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  #31  
Old 10-23-2016, 09:58 AM
hpmicrowave's Avatar
hpmicrowave hpmicrowave is offline
 
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Default AF News GPS (without WAAS) provides 38 CM(14.9 inch) Accuracy

The NAVWORX certified units can use an external certified GPS source like a G430W Nav unit (SW Ver 5.0 or later). But give me a break, the AF said last April the GPS satellites are providing 15" accuracy without the FAA WAAS signal (see below). The WAAS signal increases accuracy to a few centimeters. So what is the FAA all bent out of shape over? This is Govt Bureaucracy at its Peak. Their begging the aviation community to equip with ADSB, and were fighting over likely the width of your hand in distance. It has been reported that modern GPS units like what is in the "non-certified" but demonstrated compliant NAVWORX WAAS GPS units have better processors and position algorithms than the now ~15 year old "certified" units. So it looks like the direction were on will take us all back in time, force us to downgrade to a FAA certified GPS source which of course will significantly increase cost.

Cecil

SCHRIEVER AIR FORCE BASE, Colo. (AFNS) -- On April 25 2016, the Air Force?s GPS registered its most accurate signal yet, according to the Aerospace Corporation, which has been monitoring the data since 2002.

Using the numbers from a network of NASA-owned, Jet Propulsion Laboratory-operated GPS tracking stations, Aerospace analysts calculated the signal-in-space accuracy of GPS to 38 centimeters (14.9 inches).

?The GPS team works around the clock to ensure we produce the most accurate signal available for our worldwide users,? said Lt. Col. Todd Benson, the 2nd Space Operations Squadron commander.

The squadron performs the command and control mission for the GPS satellite constellation, the world?s premier space-based position, navigation and timing system, capable of providing information to users worldwide.

According to Benson, the new record may be attributed to multiple improvements across the GPS enterprise.

?One improvement has been the outstanding GPS Block IIF spacecraft that have been acquired by the Space and Missile Systems Center and launched by the 45th Space Wing,? he explained. ?These 12 new satellites have enhanced the overall accuracy of the GPS constellation. Combine this with the retirement of older spacecraft, the rock solid performance of the previous block of satellites, and you have the opportunity to improve accuracy.?

He said another reason for the improvement has been the innovative approaches to operating the GPS mission.

?With the help of our engineers and contractor support, we were able to transition to a more stable frequency standard on a satellite to improve overall performance,? Benson said. ?Traditionally, this effort would have only happened if the original component failed. Our ethos is honed to maximize performance while maintaining a robust constellation."

Benson highlighted the GPS?s importance and why its accuracy is beneficial to its 3 billion users.

"GPS is embedded in almost every facet of modern life. From the swipe of a credit card to flying an aircraft around the globe, GPS enhances humanity's day-to-day activities," the colonel said.

PJ Mendicki, the Aerospace senior project engineer who calculated the record accuracy, echoed the sentiment. He stressed that the GPS has been the gold standard for Global Navigation Satellite System applications.

?The fact that GPS accuracy is continually exceeding the promises made in the 2008 Standard Positioning Service Performance Standard proves our nation's commitment to that standard,? he said. ?Through metrics like user range error, we can easily demonstrate that the nation's investment in this technology continues to pay dividends to all humanity, even though most are unaware of how pivotal GPS is to their daily life.?

(Some information compiled from Aerospace news release)
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  #32  
Old 10-23-2016, 10:46 AM
BobTurner BobTurner is offline
 
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Note the "signal in space" phrase. Here on earth the signal must pass thru the ionosphere, where it does not travel at the speed of light in vacuum. This is where you need the waas correction.
There's also some averaging involved. Easy if you're not moving, a lot harder if you are.
But the bottom line is the FAA expanded the mission to include ground ops. That's where the very high positional accuracy is needed, not in flight.
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  #33  
Old 10-23-2016, 10:59 AM
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Radomir Radomir is offline
 
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Default

"integrity" (the I in SIL) and "accuracy" should not be confused to mean the same thing... they are not.

"SIL specifies the probability of the actual position lying outside that containment radius without indication"
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  #34  
Old 10-23-2016, 01:00 PM
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Default our rights on a proposed AD

Going back a few decades of flying, I can't help but remember Bob Hoover. When F. Lee Bailey decided to defend him... I thought "game over for the FAA". After a protracted battle, he won. Then became uninsurable.. so his airshow days were over anyway. The two men responsible for trashing one of the finest pilots in history cruised away quietly to retirement. In the Navworx proposed AD, there are two names and addresses given at the Ft. Worth ACO (Aircraft Certification Office) They hold tremendous power in the industry and operate under their own local judgement. There is no level playing field. That is why we have synthetic vision now. It went through the Anchorage ACO. Had it been in Ft. Worth, we probably would still be mired in research. Same could be said for Seattle.
The point here is this: We have names now. We have addresses now. They are out in the public domain. If you choose to give your concerns to the FAA, for hampering affordable ADS-B or. on the other hand, if you wish to applaud them for keeping you safer, you can and should write. We should hold our public employees accountable for their actions. We pay the bills and we use the airspace. Kyle Cobble and Michael Heusser. Addresses on are on the AD announcement.
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  #35  
Old 10-23-2016, 01:09 PM
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az_gila az_gila is offline
 
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Interesting, the two names you give are in the "Rotorcraft Directorate", not avionics...

https://directory.faa.gov/appsPub/Na...penAgent&10E4E

https://directory.faa.gov/appsPub/Na...penAgent&25B46
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  #36  
Old 10-23-2016, 02:52 PM
David-aviator David-aviator is offline
 
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Quote:
Originally Posted by BobTurner View Post
Note the "signal in space" phrase. Here on earth the signal must pass thru the ionosphere, where it does not travel at the speed of light in vacuum. This is where you need the waas correction.
There's also some averaging involved. Easy if you're not moving, a lot harder if you are.
But the bottom line is the FAA expanded the mission to include ground ops. That's where the very high positional accuracy is needed, not in flight.
Bob, do you have a feed back link to FAA?

Just seems if ground clearance requirement could be amended to exempt light aircraft, problem would be over and small companies like Naxworx could get on with providing a reasonably priced system to meet the requirement.

I have a link to FAA regarding the rebate program, I was able to easily cancel reservation but not otherwise. I suppose the way to go would be to submit a comment regarding the proposed AD.
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  #37  
Old 10-23-2016, 03:00 PM
David-aviator David-aviator is offline
 
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With regard to above, I just filed a comment with FAA and proposed AD.

It was easy, just go to first message this thread and do it after hitting AD link.
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  #38  
Old 10-24-2016, 08:09 AM
kevin O kevin O is offline
 
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Default AD

The comments in the AD make some very interesting reading. If all 800 owners responded to the AD perhaps it would make a difference. Particularly on the financial impact. The $85 stated in the AD is ridiculous. The current AD will require us to replace the Navworx. Would be nice to hear from Navworx. Anybody been able to contact Navworx that has some proposed solutions?
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  #39  
Old 10-24-2016, 10:50 AM
Abbygirl1 Abbygirl1 is offline
 
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Default No answer

No answer from email, phone goes straight to voicemail........doesn't look good.
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  #40  
Old 10-24-2016, 02:51 PM
330drvr 330drvr is offline
 
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I wouldn't worry too much about that. Bill is probably pretty busy right now. I have had the 600B for years and love it. I always thought that eventually I would pay for a certified GPS to go in the box. Getting the software that did it without changing the GPS was great but it doesn't seem insurmountable to remove and replace with a certified unit.

Options seem as follows (for my case):

1. Bill Moffett and FAA reach some sort of agreement and the proposed AD is withdrawn.

2. Box goes back to TX and certified GPS installed for a reasonable amount of cash. Bill cannot be expected to do this for nothing.

3. I use the serial port from the GNS480 with the Garmin ADSB+ output to input the certified position to the 600B. I can't use the ARINC 429 outputs because I am using both already to the GRT EFIS. I know this (or similar) option for the EXP is not feasible.

I think a solution will work itself out.
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