EricJ

All spoofing does is make the GPS indicate that it's in some position other than what it is actually in. That can be done independently of where it is or what direction it is headed in or how fast it is going. As a simple example, if you send it the same signal it would see if it was in Hawaii while it's in Iowa, it'll indicate that it's in Hawaii. What the signal should look like to a receiver at any given time in any given location is a solvable problem, and that's basically what is done to spoof a receiver. If you have an independent means to track a drone that you're attacking, say, with a radar, you can drive the GPS spoofing signal using the feedback from the tracking method to steer it, especially if you know where it was intending to go. As I mentioned, there is a fair amount of literature out there on the topic. It is not a new thing, it's been demonstrated and studied for some time now. It isn't a trivial thing to do, but it is doable, and has been done.

The input to the GPS system from the satellite constellation is a single antenna, so the receiver has no way to determine whether the input signal is actually from multiple satellites or an accurately reproduced signal from a single source. The antennas aren't very directive, since they need to be able to see from nearly horizon to horizon, and it is not difficult to overcome the satellite signal level if one were intent to do so, even from the ground. If something like a drone is using GPS to navigate, an attacker on the ground can manipulate the drone into navigating where the attacker desires. There are a number of fairly in-depth forensic articles on what likely happened to the RQ-170 drone, and it's very practical. The Iranians were very clever about it. The first article I linked also cited some other spoofing demonstrations including one from the radio navigation lab at UT Austin, but it has been demonstrated many times. The guy from UT Austin gave a TED talk on the topic. The last third or so has to do with spoofing. There isn't a lot of detail given, naturally, but more detail is available via searching.

One other thing might be mic connections from the audio panel to the errant comm unit.

Can you be heard through a different comm? If so, then it's not your mic or jack and probably not the audio panel. If you can receive okay on that comm, then it's unlikely to be the antenna or cable or their connections. Sounds like maybe the power amp in that comm unit has failed.

Just to add a little bit, spoofing GPS has been done very effectively. The Iranians have gotten pretty good at it: https://sofrep.com/46818/gps-spoofing-how-iran-tricked-us-patrol-boats-into-capture/ https://en.wikipedia.org/wiki/Iran–U.S._RQ-170_incident

There are multiple navigation satellite systems, but they all have global coverage and are all Global Navigation Satellite Systems (GNSS). The US deployed GPS, the Russians deployed GLONASS, the Europeans deployed Galileo, and the Chinese are deploying Beidou. Why does everybody need one? For defense/security reasons no large power wants to be dependent on somebody else's system, since those somebodies could conceivably turn their system off (or deny it to other others via scrambling, etc.) to disadvantage you in a conflict. GPS used to have Selective Availability, where they could turn accuracy way down for everybody but the military users, but that was abandoned a long time ago due to practical reasons. Some receivers can simultaneously receive and process and navigate from multiple GNSS systems, (e.g., GPS and Galileo), but it is sometimes difficult to find out such details from manufacturers. As more chipsets integrate multiple systems it will likely become more common. Some systems have better theoretical performance limits than others, too (Galileo is better than GPS, partly because it was designed later). The bottom line is that whatever system you are using, it will work globally.

The "Happy Birthday" song has only been public domain for a little while, and only after lengthy litigation. http://www.hollywoodreporter.com/thr-esq/warner-music-pays-14-million-863120 Even when you think you have a copyright, you may not.

Get one of these (pulse oximeter), take it with you and use it frequently. They're simple to use and give a measurement display pretty quickly. https://www.amazon.com/Santamedical-Generation-SM-165-Fingertip-Saturation/dp/B00R59OTOC/ref=sr_1_1?ie=UTF8&qid=1497978930&sr=8-1-spons&keywords=pulse+oximeter&psc=1&smid=A8YXBQ7YB5YFQ Everybody is different, so you need to find out your personal tolerance for it. I take trips occasionally with a buddy that is about the same age as I am (50s), generally same level of health, mobility, etc. I've never smoked in my life, and he was a serious smoker up to a few years ago. On a recent trip cruising at 9500 without O2 he was still showing mid-90s-percent O2 saturation and I was getting down into the 80s...I did get a little bit light-headed. Some people can stay up there with no trouble, others not so much. Using a pulse oximeter is a good, objective way to know how you're doing. Even if you feel okay, if the oximeter says otherwise it's best to go down a bit if you can.

The other side of that is the ethics and morality of claiming ownership of something that other people have already done, or just putting a tiny tweak or difference on something and then claiming ownership. These sorts of things happen in all creative areas including music, art, design, technology (it's a common thing in utility patent infringement). I think it boils down to the usual thing, "My side has the moral high ground and yours does not." Both sides have that point of view. Always.

Hmmm...the only thing I can find is on one of the example drawings it says, "Reproduction of this scheme on another aircraft requires written permission of Scheme Designers, Inc." Sounds to me like their intent is to retain whatever copyrights they may have right to. I don't think they'd have rights to schemes that aren't original to them. EVEN FURTHER DISCLAIMER: I am generally not be listened to for any reason whatsoever.

I think a relevant question that some might want to clear up is whether the Scheme Designers customer agreement gives the customer any copyright ownership. I wouldn't assume that they do. Generally the copyright for commissioned art stays with the artist, not the commissioner or person who paid for it. The person who paid for it may own the particular instance (the canvas or, in this case, the airplane), but I think usually the artist typically retains ownership of the expression, i.e., the image or scheme. If you buy a canvas with an oil painting on it, you own that painting, but the artist may retain the copyright to the image. The artist may retain the right to reproduce copies or license copies, the buyer just owns the particular canvas. If something else is desired one would be wise to negotiate that ahead of time and get it in writing. So my (non-lawyer) expectation would be that if anyone would have claim to the copyright it might likely be Scheme Designers, but that may depend on the wording in whatever contract or agreement they use with their customers. Even so, their claim could easily be challenged by whoever originated the earliest version of that general scheme, whether that would be the factory or somebody else. Who would prevail would not be known until/unless it actually went to court, in my view. "It's not a patent until a judge says it's a patent." A web search on "commissioned art copyright ownership" or something similar might provide some more detailed guidance, or, as the case may be, muddy the waters a bit further. FURTHER DISCLAIMER: I am not a lawyer, an IA, an A&P, a CFI, or somebody anybody with much sense should be taking advice from at any time on any topic. Your mileage may vary. Contents may have settled during shipping.

Even though I am most definitely Not A Lawyer, I've spent much of my career dealing with Intellectual Property including patents, copyright, and trademarks (mostly technology-related utility patents, though). When I worked for a Large Household Name technology company for many years on an internal patent committee our patent lawyers would often say, "It's not a patent until a judge says it's a patent." While somebody might rightly claim a copyright on something like a paint scheme, my personal (non-lawyer) opinion is that it'd be difficult to argue for it in a court when there is a lot of similar prior art. Even if the case was won, I'd think the cost to litigate it would not likely be worthwhile in such a small market. In a case like this where the claimed scheme is so similar to a factory scheme, one might find oneself having to defend a claimed copyright against a factory with similar prior art, and the factory may have deeper pockets and more reason to defend their claim in court than a smaller, aftermarket business. So it sounds to me like anybody who would wade into those waters making an infringement claim would have a pretty uphill battle with some significant downside risk. That can of worms might better be left unopened, to my non-lawyer thinking. But stuff like this happens all the time and there is never a shortage of people trying to make claims on stuff that may not be very defensible. Case in point in recent news: http://www.blabbermouth.net/news/gene-simmons-seeks-to-register-trademark-on-devils-horns-rock-hand-gesture/ Simmons often tries to make claims on stuff that he may not have originated, but maybe his real goal is just to get media time. It usually works. Or maybe he really needs the money. Who knows? On the other hand: http://www.chron.com/news/houston-texas/texas/article/Devil-Horns-Hook-Em-University-of-Texas-KISS-11225169.php So, clear as mud. This is often the case with Intellectual Property and I think the paint scheme thing is no different. Anybody who really wants to assert an intellectual property claim should carefully consider the opinion of relevant legal counsel. Anybody worried about a claim against them shouldn't worry until such a claim is actually made, and, IMHO, even then maybe not so much. Disclaimer: Not a lawyer, not an A&P, not a CFI, totally irrelevant and should never be taken seriously or listened to at any time on any topic whatsoever.

GPS satellites typically have examples of both Cesium and Rubidium references for time standards. Laboratories or other terrestrial places that need accurate time standards often have their own Rubidium standards, but these days a GPS-disciplined source (i.e., a relatively inexpensive source that leverages the atomic-standard reference in the GPS signal), suffices. So, yeah, a wristwatch with a GPS receiver can be, potentially, as accurate as you may get. In the US a watch that can occasionally listen to the WVVB signal from NIST in Ft. Collins can also do reasonably well, which I think is what the "Radio Controlled" clocks like that Citizen uses. The NIST reference that drives the WVVB signal is, I think these days, based on multiple Cesium references.

FWIW, this is a common thing in engineering and programming and is often referred to as an "off by one error" and sometimes the "fence post problem". The latter being a reference to how many fence posts do you need to build ten sections of fence? You need 11. It's an example of a common "off by one error". They happen all the time because, like the time zone thing, the logic isn't always obvious and the pitfalls plentiful. I think what we have learned, however, is that he's a long ways from home.

Whatever type of airplane that was, I'm impressed that it's torn up everywhere but the cabin is intact.

I've known guys that had girlfriends like that.

This is a pet peeve of mine as well, especially on rentals. The Arrow I rent has somebody that frequently does an extreme tightening of the dipstick. Fortunately they keep a pair of pliers in the airplane, which a few times has been the only way we could get the dipstick out. There's no reason for that and, as you say, it increases the chances of the tube unscrewing at the bottom.

My thought was just that ADS-B offers the opportunity to fill in all the low-level areas that are shadowed in a regular radar system. If you're worried about shadows, radar has *WAY* more than ADS-B will ever have, because one of the things ADS-B is designed to do is fill in all of the low-level radar shadows (which are substantial). So I think it is correct to say that if you're worried about ADS-B shadows you should be terrified of radar shadows.

That's not a good sign. There's no reason to not see the logs either before inspection or at initial inspection.

I've been using ADS-B-in via a Stratux with FltPln on my tablet since about January or so. I posted in another thread that while I was still getting used to it I had a near miss with head-on traffic that the tablet was alerting to. Traffic alerts plus in-flight weather data availability is something that once you get used to using you will feel naked without it. The ADS-B system design is light years ahead of using traditional radar systems. Anybody who is worried about shadowing with ADS-B stations should be terrified of relying on controllers using radar. I'm looking forward to the day when the system is fully rolled out. I suspect we'll all wonder how we managed to survive the days when controllers depended on radar and altitude reporting transponders.

Very nice looking airplane! Nicely equipped, too. What are they asking for it?

Not sure if this has been covered, but Delta was opposed to privatizing as of Feb, 2016: http://news.delta.com/delta-study-privatizing-air-traffic-control-will-increase-costs-travelers I don't know whether that has changed in the latest round.

Interesting I learned to fly at Ludwigsburg AAF, which was EDIR but is now Pattonville Airport, EDTQ. We would occasionally visit some of the local glider fields, like Malmsheim, but I don't remember Hornberg and couldn't find it on my old sectional (from 1976).

I'm waiting for somebody on the continent to say that was a hundred-dollar hamburger run.

I think I was #8 on the list a week or so ago, but she said a bunch just came open as a result of some of the work getting done. I got on the list at the end of January. I've no idea what the expectations are going forward, but the shelter you have should make the wait pretty easy, I'd think.