Aircraft designers call these Vortex Generators. Their purpose is to disrupt the laminar airflow. This helps the air streams to "stick" to the wing, improving control responsiveness and lowering stall speeds. The difference can be quite noticeable with some airfoil shapes, or almost unmeasurable in others, so one doesn't see them on all aircraft.

But what the article discusses here is NOT a vortex generator or anything of that ilk. It seems to be some sort groove that can mitigate the scratching caused by abrasives in the air stream. It might be interesting to see if such grooves could be integrated with Vortex Generators to improve not only wing performance but also longevity against abrasives, such as a dust or sand storm.

We discovered a nearly omnidirectional horizontally polarized antenna (think about that). It fit on the existing mount and looks pretty much like all the other sticks on the water tower. Hint: it's not really a stick. It's a slotted waveguide. Theory suggests that a vertically polarized signal will drop 20 dB when received with a horizontally polarized antenna and that's pretty much what we measured.

We filed for a license variance from the FCC to switch polarization from Vertical to Horizontal. The FCC engineers were actually impressed with our solution. They had never heard of this antenna before.

We switched master antennas while a series of teams were stationed out in the field to twist the the yagi antennas sideways. It was a significant operation.

Yes, we could have sued someone. But it wouldn't have solved our problems. The fact is that we were all operating legally. The FCC screwed up. Our company attorneys weren't really up to the task of filing a federal lawsuit of that magnitude and the costs were not worth the time and hassle we'd spend to recover the money.

Read the post very carefully. 928.8 is OUTSIDE the ISM band from 902-928 MHz. Yes. It was/is licensed under Part 94.

Missing from the discussion is why this happened to begin with. The Federal Communications Commission was created with the explicit mission to avoid allocation problems like this with the electromagnetic spectrum. This is not the first time they've screwed up like this. In the late 1980s we installed a SCADA sytem on 928.8 MHz. A year after we were up and running, high power paging showed up on 929.03 MHz. You could light a neon bulb with the energy we were getting from our Master receiver antenna.

Our remotes were transmitting with 5 watts and the paging systems were transmitting with over 3 kW ERP. Our receivers had been optimized for sensitivity, not selectivity. But even with the state of the art receivers designed for selectivity, we were still getting clobbered. Only with massive effort did we overcome this problem.

The FCC screwed up because they don't do their homework any more. Even back then, engineers were being relegated to the broom closet while attorneys and political hacks took charge. Applicants were being told to hire consultants to suggest available frequencies, do interference studies and to submit the consultant's work with their license application. Tell me there wasn't a conflict of interest even then!

For all I know things are still like that today. LS probably paid for a consultant who told them what they and the FCC commissioners wanted to hear.

This is why we can't have nice things. We need an FCC to keep this from happening. And instead of an FCC, we get political hacks of both flavors who don't know a damned thing about the state of the art or even what the radio spectrum is.

Parent post is quite correct. The largest cost of a GPS receiver in an aircraft is NOT the electronics itself, but the installation and certification process, not to mention the database updates.

Remember that it has to work with many other transmitters and receivers nearby, including a Mode C or Mode S radar transponder required for most metropolitan regions, a UHF (403 MHz) ELT, a pair of VHF transmitters, possibly an HF SSB radio or an old DME system, and maybe even a weather radar. --and that's just the stuff that is supposed to deliberately transmit. Receivers can radiate their local oscillators...

The bottom line is that when you put safety of flight navigation equipment in an aircraft, it has to be tested and certified before it can be used. Lightsquared would like us to just "replace it" with something new.

I'd like to put their executives in an airliner filled with their damned LTE phones landing on a CAT III approach on a dark and stormy night. We'll see how "rigged" those tests were.

I agree with the sentiments, and I acknowledge that someone will try it. However, others have figured out how easy it is to defeat this Anti-satellite weapons have already been tested and it would be foolish to think that they do not exist in anyone's arsenal. The end result is lots of debris in orbits that may last hundreds of years..

A treaty of this sort would have to acknowledge this problem and put long term concerns over short term tactical needs. The answer is probably the hypersonic scram-jets they're developing right now for the military. These technologies have the potential of being on target perhaps even before an orbital platform can put something there. It has the added advantage that even if shot down, it is unlikely it would leave debris in orbit for long.

Please note that I'm not advocating such weaponry or policies; I'm merely pointing out that this is where the technology is going. I don't think we'll have to be too concerned until we have a significant colony of independent people living in space.

In every case where aviation has been stretching the envelope, there have been accidents and fatalities. The GB Racer is a classic case of this. Many of the renown WWII aircraft had A versions that were anything but safe to fly.

The venerated F-16 wasn't much to write home about either when it was first released. The engineers will learn and get experience. It will come at a horrible price. But if you wanted to live a safe life, you shouldn't be in the military in the first place.

OK, but wouldn't a designer have to compete with those who show their clothes on better looking models?

Using that logic, wouldn't a paint shop have to show their work on a car that is dirty instead of clean?

Note to moderators, the point this AC makes is interesting, please mod up.

So if I understand what you're saying, you feel that you're making connections and getting things done that you couldn't have been able to do if you were dressed like a typical shirtsleeve engineer?

I should point out that I know guys dressed in dirty T-shirts and jeans, two I know even have dreadlocks, who are widely respected and revered. When they speak, the room goes quiet. Conversely, I know some folk who dress very well. As soon as they say something, well, they might as well be dressed in a clown suit.

Are you practicing engineering or IT, or are you managing them? Clearly you feel the clothes make the man, thus I have to ask what impressions you were able to project that you couldn't have done by speaking?

I have repeated this to my kids numerous times: a person can go from good looking to ugly in the time it takes them to open their mouths and say something.

This seems especially alien to girls because every social cue they see on TV and in print seems to scream at them to make good impressions. As such, I really do not know what to make of all the cries of perfect models casting clothes.

What is a fashion designer supposed to do? Show their clothes on physically disgusting people?