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Comment Re:An engineer's reaction CORRECTED (Score 3, Informative) 505

Somewhere there is an engineer that argued quite vehemently that there is no way the air speed sensors on an Airbus A330 could possibly all fail

There is/was no engineer that argued this. Instead the argument was, "if this happens, what can we do to improve safety in that event?" That failure mode was thought of, I have absolutely no doubt. Engineers thought it was covered, they may have been wrong about that but I'll discuss that later.

leading the engines to stall in mid-flight

An aircraft stalling does not involve the engines, it involves airflow over the wings. Do you have any knowledge of the topic at all? Nothing I've read indicates there was an engine failure on that flight.

The aircraft crashed because when readings became invalid, the computer automatically disconnected the autopilot / autothrottle (as it should have). The pilots then made control inputs that were inappropriate for the situation. They were probably confused by the relative lack of data they had, and the multitude of warnings a complete air data failure causes. The pilots then held a nose up attitude through multiple stall warnings, eventually entering a period of extremely high sink rate. The aircraft had pitched up in excess of 35 degrees through this period, and the pilots held full nose up control inputs through almost all of it. It was the exact opposite of what they should have been doing. The pilots held the stall all the way into the ocean, impacting the water while still in a nose up attitude of more than 16 degrees.

I know people like to get up in arms whenever a crash is blamed on pilot error, but it's pretty clear in this case that the pilot's actions were inappropriate and their inability to recover from the stall despite ample opportunity will almost certainly be listed as the main cause of the accident. There were many contributing factors, but the data suggests that the aircraft would have flown just fine if given proper stall recovery inputs.

What could the engineers have done better? Indicate in a more useful way what was going on and which instruments were reliable. The pilots should have been able to tell at a glance what they should pay attention to and what they should ignore. The avionics display design may not have been good enough for them to do that. The stall warning may have deactivated inappropriately based on the invalid speed, because the computer thought the aircraft was traveling too slow for the angle of attack indicators to function correctly. This failure mode should not exist in my opinion. Either the angle of attack indicator should function at lower speeds, or an alternate stall indication should be used instead. Or just keep the warning on, since the aircraft is quite obviously not in landing configuration. From what I read, they were probably assaulted with a whole host of failure warnings that were confusing and may have contributed to a panic reaction.
Also, pilot training needs to be improved in some areas, especially involving loss of pitot static data. There is no reason an airplane of any type should crash because of a clogged pitot tube. This should be drilled into pilots starting with the most basic beginning flight training. I know from experience the topic is not covered at that level, besides a couple questions that may appear on the knowledge test. In fact, if I had not actually had a pitot tube get clogged during my training, I would have never encountered the situation at all.

There's some fairly good discussion about the events of the flight here.

Comment Re:Mark Cuban (Score 1) 427

And analyzing flight plans of planes that report it to a government entity is no more an invasion of privacy than my mortgage info and home address being a matter of public record.

The entire point of the above articles is that this information was NOT a matter of public record. This request revealed information about all flights, including flights that were previously blocked from public view for privacy reasons. The government sure as hell has no business handing out the travel habits of everyone for public consumption. This isn't even remotely comparable to having your home address linked with your name, it's more like showing every movement your car has ever made.

Comment Re:PS3 Issues (Score 1) 196

where the manufacturer has full control of... [the] airflow path inside the chassis

The incredibly piss poor design of the original 360 in terms of airflow amazes me. You'd think that they would have at the very least brought someone in to do some basic consulting on heat dissipation in the case, but obviously they didn't spend any time at all thinking about it.

Seriously, if I remember right there were only two small exhaust fans in the entire system. Processor / Graphics were cooled only by a passive heatsink, nowhere near the intake of those fans. The only way to get any appreciable airflow past that heatsink would be to use a very restrictive shroud that forced those fan's intake to pass over the heatsinks. They used nothing. Nothing at all. The air around those heatsinks was pretty much completely stagnant.

With the first revision, they finally wised up and put a shroud in, but it only extends up to the front of the heatsinks and doesn't cover them. This most likely pulled air past the heatsink where they were near the shroud, but the far side still wouldn't have had much airflow.

They really just needed a fan blowing on the heatsink. It's the same basic strategy used in most computers. Move a lot of air past the areas of concentrated heat, then use case fans to slowly change the heated case air for fresh cool air. Heats up other components away from the big heat sources a bit more, but dramatically lowers temps for the processor. Either that or use properly designed shrouds that force ALL the intake air for those fans through the whole heatsink. Also, bigger fans so the thing didn't sound like a damn vacuum cleaner wouldn't have hurt.

Comment Re:Cat5 (Score 4, Informative) 399

What are you talking about? The vast majority of Cat 5 is unshielded. On the off chance it does have shielding it's usually foil. The main noise rejection strategy with twisted pair is running a balanced signal, thus the requirement for signal lines in pairs.
Canada

Creating a "Force Field" Invisible Touch Interface 138

angry tapir writes "Using infrared sensors like the ones on television remote controls, Texas A&M University students presented an inexpensive multitouch system at the Computer Human Interaction (CHI) conference in Vancouver. 'I like to consider it an optical force field; it's like a picture frame where we shoot thousands of light beams across and we can detect anything that intersects that frame,' said Jonathan Moeller, a research assistant in the Interface Ecology Lab at Texas A&M University. The frame is lined with 256 IR sensors, which are connected to a computer. When ZeroTouch is mounted over a traditional computer screen it turns the display into a multitouch surface. Taken one step further, if the screen is suspended then a user could paint a virtual canvas."

Comment Re:Disable it (Score 1) 374

Weekly tests are run individually at each station, and are not required to be automatically triggered. Programming should never be interrupted by a weekly test unless the station operator chooses to interrupt programming. At the radio stations I worked at, it was always placed into a regular break specifically to not cause an interruption.

Comment Re:No! It is really, really bad. (Score 1) 2288

-Airlines typically use imperial units for air pressure and speed.

Actually outside the US, it's common to see pressure in millibars. Common enough that text based weather products in the US commonly have both inches of mercury and millibars. If I remember right, the bar isn't an SI unit, but it is based off of the pascal.

As far as speed goes, cruising speed is usually given as a mach number, which is unitless. Slower speeds are commonly given in knots or nautical miles per hour. Despite the name, the international definition of the nautical mile is actually based off the meter (1852m) and yes, even the US uses this definition.

Measuring fuel in pounds and gallons still shows up, although I understand that gauges are just reprogrammed to display kilograms and liters when sold to countries where that would be more appropriate. There isn't really much in aviation that is still truly imperial.

Comment Re:Low oxygen perhaps compensated by speed of desc (Score 1) 327

You'd have to be falling pretty close to the speed of sound to get any appreciable compression effect. Air up to Mach 0.3 is usually treated as incompressible. From 0.3 to 0.7 it becomes more significant, but not nearly enough to do something like double in pressure. The only way to really get a "ram air" style pressure increase is with a supersonic flow.

If my estimations are correct, I highly doubt that at 30,000 feet terminal velocity would be above Mach 0.4. At that speed, pressure increase would almost certainly be in the single digit percentages at most. I'd be surprised if the effect was greater than about 3%.

Comment Re:Because of bad examples (Score 1) 720

How about something not working because you picked two options that conflict with each other? A gui would not allow that.

Why not? There's nothing inherent about a GUI that prevents you from making mistakes. A poorly designed GUI could very well allow you to select conflicting options, and a good one could make it obvious and prevent it.

On the other hand, a program using a text based config could just fail silently, or it could print a useful error message that points you directly to the problem. I'm quite certain you can make configuration from great to shitty and everywhere in between in either a GUI or CLI environment.

Comment Re:Dead on (Score 4, Informative) 720

And when's the last time you edited photos, video, or audio with a CLI?

When I was a sysadmin at a radio station, I wrote scripts that processed audio, including cutting and splicing. Having it automated saved a hell of a lot of time for the people that used to have to sit in front of a GUI and do it.

Of course, there's all kinds of audio work that couldn't be done by script. The point is, you need both kinds, even for audio and video.

Comment Re:So uh (Score 1) 964

Air travel has quite an impressive track record. Nuclear power is still pretty new...

Really??

The first (widely used) jet powered airliner went into flight testing in 1949. The first civilian nuclear power generating station went into service in the Soviet Union in 1954. I'm not sure that extra five years really made that much of a difference in terms of our knowledge of the particular technologies.

Keep in mind that the jet I'm referring to, the de Havilland Comet, killed a lot of people because of various design problems. The initial wing design didn't fare well in a stall, and the engine inlets tended to cause power loss at high pitch angles. Of course they're quite famous for several structural failures caused by metal fatigue. Our relatively poor understanding of how stress and fatigue affected the aircraft skin resulted in a bad design with lots of sharp corners.

I suppose you could argue that we've been flying for much longer than jets have been around, but I think comparing the use of the jet engine in flight with the use of nuclear energy in power generation is a more solid comparison. The jet really enabled air transportation in the form that we know it today. My point is that we were still at some pretty basic stages of learning how to make airplanes safe when nuclear power sprang into being, and a hell of a lot of advancement has been made in both industries since then.

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