a potentially catastrophic situation by thinking outside the box, and doing something which maybe puts the airframe outside of the 'safe' envelope. From what I can understand of the FBW systems, they are never going to allow you to do this, and in the event of a total electrical systems collapse, your little joystick, and the computer(s) that it's connected to, are not going to be of any use to control the aircraft, anyway. My pilot friend rang me yesterday when all this was going down (honestly, no pun intended). He felt that there had to be more to it than just flying into a storm. He says that in general, if lightning hits an aluminium-bodied plane, it tends to pass around the outside, and re-discharge and carry on its way from the opposite side or wherever. He questioned whether the same would happen on a carbon composite bodied plane, as the A330 apparently is, or whether the higher electrical resistance of such a material, would cause the lightning to 'stick around' as it were, and just fry the internal systems, or even heat the material to the point where it just exploded. He reckons that unless there was an absolutely catastrophic failure of the airframe, a distress signal should have been able to be broadcast almost all the way down, as the last voice transmitter is battery powered to ensure that it can still operate, even in the event of a catastrophic electrical or systems failure. Sobering thoughts ... Arfa Nah the Airbus is Aluminum skin sandwiched with carbon fiber inside.The same 'Faraday" effect applies. If I were to fly the 747 I would surely think of the design flaws that caused the fuel tank to explode on Flight 800. Or the one where the rear section cracked and lost pressure on the dome that seals the rear end of the fuselage. No I wouldn't enjoy flying through an electrical storm in any aircraft but I wouldn't be any more worried in an Airbus. Military aircraft with complete fly by wire don't seem to have problems with electrical discharge on the skin. I can imagine say an F/A 18E flying at mach two encountering some extreme static electricity from the friction of air and water molecules. One can only wonder how many Joules develope on the aircraft's skin. Hmmm. I wonder if a couple of sheets of Bacofoil glued on a vaguely conductive piece of plastic-y material, is actually as good a dissipative or deflective surface for lightning, as a 5mm thick fully metal skin ? I have watched the programmes on both of the crashes that you quote, and I agree that they give a (small) degree of cause for concern, but at least they were both pinned down to exactly what caused them, and I would think that suitable protective measures were put in place to prevent a recurrence. Considering the size of the 747, and the number of years that the basic design has been flying now, I think that it has proven to be a fantastically reliable and safe aircraft. Still, apparently, they have now located some wreckage 400 miles out into the Atlantic, so I guess that they have around 28 days left to locate and recover the CVR and FDR boxes, which apparently are likely to be lying in around 13000 feet of water. Seems like the batteries for the pingers are good for about 30 days, and the transmitter is just about man enough to get a signal through 15000 feet of salt water. I guess that if they can recover them and they continued to function for any time after the initial 'event', then we could know quite quickly what the primary cause of it going down was. Arfa |
Post mortem on an IEC connector
N_Cook wrote:
Ron wrote in message ... N_Cook wrote: -- -- N_Cook wrote in message ... Ron wrote in message ... Arfa Daily wrote: "Eeyore" wrote in message ... Arfa Daily wrote: "Meat Plow" wrote On Wed, 27 May 2009 14:10:55 +0100, "Arfa Daily" wrote: "Adrian Tuddenham" wrote Arfa Daily wrote: "Adrian Tuddenham" wrote Eeyore wrote: I`ve been following the chat on Pprune, but it would appear that the server is now overloaded. It seems like it flew into bad weather, there was some kind of elecrical problem reported shortly before all contact was lost. How do you make a Faraday cage out of GRP? without making it as heavy as the metal you are replacing. -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ According to my paper , no Faraday cages these days. Apparently "static wicks", wires buried on the edges of wings and tail is supposed to do the job that an overall shell of aluminium used to do. It`s some kind of light wire mesh laminated into the CF. General chat on the PP forum would suggest that composite based airframes seem to attract lightning more than aluminium clad ones do. Ron(UK) Suely its not whether they attract, that is how lightning conductors work. But how easiily the current passes around the frame and out the other side, with as little ohmic heating on the way, to continue its cloud to cloud path. I`m just repeating what professional pilots have to say on the matter. Ron |
Post mortem on an IEC connector
Arfa Daily wrote:
"Ron" wrote in message ... Arfa Daily wrote: Seems that today, an Air France Airbus A330 en route from Rio to Paris with 238 people on board, has gone down without warning over the Atlantic. Hard to see what the pilot might have done wrong with the thing at 38000 ft in the cruise ... Apparently, it disappeared off African trans-atlantic ATC radar, at around 3am, our time. This is not instilling a lot of confidence in me, regarding flying on one of these things in October, instead of my usual Boeing ... :-| Electrical and turbulence problems reported. Aircraft was sending distress signals so it may have made a decent ditch. Air France's last air disaster was the Concorde in 2000. I've flown the 320-100 several times and the Mulhouse crash never entered my mind. We actually had a 5 hour delay one time after a hydraulic pump failed on the ground and had to be replaced. I wouldn't worry about the 330 considering the number of those things in the air at any given time and it's wonderful track record. Yeah, I know what you're saying. It just bothers me a little that on say a 747, the driver has got a triple redundancy control system which hydraulically links his yoke and pedals directly to the control surfaces, and a robot driver that can be thoroughly switched off, such that in an unusual set of circumstances, a quick-thinking and experienced guy sitting behind those controls, might be able to recover a potentially catastrophic situation by thinking outside the box, and doing something which maybe puts the airframe outside of the 'safe' envelope. From what I can understand of the FBW systems, they are never going to allow you to do this, and in the event of a total electrical systems collapse, your little joystick, and the computer(s) that it's connected to, are not going to be of any use to control the aircraft, anyway. My pilot friend rang me yesterday when all this was going down (honestly, no pun intended). He felt that there had to be more to it than just flying into a storm. He says that in general, if lightning hits an aluminium-bodied plane, it tends to pass around the outside, and re-discharge and carry on its way from the opposite side or wherever. He questioned whether the same would happen on a carbon composite bodied plane, as the A330 apparently is, or whether the higher electrical resistance of such a material, would cause the lightning to 'stick around' as it were, and just fry the internal systems, or even heat the material to the point where it just exploded. He reckons that unless there was an absolutely catastrophic failure of the airframe, a distress signal should have been able to be broadcast almost all the way down, as the last voice transmitter is battery powered to ensure that it can still operate, even in the event of a catastrophic electrical or systems failure. Sobering thoughts ... From reading the boards, it appears that, rather than flowing arond the outside of the aircraft, lightning is more inclined to punch holes right through composite skins, thereby getting into the metalwork and wiring. Ron(UK) So, perhaps not the best choice of material to make a long haul aircraft from, given that it is going to fly to areas of the world where thunderstorms are prevalent, and at cruising altitudes where it is well up amongst the crap, as it were. I have actually flown in and out of both Orlando and Las Vegas, with thunderstorms in the area, without giving them a second thought. But then that was in a nice 747 aluminium cigar tube ... If it is true that CC skins are not good in areas of electrical storm activity, I'm sure pilots regularly flying such planes, must be aware of this, so if the weather radar on this flight showed that he was heading into bad air and storms, I wonder why he didn't go around it, or see if it was possible to climb above the worst of it ? I understand that thunderheads can extend above the maximum ceiling of airliners, but I would have thought that there might have been a 'way through' between cells ? Fuel constraints maybe ? Looking on a map, the path from Rio to Paris looks awfully long for a plane of this size. There`s a lot of stuff, some useful some 'not so' on the PPrune boards about this accident. Many of the posts are from people who fly these birds everyday for a living, it`s a good read. BTW, is that Ron ex LVA ? If so, you haven't by any chance got a schematic set for a Warwick Sweet 25.1, have you ? Or anyone else reading this ? Warwick have refused to even acknowledge requests for assistance, let alone supply info. Well LVA is still alive and well, I just don't do many repairs any more, I`m concentrating more on live sound production. Sorry Arfa I don`t have a diag for that amp. Ron(UK) |
Post mortem on an IEC connector
"Ron" wrote in message ... Arfa Daily wrote: "Ron" wrote in message ... Arfa Daily wrote: Seems that today, an Air France Airbus A330 en route from Rio to Paris with 238 people on board, has gone down without warning over the Atlantic. Hard to see what the pilot might have done wrong with the thing at 38000 ft in the cruise ... Apparently, it disappeared off African trans-atlantic ATC radar, at around 3am, our time. This is not instilling a lot of confidence in me, regarding flying on one of these things in October, instead of my usual Boeing ... :-| Electrical and turbulence problems reported. Aircraft was sending distress signals so it may have made a decent ditch. Air France's last air disaster was the Concorde in 2000. I've flown the 320-100 several times and the Mulhouse crash never entered my mind. We actually had a 5 hour delay one time after a hydraulic pump failed on the ground and had to be replaced. I wouldn't worry about the 330 considering the number of those things in the air at any given time and it's wonderful track record. Yeah, I know what you're saying. It just bothers me a little that on say a 747, the driver has got a triple redundancy control system which hydraulically links his yoke and pedals directly to the control surfaces, and a robot driver that can be thoroughly switched off, such that in an unusual set of circumstances, a quick-thinking and experienced guy sitting behind those controls, might be able to recover a potentially catastrophic situation by thinking outside the box, and doing something which maybe puts the airframe outside of the 'safe' envelope. From what I can understand of the FBW systems, they are never going to allow you to do this, and in the event of a total electrical systems collapse, your little joystick, and the computer(s) that it's connected to, are not going to be of any use to control the aircraft, anyway. My pilot friend rang me yesterday when all this was going down (honestly, no pun intended). He felt that there had to be more to it than just flying into a storm. He says that in general, if lightning hits an aluminium-bodied plane, it tends to pass around the outside, and re-discharge and carry on its way from the opposite side or wherever. He questioned whether the same would happen on a carbon composite bodied plane, as the A330 apparently is, or whether the higher electrical resistance of such a material, would cause the lightning to 'stick around' as it were, and just fry the internal systems, or even heat the material to the point where it just exploded. He reckons that unless there was an absolutely catastrophic failure of the airframe, a distress signal should have been able to be broadcast almost all the way down, as the last voice transmitter is battery powered to ensure that it can still operate, even in the event of a catastrophic electrical or systems failure. Sobering thoughts ... From reading the boards, it appears that, rather than flowing arond the outside of the aircraft, lightning is more inclined to punch holes right through composite skins, thereby getting into the metalwork and wiring. Ron(UK) So, perhaps not the best choice of material to make a long haul aircraft from, given that it is going to fly to areas of the world where thunderstorms are prevalent, and at cruising altitudes where it is well up amongst the crap, as it were. I have actually flown in and out of both Orlando and Las Vegas, with thunderstorms in the area, without giving them a second thought. But then that was in a nice 747 aluminium cigar tube ... If it is true that CC skins are not good in areas of electrical storm activity, I'm sure pilots regularly flying such planes, must be aware of this, so if the weather radar on this flight showed that he was heading into bad air and storms, I wonder why he didn't go around it, or see if it was possible to climb above the worst of it ? I understand that thunderheads can extend above the maximum ceiling of airliners, but I would have thought that there might have been a 'way through' between cells ? Fuel constraints maybe ? Looking on a map, the path from Rio to Paris looks awfully long for a plane of this size. There`s a lot of stuff, some useful some 'not so' on the PPrune boards about this accident. Many of the posts are from people who fly these birds everyday for a living, it`s a good read. BTW, is that Ron ex LVA ? If so, you haven't by any chance got a schematic set for a Warwick Sweet 25.1, have you ? Or anyone else reading this ? Warwick have refused to even acknowledge requests for assistance, let alone supply info. Well LVA is still alive and well, I just don't do many repairs any more, I`m concentrating more on live sound production. Sorry Arfa I don`t have a diag for that amp. Ron(UK) No sweat. I've found the problem now. Some moron had pinched a wire to the fans under a board mounting pillar when reassembling after some previous repair. It had nicked the insulation, resulting in an intermittent short to the metal pillar. Very odd symptoms this caused. Sometimes, when you flicked the "ground lift" switch on the back panel, the fans would start up at full chat, and a sound that can best be described as a drone pipe on a set of bagpipes, ramped up as the fans ran up. Very odd indeed. So, where do I find this PPrune board ? Arfa |
Post mortem on an IEC connector
In article ,
"Arfa Daily" wrote: Still, apparently, they have now located some wreckage 400 miles out into the Atlantic, so I guess that they have around 28 days left to locate and recover the CVR and FDR boxes, which apparently are likely to be lying in around 13000 feet of water. Seems like the batteries for the pingers are good for about 30 days, and the transmitter is just about man enough to get a signal through 15000 feet of salt water. I guess that if they can recover them and they continued to function for any time after the initial 'event', then we could know quite quickly what the primary cause of it going down was. This whole "black box recovery" stuff seems silly to me. Given the number of accidents in which the recorders are never found, or when found are FUBAR, and given today's communications technology, I don't know why data isn't being constantly streamed to ground recording centers. |
Post mortem on an IEC connector
Smitty Two wrote:
In article , "Arfa Daily" wrote: Still, apparently, they have now located some wreckage 400 miles out into the Atlantic, so I guess that they have around 28 days left to locate and recover the CVR and FDR boxes, which apparently are likely to be lying in around 13000 feet of water. Seems like the batteries for the pingers are good for about 30 days, and the transmitter is just about man enough to get a signal through 15000 feet of salt water. I guess that if they can recover them and they continued to function for any time after the initial 'event', then we could know quite quickly what the primary cause of it going down was. This whole "black box recovery" stuff seems silly to me. Given the number of accidents in which the recorders are never found, or when found are FUBAR, and given today's communications technology, I don't know why data isn't being constantly streamed to ground recording centers. Technically, that'd be a bit tricky on (for example) a trip between New York & London. -- W . | ,. w , "Some people are alive only because \|/ \|/ it is illegal to kill them." Perna condita delenda est ---^----^--------------------------------------------------------------- |
Post mortem on an IEC connector
"Smitty Two" wrote in message ... In article , "Arfa Daily" wrote: Still, apparently, they have now located some wreckage 400 miles out into the Atlantic, so I guess that they have around 28 days left to locate and recover the CVR and FDR boxes, which apparently are likely to be lying in around 13000 feet of water. Seems like the batteries for the pingers are good for about 30 days, and the transmitter is just about man enough to get a signal through 15000 feet of salt water. I guess that if they can recover them and they continued to function for any time after the initial 'event', then we could know quite quickly what the primary cause of it going down was. This whole "black box recovery" stuff seems silly to me. Given the number of accidents in which the recorders are never found, or when found are FUBAR, and given today's communications technology, I don't know why data isn't being constantly streamed to ground recording centers. Ah. A point that I made to my pilot friend yesterday, and apparently, some of the flight data is streamed to the ACARS system continuously, via satellite. He says that height, speed, heading, inertial nav position estimate, and true GPS position, amongst other things, are transmitted. Which then begs the question of why it is so difficult to locate the position of a downed aircraft. I guess that if it is coming down from 7 miles up, with significant forward speed, and not necessarily in one piece, that might make it more difficult. Still, I would have thought that it would have given them a bit more of a 'ball park' area to be looking in, than seems to be the case. In fact, I remember seeing an episode of ACI, where they took the place of last transmission of an aircraft, and then plotted by computer, how the pieces would fall, and came up with a location for a door I think it was, which struck me as pretty clever. But yes. Given the level of compression that can be applied to data streams these days, it does seem archaic to record all this data on board the item that you are trying to protect. I suppose privacy issues might come into transmitting flight deck chat, but I'm sure that with the encryption systems available, and operating the same rolling window system, that could be overcome. I also questioned the state these boxes are in when found, but he said not to be misled by their appearance. Apparently, if they were working in the first place - and that's not always a given, which is a bit worrying - the chances are that they will still be working when recovered. Seems that the actual recorder is inside a sphere, and the battered bit that you always see, is just an outer case, which might contain some ancilliary electronics, and is shaped to fit a rack in an equipment bay. Also, these days, they employ solid state memory, rather than any kind of electro-mechanical recording mech. Arfa Arfa |
Post mortem on an IEC connector
Arfa Daily wrote in message
... "Smitty Two" wrote in message ... In article , "Arfa Daily" wrote: Still, apparently, they have now located some wreckage 400 miles out into the Atlantic, so I guess that they have around 28 days left to locate and recover the CVR and FDR boxes, which apparently are likely to be lying in around 13000 feet of water. Seems like the batteries for the pingers are good for about 30 days, and the transmitter is just about man enough to get a signal through 15000 feet of salt water. I guess that if they can recover them and they continued to function for any time after the initial 'event', then we could know quite quickly what the primary cause of it going down was. This whole "black box recovery" stuff seems silly to me. Given the number of accidents in which the recorders are never found, or when found are FUBAR, and given today's communications technology, I don't know why data isn't being constantly streamed to ground recording centers. Ah. A point that I made to my pilot friend yesterday, and apparently, some of the flight data is streamed to the ACARS system continuously, via satellite. He says that height, speed, heading, inertial nav position estimate, and true GPS position, amongst other things, are transmitted. Which then begs the question of why it is so difficult to locate the position of a downed aircraft. I guess that if it is coming down from 7 miles up, with significant forward speed, and not necessarily in one piece, that might make it more difficult. Still, I would have thought that it would have given them a bit more of a 'ball park' area to be looking in, than seems to be the case. In fact, I remember seeing an episode of ACI, where they took the place of last transmission of an aircraft, and then plotted by computer, how the pieces would fall, and came up with a location for a door I think it was, which struck me as pretty clever. But yes. Given the level of compression that can be applied to data streams these days, it does seem archaic to record all this data on board the item that you are trying to protect. I suppose privacy issues might come into transmitting flight deck chat, but I'm sure that with the encryption systems available, and operating the same rolling window system, that could be overcome. I also questioned the state these boxes are in when found, but he said not to be misled by their appearance. Apparently, if they were working in the first place - and that's not always a given, which is a bit worrying - the chances are that they will still be working when recovered. Seems that the actual recorder is inside a sphere, and the battered bit that you always see, is just an outer case, which might contain some ancilliary electronics, and is shaped to fit a rack in an equipment bay. Also, these days, they employ solid state memory, rather than any kind of electro-mechanical recording mech. Arfa Arfa I thought they retained wire recording, as the data survived fire temperatures above the 150C of Si which is easily exceeded in a sustained fire , up to something close to the melting point of steel. I see the recent Quantas airbourne rollercoaster affair, over Oz, is now deemed RFI intrusion. I liked the scenario of the prime-minister's motorcade, anti-bomb detonation phone-jammer system passing underneath that Boeing that crash landed at Heathrow last year, just as the fuel management system failed. Compareed to the official version of 2 separate fuel jelling/icing events coinciding -- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on http://home.graffiti.net/diverse:graffiti.net/ |
Post mortem on an IEC connector
In article ,
Bob Larter wrote: Smitty Two wrote: In article , "Arfa Daily" wrote: Still, apparently, they have now located some wreckage 400 miles out into the Atlantic, so I guess that they have around 28 days left to locate and recover the CVR and FDR boxes, which apparently are likely to be lying in around 13000 feet of water. Seems like the batteries for the pingers are good for about 30 days, and the transmitter is just about man enough to get a signal through 15000 feet of salt water. I guess that if they can recover them and they continued to function for any time after the initial 'event', then we could know quite quickly what the primary cause of it going down was. This whole "black box recovery" stuff seems silly to me. Given the number of accidents in which the recorders are never found, or when found are FUBAR, and given today's communications technology, I don't know why data isn't being constantly streamed to ground recording centers. Technically, that'd be a bit tricky on (for example) a trip between New York & London. Really? So transatlantic flights are out of contact with flight control? |
Post mortem on an IEC connector
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Post mortem on an IEC connector
electronics, and is shaped to fit a rack in an equipment bay. Also, these days, they employ solid state memory, rather than any kind of electro-mechanical recording mech. Arfa I thought they retained wire recording, as the data survived fire temperatures above the 150C of Si which is easily exceeded in a sustained fire , up to something close to the melting point of steel. I see the recent Quantas airbourne rollercoaster affair, over Oz, is now deemed RFI intrusion. Probably some old VK checking if 10 metres has started opening yet ... !! I liked the scenario of the prime-minister's motorcade, anti-bomb detonation phone-jammer system passing underneath that Boeing that crash landed at Heathrow last year, just as the fuel management system failed. Compareed to the official version of 2 separate fuel jelling/icing events coinciding Yes. That was an odd one. Given that the thing landed basically intact, with a fully alive crew and completely undamaged flight recorders, it seemed strange to me that they would very quickly wheel it away into a hangar, and then take months to reach this conclusion. They talked about the thing passing through an area of very cold air, and on some of the news reports that I heard, they were talking "below -50 deg C". However, when you fly across the Atlantic at 38000 feet, the temperature is always at around -56 deg C the whole way, according to the flight data display available as an entertainment channel, and it doesn't seem to cause a problem. I'm sure that designers must know this, and take it into account when working out the fuel delivery and storage systems. When you think about how much (expensive) systems redundancy is built into jet airliners in the pursuit of safety, it would be a pretty unforgivable design oversight to make the fuel system not able to cope with a few tens of degrees colder than it would normally expect to encounter, wouldn't it ? Arfa |
Post mortem on an IEC connector
"Smitty Two" wrote in message ... In article , Bob Larter wrote: Smitty Two wrote: In article , "Arfa Daily" wrote: Still, apparently, they have now located some wreckage 400 miles out into the Atlantic, so I guess that they have around 28 days left to locate and recover the CVR and FDR boxes, which apparently are likely to be lying in around 13000 feet of water. Seems like the batteries for the pingers are good for about 30 days, and the transmitter is just about man enough to get a signal through 15000 feet of salt water. I guess that if they can recover them and they continued to function for any time after the initial 'event', then we could know quite quickly what the primary cause of it going down was. This whole "black box recovery" stuff seems silly to me. Given the number of accidents in which the recorders are never found, or when found are FUBAR, and given today's communications technology, I don't know why data isn't being constantly streamed to ground recording centers. Technically, that'd be a bit tricky on (for example) a trip between New York & London. Really? So transatlantic flights are out of contact with flight control? That certainly used to be the case. Most 'regular' civilian ATC takes place on VHF, which obviously has quite limited range. Transatlantic airliners do stay in contact with their own offices via HF SSB I believe, using a sel-call system. I believe that weather reports are also communicated likewise. I don't suppose that there is much need for ATC when mid Atlantic. Your course is pretty much pre-planned and established, barring odd unforseen circumstances. ATC monitoring used to be a bit of a hobby of mine, but I haven't kept up to date with it. Maybe these days, they are in touch with someone constantly. I guess it wouldn't be that difficult via satellite, especially if they are already relaying ACARS data in that way, as my pilot friend says they are. Ah. Here ya go ... http://www.prnewswire.co.uk/cgi/news/release?id=51137 Arfa |
Post mortem on an IEC connector
Smitty Two wrote:
In article , Bob Larter wrote: Smitty Two wrote: In article , "Arfa Daily" wrote: Still, apparently, they have now located some wreckage 400 miles out into the Atlantic, so I guess that they have around 28 days left to locate and recover the CVR and FDR boxes, which apparently are likely to be lying in around 13000 feet of water. Seems like the batteries for the pingers are good for about 30 days, and the transmitter is just about man enough to get a signal through 15000 feet of salt water. I guess that if they can recover them and they continued to function for any time after the initial 'event', then we could know quite quickly what the primary cause of it going down was. This whole "black box recovery" stuff seems silly to me. Given the number of accidents in which the recorders are never found, or when found are FUBAR, and given today's communications technology, I don't know why data isn't being constantly streamed to ground recording centers. Technically, that'd be a bit tricky on (for example) a trip between New York & London. Really? So transatlantic flights are out of contact with flight control? I honestly don't know, but I assume they would be for at least part of the trip. But even if I'm wrong about that, I doubt that there'd be the bandwidth available for every plane in the air to be continuously streaming 20+ channels of telemetry, etc, back to base. -- W . | ,. w , "Some people are alive only because \|/ \|/ it is illegal to kill them." Perna condita delenda est ---^----^--------------------------------------------------------------- |
Post mortem on an IEC connector
Meat Plow wrote:
On Fri, 05 Jun 2009 11:47:44 +1000, Bob Larter wrote: Smitty Two wrote: In article , Bob Larter wrote: Smitty Two wrote: In article , "Arfa Daily" wrote: Still, apparently, they have now located some wreckage 400 miles out into the Atlantic, so I guess that they have around 28 days left to locate and recover the CVR and FDR boxes, which apparently are likely to be lying in around 13000 feet of water. Seems like the batteries for the pingers are good for about 30 days, and the transmitter is just about man enough to get a signal through 15000 feet of salt water. I guess that if they can recover them and they continued to function for any time after the initial 'event', then we could know quite quickly what the primary cause of it going down was. This whole "black box recovery" stuff seems silly to me. Given the number of accidents in which the recorders are never found, or when found are FUBAR, and given today's communications technology, I don't know why data isn't being constantly streamed to ground recording centers. Technically, that'd be a bit tricky on (for example) a trip between New York & London. Really? So transatlantic flights are out of contact with flight control? I honestly don't know, but I assume they would be for at least part of the trip. But even if I'm wrong about that, I doubt that there'd be the bandwidth available for every plane in the air to be continuously streaming 20+ channels of telemetry, etc, back to base. Commercial lines have GPS tracking and sat communications if needed. Plus there are many HF channels for flight control and military tracking stations located strategically upon small islands, atolls, etc.. that would surely assist commercial aviators. Yeah, but Jeez, that'd be an incredible effort to go to! -- W . | ,. w , "Some people are alive only because \|/ \|/ it is illegal to kill them." Perna condita delenda est ---^----^--------------------------------------------------------------- |
Post mortem on an IEC connector
On Thu, 28 May 2009 01:52:41 +0100, "Arfa Daily"
wrote: So do I, my friend, as I am about to get on one for the first time in October. All of my previous cross-pond jaunts have been in properly built 747s, which have a proper yoke for the driver to hang on to, and 'automatics' that can be switched off. Boeings have always had issues with their design. 737 rudder hydraulics for example were a death trap waiting to happen and some ****wits let them keep flying despite a serious design issue being known about for 15 years... and as for the 747, we have fuel tanks that explode, engines that fall off, lightning strikes that make the wing fall off to name but a few. Walk around a Boeing assembly plant, or previously an MD plant and you see workers in casual street clothes, keys hanging off their waistband, loose items in their pockets. Walk around an Airbus plant and you see workers in specific work clothes with *no* pockets, with tight control on personnel access and all losses of hardware being fully investigated. At Boeing you get birds nesting in the structures and people eating food, people dropping small items and just picking another one from a parts bin with no regard for where the stray bits end up. Look at the number of foreign objects found in nooks and crannies on Boeing aircraft during their maintenance stripdowns - a full size sweeping brush FFS! numerous coins, numerous spare fasteners, a mouldy sandwich, even huge ring binders stuffed with 'QA documentation' There's something fundamentally wrong about a plane that has to be flown with a left-handed joystick, Then sit in the other seat with a right handed joystick. and which employs a robot driver hidden away somewhere, which believes it knows more about how to fly a plane, than the human guy and his chum in the co-seat, who have 40 years flying experience between them ... :-\ The robot driver *usually* *does* know more, but not always. -- |
Post mortem on an IEC connector
"Mike" wrote in message ... On Thu, 28 May 2009 01:52:41 +0100, "Arfa Daily" wrote: So do I, my friend, as I am about to get on one for the first time in October. All of my previous cross-pond jaunts have been in properly built 747s, which have a proper yoke for the driver to hang on to, and 'automatics' that can be switched off. Boeings have always had issues with their design. 737 rudder hydraulics for example were a death trap waiting to happen and some ****wits let them keep flying despite a serious design issue being known about for 15 years... and as for the 747, we have fuel tanks that explode, engines that fall off, lightning strikes that make the wing fall off to name but a few. Walk around a Boeing assembly plant, or previously an MD plant and you see workers in casual street clothes, keys hanging off their waistband, loose items in their pockets. Walk around an Airbus plant and you see workers in specific work clothes with *no* pockets, with tight control on personnel access and all losses of hardware being fully investigated. At Boeing you get birds nesting in the structures and people eating food, people dropping small items and just picking another one from a parts bin with no regard for where the stray bits end up. Look at the number of foreign objects found in nooks and crannies on Boeing aircraft during their maintenance stripdowns - a full size sweeping brush FFS! numerous coins, numerous spare fasteners, a mouldy sandwich, even huge ring binders stuffed with 'QA documentation' There's something fundamentally wrong about a plane that has to be flown with a left-handed joystick, Then sit in the other seat with a right handed joystick. and which employs a robot driver hidden away somewhere, which believes it knows more about how to fly a plane, than the human guy and his chum in the co-seat, who have 40 years flying experience between them ... :-\ The robot driver *usually* *does* know more, but not always. -- Conventionally, a fixed wing pilot sits in the left seat. This is a hangover from airfields having a left hand circuit for fixed wings, so on the circuit leg turns, the bank is in the direction that the pilot has a view of the ground and is able to see that he does not overshoot his turn points. Obviously, that does not apply with airport 'straight in' long finals approaches, but I don't think that you really want to be having one flight deck seating convention for one plane, and the opposite for another. As far as the robot knowing more than a human pilot, on paper that might be true. But sometimes, complex tasks like flying require dynamic 'outside the box' thinking to handle unforseen circumstances, and that is where the experience and flexible thought processes of an experienced flight crew, might just make the difference. With the A330 incident, AF investigators have today announced that the automatic ACARS error messages were streaming events of "inconsistent height" and "inconsistent speed", which they think may have been due to the automatic throttles cycling as a result of the heavy turbulence which the pilot had declared he was encountering, using the ACARS manual text messaging option. Presumably, if that was what was actually occuring, it would not have been desirable, and the pilot would have been aware of it, so is this an example of a total fly by wire control system that the pilot cannot disengage, and operate manually ? The trouble is that once you've thrown away the yoke and other manual controls, there's no going back. I don't have a basic problem with a fly by wire system, but I think that the option of over-riding it in exceptional circumstances, and when agreed by both crew, is the sensible one. If you totally lose the computer systems, or have a total electrical failure on one of these planes, then that's it. You are screwed every which way, and you are going to die. If you have a similar failure on a plane which has a triple redundancy hydraulically linked set of controls, then provided that the fluid resevoirs retain some system pressure, there's a good chance that the pilot is going to be able to at least make a controlled descent, and possibly even a successful landing. Arfa |
Post mortem on an IEC connector
"Mike" wrote in message ... On Thu, 28 May 2009 01:52:41 +0100, "Arfa Daily" wrote: So do I, my friend, as I am about to get on one for the first time in October. All of my previous cross-pond jaunts have been in properly built 747s, which have a proper yoke for the driver to hang on to, and 'automatics' that can be switched off. Boeings have always had issues with their design. 737 rudder hydraulics for example were a death trap waiting to happen and some ****wits let them keep flying despite a serious design issue being known about for 15 years... and as for the 747, we have fuel tanks that explode, engines that fall off, lightning strikes that make the wing fall off to name but a few. Walk around a Boeing assembly plant, or previously an MD plant and you see workers in casual street clothes, keys hanging off their waistband, loose items in their pockets. Walk around an Airbus plant and you see workers in specific work clothes with *no* pockets, with tight control on personnel access and all losses of hardware being fully investigated. At Boeing you get birds nesting in the structures and people eating food, people dropping small items and just picking another one from a parts bin with no regard for where the stray bits end up. Look at the number of foreign objects found in nooks and crannies on Boeing aircraft during their maintenance stripdowns - a full size sweeping brush FFS! numerous coins, numerous spare fasteners, a mouldy sandwich, even huge ring binders stuffed with 'QA documentation' There's something fundamentally wrong about a plane that has to be flown with a left-handed joystick, Then sit in the other seat with a right handed joystick. and which employs a robot driver hidden away somewhere, which believes it knows more about how to fly a plane, than the human guy and his chum in the co-seat, who have 40 years flying experience between them ... :-\ The robot driver *usually* *does* know more, but not always. -- Conventionally, a fixed wing pilot sits in the left seat. This is a hangover from airfields having a left hand circuit for fixed wings, so on the circuit leg turns, the bank is in the direction that the pilot has a view of the ground and is able to see that he does not overshoot his turn points. Obviously, that does not apply with airport 'straight in' long finals approaches, but I don't think that you really want to be having one flight deck seating convention for one plane, and the opposite for another. As far as the robot knowing more than a human pilot, on paper that might be true. But sometimes, complex tasks like flying require dynamic 'outside the box' thinking to handle unforseen circumstances, and that is where the experience and flexible thought processes of an experienced flight crew, might just make the difference. With the A330 incident, AF investigators have today announced that the automatic ACARS error messages were streaming events of "inconsistent height" and "inconsistent speed", which they think may have been due to the automatic throttles cycling as a result of the heavy turbulence which the pilot had declared he was encountering, using the ACARS manual text messaging option. Presumably, if that was what was actually occuring, it would not have been desirable, and the pilot would have been aware of it, so is this an example of a total fly by wire control system that the pilot cannot disengage, and operate manually ? The trouble is that once you've thrown away the yoke and other manual controls, there's no going back. I don't have a basic problem with a fly by wire system, but I think that the option of over-riding it in exceptional circumstances, and when agreed by both crew, is the sensible one. If you totally lose the computer systems, or have a total electrical failure on one of these planes, then that's it. You are screwed every which way, and you are going to die. If you have a similar failure on a plane which has a triple redundancy hydraulically linked set of controls, then provided that the fluid resevoirs retain some system pressure, there's a good chance that the pilot is going to be able to at least make a controlled descent, and possibly even a successful landing. Arfa |
Post mortem on an IEC connector
"Meat Plow" wrote in message ... On Fri, 05 Jun 2009 22:51:14 +0100, Mike wrote: On Thu, 28 May 2009 01:52:41 +0100, "Arfa Daily" wrote: So do I, my friend, as I am about to get on one for the first time in October. All of my previous cross-pond jaunts have been in properly built 747s, which have a proper yoke for the driver to hang on to, and 'automatics' that can be switched off. Boeings have always had issues with their design. 737 rudder hydraulics for example were a death trap waiting to happen and some ****wits let them keep flying despite a serious design issue being known about for 15 years... and as for the 747, we have fuel tanks that explode, engines that fall off, lightning strikes that make the wing fall off to name but a few. The 737 issue was with the rudder screw. An engine that fell from I think an AA DC10 was caused by a pylon fitting that was damaged by a engine refit. Flight 800 fuel tank exploded under extraordinary conditions and was corrected. As far as lightning taking out a wing, what flight was that? Walk around a Boeing assembly plant, or previously an MD plant and you see workers in casual street clothes, keys hanging off their waistband, loose items in their pockets. Walk around an Airbus plant and you see workers in specific work clothes with *no* pockets, with tight control on personnel access and all losses of hardware being fully investigated. At Boeing you get birds nesting in the structures and people eating food, people dropping small items and just picking another one from a parts bin with no regard for where the stray bits end up. Look at the number of foreign objects found in nooks and crannies on Boeing aircraft during their maintenance stripdowns - a full size sweeping brush FFS! numerous coins, numerous spare fasteners, a mouldy sandwich, even huge ring binders stuffed with 'QA documentation' Didn't an Airbus 310's rudder rip completely off the fuselage a few years ago. Boeing has been making some pretty reliable military and civilian aircraft for 60 years. Airbus? There's something fundamentally wrong about a plane that has to be flown with a left-handed joystick, Then sit in the other seat with a right handed joystick. and which employs a robot driver hidden away somewhere, which believes it knows more about how to fly a plane, than the human guy and his chum in the co-seat, who have 40 years flying experience between them ... :-\ The robot driver *usually* *does* know more, but not always. All newer military aircraft depend entirely upon a 'robot' to fly them. A human can't respond fast enough to fly an aircraft purposefully designed to be aerodynamically unstable like the F/A 117, F16, YF 22, F 18/e. The thing is though that the FBW systems on a fighter aircraft are not quite the same as on a civilian airliner. Military aircraft are designed with having the pilot being able to throw them around the sky in a tactical manner in mind. This is the reason that they don't actually 'fly', and the reason that a computer system is needed to interpret the stick inputs from the pilot, and analyse the many conditions that prevail at that moment, and then give the control surfaces the appropriate input to make this unstable missile, do what the pilot wants it to. On the other hand, a jet airliner is not an unstable lump, and does fly all on its own. Responses for inputs are absolutely predictable. Given that we are talking about the safety of several hundreds of civilians here, I really would prefer that if anything went wrong with the automatic decisions of the FBW, or even if there was a massive systems failure, that the pilot at least had a fighting chance of being able to manually control the aircraft, instead of just sitting in his seat waiting to hit the ground ... I can see the point of FBW systems on fighter aircraft, but the reason for having them on civilian airliners, eludes me. It's all very well saying that they eliminate pilot error, but it seems that they are also responsible for 'machine error' accidents. I was talking to my aviator friend again today, and he says that there have been many low altitude incidents where the robot has got it wrong, resulting in wing waggles and roller coaster rides. The thing is, the general public don't really hear about them, as they are not castrophic events. Apparently, Airbus are now speeding up the replacement of Pitot heads on all their aircraft. Something to do with the anti-ice heater not being good enough. Makes you wonder whether the error messages that were sent on the ACARS, followed a pattern that had been seen before, and was known to be associated with Pitot tube icing ... Arfa |
Post mortem on an IEC connector
Meat Plow wrote in message
... On Fri, 05 Jun 2009 22:51:14 +0100, Mike wrote: On Thu, 28 May 2009 01:52:41 +0100, "Arfa Daily" wrote: So do I, my friend, as I am about to get on one for the first time in October. All of my previous cross-pond jaunts have been in properly built 747s, which have a proper yoke for the driver to hang on to, and 'automatics' that can be switched off. Boeings have always had issues with their design. 737 rudder hydraulics for example were a death trap waiting to happen and some ****wits let them keep flying despite a serious design issue being known about for 15 years... and as for the 747, we have fuel tanks that explode, engines that fall off, lightning strikes that make the wing fall off to name but a few. The 737 issue was with the rudder screw. An engine that fell from I think an AA DC10 was caused by a pylon fitting that was damaged by a engine refit. Flight 800 fuel tank exploded under extraordinary conditions and was corrected. As far as lightning taking out a wing, what flight was that? Walk around a Boeing assembly plant, or previously an MD plant and you see workers in casual street clothes, keys hanging off their waistband, loose items in their pockets. Walk around an Airbus plant and you see workers in specific work clothes with *no* pockets, with tight control on personnel access and all losses of hardware being fully investigated. At Boeing you get birds nesting in the structures and people eating food, people dropping small items and just picking another one from a parts bin with no regard for where the stray bits end up. Look at the number of foreign objects found in nooks and crannies on Boeing aircraft during their maintenance stripdowns - a full size sweeping brush FFS! numerous coins, numerous spare fasteners, a mouldy sandwich, even huge ring binders stuffed with 'QA documentation' Didn't an Airbus 310's rudder rip completely off the fuselage a few years ago. Boeing has been making some pretty reliable military and civilian aircraft for 60 years. Airbus? There's something fundamentally wrong about a plane that has to be flown with a left-handed joystick, Then sit in the other seat with a right handed joystick. and which employs a robot driver hidden away somewhere, which believes it knows more about how to fly a plane, than the human guy and his chum in the co-seat, who have 40 years flying experience between them ... :-\ The robot driver *usually* *does* know more, but not always. All newer military aircraft depend entirely upon a 'robot' to fly them. A human can't respond fast enough to fly an aircraft purposefully designed to be aerodynamically unstable like the F/A 117, F16, YF 22, F 18/e. Surely they've reached the 21 century and don't rely on pitot tubes alone. Surely X,Y,Z GPS with over-the-land interpolated speed which should agree with the pitot figures when wind speed taken is taken into account. |
Post mortem on an IEC connector
I heard it was pitot icing which isn't supposed to happen on heated pitots which all icing condition certified aircraft should have. Take away that info gather by the pitots and you disable the aircraft's ability to process flight dynamics. Pitot readings indicated a lower than normal airspeed, the engines throttle up and the aircraft then flies too fast for the turbulent conditions causing a catastrophic failure of the airframe. Decompression occurs and the airframe breaks apart at FL 330. Yeah. Lots of interesting stuff coming out now. From today's newspaper -- " ..... investigators said that the Airbus's pilots had no idea how fast they were flying after sensors iced up and the computer went haywire. The computer sent 24 error messages and was flying without autopilot or cruise control. ..... it was not clear whether the autopilot had been switched off, or had stopped working. Mets said the jet flew into a freak storm with 100mph updraughts that sucked up seawater that quickly froze. ..... said the lack of speed readings meant the pilots would have stalled or used more power than the jet could take." Taking N.Cook's point about the Pitot being only one input. This is true, with there being secondary inputs from the INS and from GPS. However, as the Pitot data is fundamentally 'mechanical', it is considered the data of primary reliability. Presumably, the fact that it was (possibly) giving erroneous readings, should have led to the data from the other two sources being taken into account, and a two out of three decision made on that basis, but there may be a software conflict situation arising out of that. I don't know if that aircraft has one or two tubes, but if it has two, and they were both icing and giving the same wrong reading, that may have been enough to screw the decision making process. My flying chum says that as well as ramping the engines up, if the flight control systems decide that the airspeed is still not going up, then it may well put the nose down as well in an effort to increase the speed. Then you are in a full power dive. The ACARS error messages are purely for advance maintenance purposes, and are simplistic in that if the pilot switches a system off - such as the autopilot or the auto cruise control - this will immediately trigger exactly the same 'error' message as if the system had failed on its own. There is no distinction between a failure and a deliberate disconnect. Either way, it is an 'error'. The bad thing is though, that if the system is then switched back on (or recovers from a temporary fault), this does not trigger a different message to say it's back on. It is just an error that has now gone away again. Another interesting point is that the aircraft took on every last ounce of fuel that it could, before leaving Rio. Not so much that it was overloaded out of spec, but much more than it would have needed for the flight with divert margin. So this might mean that the pilot was aware of the massive storm on his proposed routing, and was covering for the possibility of having to go around it. However, all of this extra fuel meant that he could not attain his filed flightplan cruise altitude of FL370, and was instead, at a radio approved FL350. If it does turn out to be down to Pitot icing, and this was a known problem, I wonder if a charge of corporate culpability will be levelled at Airbus ? That one that you mentioned where the tail fell off, I seem to recall that was due to a stress fracture in the composite which was repaired with a horseshoe of ally rivetted on over it. This is a valid repair technique for an ally skin fracture, but not for composite. I believe that there are no approved techniques for repairing this kind of problem, in this kind of material. Apparently the aircraft that has just gone down, was involved in a ground collision a couple of years back, when its wing hit the tail of another aircraft, doing that tail serious damage. I wonder if any unseen latent damage was done to the Airbus's wing, that then failed in the turbulence / excess power conditions ? Arfa |
Post mortem on an IEC connector
Returning to lightning , this news report from yesterday - perhaps there
should be a return to thermionic valves for safety reasons http://news.bbc.co.uk/1/hi/england/dorset/8087964.stm Page last updated at 14:44 GMT, Sunday, 7 June 2009 15:44 UK Fishermen rescued in thunderstorm Poole lifeboat Sgt Bob Martin The new Poole RNLI inshore lifeboat took part in the rescues Two fishermen had to be rescued after they became cut off and were unable to return to shore during a thunderstorm off Dorset. Relatives of the men, who had been out fishing all day, alerted the coastguard when they had not returned by midnight. The Poole RNLI lifeboats located the men's motorboat and dinghy in the harbour. Their radio, phone and mobiles had been put out by the electric storm. They were transferred to the lifeboat and taken back to shore unhurt. Gavin McGuinness, volunteer helmsman, said: "They did the right thing staying put. It was the worst conditions I have seen for some time. "The visibility was poor, the rain was hitting us like ball bearings out of a machine gun, sheets of rain interspersed by bolts of lightning made conditions horrendous". "Huge bolts of lightning bouncing of the water all round the harbour, lighting up the night skies, it was very close to the boats." He said the torrential rain had also blanked out the radar. |
Post mortem on an IEC connector
Surely they've reached the 21 century and don't rely on pitot tubes alone. Surely X,Y,Z GPS with over-the-land interpolated speed which should agree with the pitot figures when wind speed taken is taken into account. I'm going by military specs of the F117 which NEEDS 3 working pitots or it cannot be flown. Don't know how many pitots a 330 has but certainly the fly by wire systems have similarities, this is just my assumption remember. For immediate control of the aircraft, the computers need at lease 3 axis of information for fundamental control. Since the pitot has been around forever I again assume they play a very large role in the guidance systems. My flying oppo says that there are speed inputs from the inertial nav and GPS, but that the pitot input is the speed data of primary reliability, precisely because it is a simple device, and a 'known', as you say, for many many years. I put the lunchtime news on today to see if there had been any further announcements. In the section "coming up in today's programme", they showed pictures of the tail floating in the ocean, with divers standing on it, and made some comments about that being found, and the body count now being up to 29. Then they said words to the effect of "investigators are still focusing on erroneous data from external speed sensors, being the cause of the 'accident' ". However, when it came to the actual news item playing some time later in the show, there was absolutely no further mention of this, and almost all of the item concentrated on pictures of the wreckage, and the base where bodies are being taken. Strange. I wonder whether the original comment was just a leftover from yesterday when they were saying this, put in to time-pad the excerpt, or whether the broadcast was edited on the fly to take out this aspect for some reason ... Arfa |
Post mortem on an IEC connector
an almost total waste of time , as far as technical info , More 4 prog last
night was about lightning. Somewhere in the visuals (unexplained) was a distant piece of film/video of a plane being struck by lightning and passing round to the other side to continiue the arc to another bit of cloud |
Post mortem on an IEC connector
On Sat, 06 Jun 2009 10:29:37 -0400, Meat Plow
wrote: On Fri, 05 Jun 2009 22:51:14 +0100, Mike wrote: Boeings have always had issues with their design. 737 rudder hydraulics for example were a death trap waiting to happen and some ****wits let them keep flying despite a serious design issue being known about for 15 years... and as for the 747, we have fuel tanks that explode, engines that fall off, lightning strikes that make the wing fall off to name but a few. The 737 issue was with the rudder screw. No, it's not *that* rudder problem which was on the MD80 and a lubrication (or lack of) issue. The 737's problem was associated with actuator reversal. Pilot commands right rudder and gets left, commands left rudder and gets right. Planes kept falling out of the sky killing all on board, one pilot survived and told them what happened yet Boeing still said it *couldn't* happen. Eventually they found out it did, and then, with greta releuctance finally agreed to modify the actuators. http://en.wikipedia.org/wiki/Boeing_737_rudder_issues An engine that fell from I think an AA DC10 was caused by a pylon fitting that was damaged by a engine refit. Happened on 747's too http://en.wikipedia.org/wiki/El_Al_Flight_1862 Flight 800 fuel tank exploded under extraordinary conditions and was corrected. As far as lightning taking out a wing, what flight was that? Yet another 747, 9th May 1976 near Madrid http://aviation-safety.net/database/...?id=19760509-0 Didn't an Airbus 310's rudder rip completely off the fuselage a few years ago. Yes, in October 2001 near NYC Boeing has been making some pretty reliable military and civilian aircraft for 60 years. Airbus? 39 years, the heritage of the constituent companies of Airbus goes back way before then though. 'Airbus' were crashing planes when Mr Boeing was still in short pants :) All newer military aircraft depend entirely upon a 'robot' to fly them. A human can't respond fast enough to fly an aircraft purposefully designed to be aerodynamically unstable like the F/A 117, F16, YF 22, F 18/e. There is no element of response on such aircraft, you often have to move controls in completely the opposite direction and at a different rate to what you might perceive to be the right one :) -- |
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