Being transmitter agnostic is a problem because various ranging technologies have different implementations. Sure, you could conceivably use information from three VORs to accomplish this, but the accuracy would probably only be good to 1/10 nm. AM radio stations are handy navaids if you know where they are and you have an ADF. I could fly most of the way from Kansas City to Chicago by tuning the ADF to 720kHz. However, this doesn't tell you where you are, and no new aircraft come equipped with an ADF these days. None of this technology can provide the precision or accuracy of GPS. I'm just keeping my fingers crossed for GPS/Galileo/GLONASS receivers.
Nice job installing your own avionics! I should clarify I had a fair bit of help...since my employer manufactures avionics.:)
I'm a pilot, and an engineer who designed some of the equipment in the panel of my aircraft. This idiocy at the FCC scares the crap out of me when you consider the NextGen ATC system the FAA is rolling out. This will lead to loss of situational awareness for pilots and air traffic controllers resulting inevitably in death, just so someone can say OMG i HAVE TEH FOUR GEES.
An aviation panel-mount model? Talk to your avionics shop tech, make sure the software is up to date. And don't listen to the idiots that talk about AGPS and their smartphones, I have far more knowledge than they do about GPS...
Turn off the "highway" and "tolls" avoidances. The GPS isn't magic, if you don't RTFM and verify all the settings, its your own fault if it does something silly like this.
"Your statement about Apple being "the worst" for warranties is about the biggest pile of flaming BS I have seen recently. They're expensive, they're arrogant, they're controlling, etc, but the grand majority of their customers rate the warranty and customer support five star."
Ask anyone who ever owned an iBook, particularly the G3 series. For years, Apple *knowingly* manufactured laptops with mechanical defects that caused the laptops to quickly die due to stress cracks in the BGA solder connections on the GPU. Their solution? As long as you were in warranty, they replaced your failed motherboard with...another defective motherboard. After the peons, er, customers got upset, Apple decided they would extend the warranty period, so after your replacement motherboard failed you could get...another defective motherboard. *NEVER* did they do *ANYTHING* to fix the problem, even in successive hardware revisions. None of these machines will live more than a couple years of regular use unless the owner is proficient with SMT reworking.
Let's look at the Blue and White G3 towers too. Apple managed to screw up using IDE hard drives. They offered some workarounds and partially fixed the problem in later versions, but ultimately, no Blue and White G3 ever could ever run in the IDE modes advertised. Despite many complaints, UDMA flat out doesn't work on this computer. What resoultion was there? Apple has given owners the finger, and never fixed the problem.
Your anecdote of "oh I saw two machines that Apple fixed" does not excuse or cancel out their malfeasance in ignoring millions of computers they knowingly manufactured defectively and refused to stand behind.
I have a hydraulic booster for the brakes on my 6.2 Suburban, which generates no vacuum. The booster is driven by the power steering system. Had GM sized the brakes intelligently (front discs on the Suburban are about the same size as the rear discs on my Volvo) it would be an incredibly effective brake system.
"Do you have a citation for your source on this interference information?"
Myself. I'm the engineer that first saw it, tested it, and determined an immediate resolution of the problem for the aircraft owner, who happened to be a friend and former colleague.
The aircraft more specifically is much like yours, a PA-32R-301. The owner of the aircraft in my story is an aerospace engineer and US Navy pilot. He took a video of the problem in flight. When he arrived to see me he was able to reproduce the problem on the ground. Rerouting the antenna wires to put some more distance between them all helped resolve the issue. The effect of the problem varied on software version and whether or not you had WAAS. A GPS 400 would not exhibit the problem, but that same unit with a WAAS update would. In theory you should be able to make a 530 exhibit this behavior, but if it ain't broke...well, you know. If I hear anymore about this, you'll probably hear more about it in the form of an AD.:p
Oh, and the Ground frequency for our local GA airport is 121.6. We have a lot of airports in the area.
Another example of noise causing problems can be seen in AD 2001-23-17. External electrical noise could cause inaccurate course deviations to be displayed on the CDI or HSI on a GNS 430. RF causes noise.
I believe you're right about the issue being the FCC's and not the FAA's. I can't think of a FAR of the top of my head about cell phones. Ultimately though, the problems I described are due to *any* RF, and you can't predict what gadgets are going to emit.
"Finally, guns are fundamentally rather simple mechanical devices; it's not that hard for someone with a machine shop to make their own."
Yep, its not hard to make one that will blow your hand or face off. Having the knowledge and ability to manufacture something is irrelevant if you don't know how it needs to be made. You can build a bolt action rifle easily enough, sure, but are you going to get the chamber thickness and metals right so it doesn't go kaboom? If you're going to build a semiautomatic weapon, have fun figuring out the timing and safe pressures for operation. A safe firearm is not trivially simple to make.
The AC is absolutely correct. The average commenter on this thread really doesn't understand E&M.
Every radio antenna has a defined radiation pattern. Cell phone towers incorporate directional antennas and have very focused radiation patterns to extend the horizontal range of the tower. If the tower were radiating vertically into the sky, it would be wasted power, and the ground range of the tower would be reduced.
Since the strength of a radio signal decreases with the square of its distance from the transmitter, and neglecting the information I gave about radiation patterns with respect to directional antennas, a cell phone radio one *foot* from a wire on an airplane poses a greater risk of interference than its transmitter one *mile* away, despite the fact that the transmitter is a couple orders of magnitude more powerful than the phone.
However, here's the best story:
A Piper PA-32R aircraft equipped with a GNS-430W was reporting loss of GPS fix when the VHF comm was in use on certain frequencies. The VHF antenna is on the bottom of the fuselage, and the GPS antennas are located on the top. It was determined that the frequencies this occurred on were were between 121.0 and 122.0 MHz. This is nowhere near GPS frequencies, which are at 1.57 and 1.23 GHz. So what causes a complete loss of fix when the VHF transmits? The ELT (emergency location transponder) transmits at 121.5MHz. The ELT is off in flight and only activated when an aircraft crashes, or manually by a pilot in distress. The VHF comm transmissions *near* 121.5 energized the ELT's transmitter, which had a wire running very near the GPS antenna wires. The resultant interference on the GPS antenna wires caused the avionics to lose the fix. For a pilot shooting a GPS/WAAS approach in IMC, activating the comm would cause GPS failure, and force the pilot to execute a missed approach. Ultimately, this could make safely landing the aircraft at an airport impossible.
So if someone were to ask me if I thought a cell phone had the potential to interfere with avionics, I would say yes, and I would back it up with experimental evidence backed by hard physics. And if they wanted to keep challenging the concept, I would politely remind them that I toiled for years to become an aerospace engineer and a pilot, and have spent many years in the aerospace and consumer electronics industries. Unless someone has a credible basis of knowledge and experience in these fields, their arguments on this topic usually are without merit.
We do it, a major publicly traded international company with thousands of employees. Its not hard: make/etc a repository (we like mercurial), have puppet manage your servers, and revision control the server config files on the puppetmaster (again, mercurial helps here).
I work at an aerospace and consumer electronics company. The junk in the 1 ft^3 scrap bins is worth thousands of dollars on the street. Over the course of several months I built a "museum display" at my desk showing the evolution of one of our product lines by building 20 of them in fully operational condition out of scrap. The street price of the "museum" is about $12,000, so yeah, I believe this guy could have stolen $1M from EMC.
I was having a conversation with a few of my friends (one of which brought one of his friends with) about the last time we had gone to the shooting range together (an activity I enjoy). Apparently the new guy got got upset and started going off on how my hobby was stupid, guns should be outlawed, he doesn't understand why the 2nd Amendment exists, etc. People have a right to their opinions, ok. But in an attempt to justify himself, his last sentence sent chills down my spine and left an awkward silence in the room: "This country wasn't founded on violence."
I have a decked out D630 running Fedora for work, and it was one of the last to go out before we switched to E6xxx machines. The D630 is arguably the most well-rounded and reliable laptop I've ever had. The E6xxx laptops though we have had tons of problems with. Very few D630s actually went out, we had mostly D620s. People with older and newer machines here stare jealously at my D630, but they know the only way to get it is from my cold, dead hands.
I own an interesting relic of GM's past, an original 1983 Chevrolet Suburban C10 6.2L in very good condition. This monstrous vehicle is powered by the engine that was destined for glory as the powerplant for the HMMWV. Its not the most powerful thing around, but if I'm leadfooted around town I'll get 16mpg, and on the highway cruising at 70mph, 23mpg. Not bad considering it weighs 6000 lbs. and has the aerodynamics of a barn. Since it has a 40 gal tank, I can theoretically go 800 miles on a single fillup. Typically I go 500 miles because the fuel gauge isn't accurate below 1/4 tank.
There's a station that sells biodiesel at the pump where I live, and I can get up to B50 there. I notice no loss of performance or economy on B50.
You wouldn't believe the number of people, complete strangers, who see this thing and ask where I found it, and how much I would sell it to them for. Its predictable, reliable, relatively easy to maintain, and could outlive me.
100 year old Diesel technology is more helpful in our current situation than wasting money trying to conjure up new fuels from nothing. Here's a couple vehicles I have that provide a better solution:
1984 Mercedes 300SD Turbo (OM617): It will run on just about anything. All kinds of oils, both vegetable and petroleum, jet fuel, heck, you can even dump ATF in the tank (though I don't recommend it) and it will burn that.
1983 Chevrolet Suburban (Detroit Diesel/Allison 6.2): This will also run on just about anything. It has the engine that AM General picked to power the HMMWV. There are probably still lots of these 6.2s running around all corners of the earth powered by who knows what.
These vehicles are likely going to still be puttering around for a very, very long time. Rust will get them before the engines go. We need to be focusing on developing better engines so that we don't end up backed into a corner on fuel. If we truly have options on what we can power our vehicles with, we'll be in a much better position.
I have. Its better than gitosis, but not good enough to really make large businesses notice.
We use Gerrit and contribute back improvements and fixes since we get the functionality we need and the developer time in fixing Gerrit is less than the cost of buying commercial SCM software.
Have you ever tried to administer a central hg or git code repository accessed by a couple thousand developers and maintain access controls on it, like you would in a corporate environment? I have, its a complete pain.
The distributed nature of a tool like git is nice in that you don't have locking and its easy to get all the code you need. However, its worthless to a company unless that can be managed, and you realistically need something like Gerrit (git code review, access control system) or github:fi (costs a metric crapload to help Scott Chacon buy a fleet of Ferraris).
I can log in as root to the GPS I have in my car. Then again, I wrote a bunch of the software for it for my job...at a company that makes GPSs for cars...
I am an aerospace engineer and have worked with equipment from domestic (American) companies and Chinese companies. I designed a special type of wind tunnel test stand and equipped two, one with a 6DOF strain gage sting balance from Lockheed Martin, and another with a 6DOF strain gage sting balance from China Aerodynamic Research and Development Center.
The CARDC balance had all the gages and wiring on the exterior of the balance. There were over 40 strain gages on a device about 6 inches long, which meant tiny wires were glued all over the outside of the balance. This meant that the device was subject to damage from even the most gentle handling, and even damage from normal use in a wind tunnel. I was supplied with calibration data that was completely wrong, and the nonlinear differential equations that defined each degree of freedom didn't provide results that corresponded with the output of the device. I had to build a calibration stand and completely recalibrate the device and come up with new equations. The price tag for this piece of crap? $100,000.
The Lockheed balance was designed so all wiring and gages were *inside* the structure. This meant that the extremely delicate wires and gages could not be damaged by handling the balance, and they would resist damage from use. The calibration provided by Lockheed was correct, and they were able to provide data on the device dating back to when Chance-Vought built it. I never had a problem with the Lockheed balance. Price? The same as the Chinese one.
Next up is design practice. I know what design processes are used in Chinese aerospace companies. How do I know? Because they bought the design books from my old company, and then copied them and passed them around. They also decided to use an old cracked version of our aircraft design software. People who actually bought the software got updates and bugfixes. These clowns do not.
This was just a few years ago. I was trained by and worked for the most influential aircraft designer in the world. Having dealt with Chinese aerospace companies and seen first hand their lack of engineering acuity, there's no way you'll get me to step foot on one of their aircraft.
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Being transmitter agnostic is a problem because various ranging technologies have different implementations. Sure, you could conceivably use information from three VORs to accomplish this, but the accuracy would probably only be good to 1/10 nm. AM radio stations are handy navaids if you know where they are and you have an ADF. I could fly most of the way from Kansas City to Chicago by tuning the ADF to 720kHz. However, this doesn't tell you where you are, and no new aircraft come equipped with an ADF these days. None of this technology can provide the precision or accuracy of GPS. I'm just keeping my fingers crossed for GPS/Galileo/GLONASS receivers.
Nice job installing your own avionics! I should clarify I had a fair bit of help...since my employer manufactures avionics. :)
I'm a pilot, and an engineer who designed some of the equipment in the panel of my aircraft. This idiocy at the FCC scares the crap out of me when you consider the NextGen ATC system the FAA is rolling out. This will lead to loss of situational awareness for pilots and air traffic controllers resulting inevitably in death, just so someone can say OMG i HAVE TEH FOUR GEES.
The industry report is real and true, I know several of the authors, one of them works down the hall from me.
An aviation panel-mount model? Talk to your avionics shop tech, make sure the software is up to date. And don't listen to the idiots that talk about AGPS and their smartphones, I have far more knowledge than they do about GPS...
Turn off the "highway" and "tolls" avoidances. The GPS isn't magic, if you don't RTFM and verify all the settings, its your own fault if it does something silly like this.
You haven't looked too deep, have you?
"Your statement about Apple being "the worst" for warranties is about the biggest pile of flaming BS I have seen recently. They're expensive, they're arrogant, they're controlling, etc, but the grand majority of their customers rate the warranty and customer support five star."
Ask anyone who ever owned an iBook, particularly the G3 series. For years, Apple *knowingly* manufactured laptops with mechanical defects that caused the laptops to quickly die due to stress cracks in the BGA solder connections on the GPU. Their solution? As long as you were in warranty, they replaced your failed motherboard with...another defective motherboard. After the peons, er, customers got upset, Apple decided they would extend the warranty period, so after your replacement motherboard failed you could get...another defective motherboard. *NEVER* did they do *ANYTHING* to fix the problem, even in successive hardware revisions. None of these machines will live more than a couple years of regular use unless the owner is proficient with SMT reworking.
Let's look at the Blue and White G3 towers too. Apple managed to screw up using IDE hard drives. They offered some workarounds and partially fixed the problem in later versions, but ultimately, no Blue and White G3 ever could ever run in the IDE modes advertised. Despite many complaints, UDMA flat out doesn't work on this computer. What resoultion was there? Apple has given owners the finger, and never fixed the problem.
Your anecdote of "oh I saw two machines that Apple fixed" does not excuse or cancel out their malfeasance in ignoring millions of computers they knowingly manufactured defectively and refused to stand behind.
I have a hydraulic booster for the brakes on my 6.2 Suburban, which generates no vacuum. The booster is driven by the power steering system. Had GM sized the brakes intelligently (front discs on the Suburban are about the same size as the rear discs on my Volvo) it would be an incredibly effective brake system.
"Do you have a citation for your source on this interference information?"
Myself. I'm the engineer that first saw it, tested it, and determined an immediate resolution of the problem for the aircraft owner, who happened to be a friend and former colleague.
The aircraft more specifically is much like yours, a PA-32R-301. The owner of the aircraft in my story is an aerospace engineer and US Navy pilot. He took a video of the problem in flight. When he arrived to see me he was able to reproduce the problem on the ground. Rerouting the antenna wires to put some more distance between them all helped resolve the issue. The effect of the problem varied on software version and whether or not you had WAAS. A GPS 400 would not exhibit the problem, but that same unit with a WAAS update would. In theory you should be able to make a 530 exhibit this behavior, but if it ain't broke...well, you know. If I hear anymore about this, you'll probably hear more about it in the form of an AD. :p
Oh, and the Ground frequency for our local GA airport is 121.6. We have a lot of airports in the area.
Another example of noise causing problems can be seen in AD 2001-23-17. External electrical noise could cause inaccurate course deviations to be displayed on the CDI or HSI on a GNS 430. RF causes noise.
I believe you're right about the issue being the FCC's and not the FAA's. I can't think of a FAR of the top of my head about cell phones. Ultimately though, the problems I described are due to *any* RF, and you can't predict what gadgets are going to emit.
"Finally, guns are fundamentally rather simple mechanical devices; it's not that hard for someone with a machine shop to make their own."
Yep, its not hard to make one that will blow your hand or face off. Having the knowledge and ability to manufacture something is irrelevant if you don't know how it needs to be made. You can build a bolt action rifle easily enough, sure, but are you going to get the chamber thickness and metals right so it doesn't go kaboom? If you're going to build a semiautomatic weapon, have fun figuring out the timing and safe pressures for operation. A safe firearm is not trivially simple to make.
There was just an NCIS episode about this!
The AC is absolutely correct. The average commenter on this thread really doesn't understand E&M.
Every radio antenna has a defined radiation pattern. Cell phone towers incorporate directional antennas and have very focused radiation patterns to extend the horizontal range of the tower. If the tower were radiating vertically into the sky, it would be wasted power, and the ground range of the tower would be reduced.
Since the strength of a radio signal decreases with the square of its distance from the transmitter, and neglecting the information I gave about radiation patterns with respect to directional antennas, a cell phone radio one *foot* from a wire on an airplane poses a greater risk of interference than its transmitter one *mile* away, despite the fact that the transmitter is a couple orders of magnitude more powerful than the phone.
However, here's the best story:
A Piper PA-32R aircraft equipped with a GNS-430W was reporting loss of GPS fix when the VHF comm was in use on certain frequencies. The VHF antenna is on the bottom of the fuselage, and the GPS antennas are located on the top. It was determined that the frequencies this occurred on were were between 121.0 and 122.0 MHz. This is nowhere near GPS frequencies, which are at 1.57 and 1.23 GHz. So what causes a complete loss of fix when the VHF transmits? The ELT (emergency location transponder) transmits at 121.5MHz. The ELT is off in flight and only activated when an aircraft crashes, or manually by a pilot in distress. The VHF comm transmissions *near* 121.5 energized the ELT's transmitter, which had a wire running very near the GPS antenna wires. The resultant interference on the GPS antenna wires caused the avionics to lose the fix. For a pilot shooting a GPS/WAAS approach in IMC, activating the comm would cause GPS failure, and force the pilot to execute a missed approach. Ultimately, this could make safely landing the aircraft at an airport impossible.
So if someone were to ask me if I thought a cell phone had the potential to interfere with avionics, I would say yes, and I would back it up with experimental evidence backed by hard physics. And if they wanted to keep challenging the concept, I would politely remind them that I toiled for years to become an aerospace engineer and a pilot, and have spent many years in the aerospace and consumer electronics industries. Unless someone has a credible basis of knowledge and experience in these fields, their arguments on this topic usually are without merit.
Actually, your sentence should have been longer, specifically, by just one letter: a.
"SPARC T-series (fast, but only for throughput-driven workloads; expensive; fairly power-hungry)"
Power hungry? They were marketed as super low power chips. I'm pretty sure there wasn't even a fan on my 8-core UltraSPARC T1.
FTFY.
Such pedantry reminds me that THIS IS SLASHDOOOTTTTTT, but then I remember we're talking about the wrong part of Greece: Rhodes, not Sparta.
We do it, a major publicly traded international company with thousands of employees. Its not hard: make /etc a repository (we like mercurial), have puppet manage your servers, and revision control the server config files on the puppetmaster (again, mercurial helps here).
I work at an aerospace and consumer electronics company. The junk in the 1 ft^3 scrap bins is worth thousands of dollars on the street. Over the course of several months I built a "museum display" at my desk showing the evolution of one of our product lines by building 20 of them in fully operational condition out of scrap. The street price of the "museum" is about $12,000, so yeah, I believe this guy could have stolen $1M from EMC.
I was having a conversation with a few of my friends (one of which brought one of his friends with) about the last time we had gone to the shooting range together (an activity I enjoy). Apparently the new guy got got upset and started going off on how my hobby was stupid, guns should be outlawed, he doesn't understand why the 2nd Amendment exists, etc. People have a right to their opinions, ok. But in an attempt to justify himself, his last sentence sent chills down my spine and left an awkward silence in the room: "This country wasn't founded on violence."
I have a decked out D630 running Fedora for work, and it was one of the last to go out before we switched to E6xxx machines. The D630 is arguably the most well-rounded and reliable laptop I've ever had. The E6xxx laptops though we have had tons of problems with. Very few D630s actually went out, we had mostly D620s. People with older and newer machines here stare jealously at my D630, but they know the only way to get it is from my cold, dead hands.
Agreed, the E6xxx series is horrible.
I own an interesting relic of GM's past, an original 1983 Chevrolet Suburban C10 6.2L in very good condition. This monstrous vehicle is powered by the engine that was destined for glory as the powerplant for the HMMWV. Its not the most powerful thing around, but if I'm leadfooted around town I'll get 16mpg, and on the highway cruising at 70mph, 23mpg. Not bad considering it weighs 6000 lbs. and has the aerodynamics of a barn. Since it has a 40 gal tank, I can theoretically go 800 miles on a single fillup. Typically I go 500 miles because the fuel gauge isn't accurate below 1/4 tank.
There's a station that sells biodiesel at the pump where I live, and I can get up to B50 there. I notice no loss of performance or economy on B50.
You wouldn't believe the number of people, complete strangers, who see this thing and ask where I found it, and how much I would sell it to them for. Its predictable, reliable, relatively easy to maintain, and could outlive me.
100 year old Diesel technology is more helpful in our current situation than wasting money trying to conjure up new fuels from nothing. Here's a couple vehicles I have that provide a better solution:
1984 Mercedes 300SD Turbo (OM617): It will run on just about anything. All kinds of oils, both vegetable and petroleum, jet fuel, heck, you can even dump ATF in the tank (though I don't recommend it) and it will burn that.
1983 Chevrolet Suburban (Detroit Diesel/Allison 6.2): This will also run on just about anything. It has the engine that AM General picked to power the HMMWV. There are probably still lots of these 6.2s running around all corners of the earth powered by who knows what.
These vehicles are likely going to still be puttering around for a very, very long time. Rust will get them before the engines go. We need to be focusing on developing better engines so that we don't end up backed into a corner on fuel. If we truly have options on what we can power our vehicles with, we'll be in a much better position.
I have. Its better than gitosis, but not good enough to really make large businesses notice.
We use Gerrit and contribute back improvements and fixes since we get the functionality we need and the developer time in fixing Gerrit is less than the cost of buying commercial SCM software.
Mod parent up.
Have you ever tried to administer a central hg or git code repository accessed by a couple thousand developers and maintain access controls on it, like you would in a corporate environment? I have, its a complete pain.
The distributed nature of a tool like git is nice in that you don't have locking and its easy to get all the code you need. However, its worthless to a company unless that can be managed, and you realistically need something like Gerrit (git code review, access control system) or github:fi (costs a metric crapload to help Scott Chacon buy a fleet of Ferraris).
"How about the GPS unit in your car?"
I can log in as root to the GPS I have in my car. Then again, I wrote a bunch of the software for it for my job...at a company that makes GPSs for cars...
I am an aerospace engineer and have worked with equipment from domestic (American) companies and Chinese companies. I designed a special type of wind tunnel test stand and equipped two, one with a 6DOF strain gage sting balance from Lockheed Martin, and another with a 6DOF strain gage sting balance from China Aerodynamic Research and Development Center.
The CARDC balance had all the gages and wiring on the exterior of the balance. There were over 40 strain gages on a device about 6 inches long, which meant tiny wires were glued all over the outside of the balance. This meant that the device was subject to damage from even the most gentle handling, and even damage from normal use in a wind tunnel. I was supplied with calibration data that was completely wrong, and the nonlinear differential equations that defined each degree of freedom didn't provide results that corresponded with the output of the device. I had to build a calibration stand and completely recalibrate the device and come up with new equations. The price tag for this piece of crap? $100,000.
The Lockheed balance was designed so all wiring and gages were *inside* the structure. This meant that the extremely delicate wires and gages could not be damaged by handling the balance, and they would resist damage from use. The calibration provided by Lockheed was correct, and they were able to provide data on the device dating back to when Chance-Vought built it. I never had a problem with the Lockheed balance. Price? The same as the Chinese one.
Next up is design practice. I know what design processes are used in Chinese aerospace companies. How do I know? Because they bought the design books from my old company, and then copied them and passed them around. They also decided to use an old cracked version of our aircraft design software. People who actually bought the software got updates and bugfixes. These clowns do not.
This was just a few years ago. I was trained by and worked for the most influential aircraft designer in the world. Having dealt with Chinese aerospace companies and seen first hand their lack of engineering acuity, there's no way you'll get me to step foot on one of their aircraft.