VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

  #81  
Old 10-31-2016, 01:20 PM
aerovin aerovin is offline
 
Join Date: Nov 2007
Location: Lincoln, CA
Posts: 138
Default

So, looking at TSO C154c and AC 20-165, the difference between SIL 3 and SIL 0 precision is as outlined in the table from the AC:

AC 20-165

Figure 7. Probability of Exceeding the NIC Containment Radius.

SIL Value
Probability of exceeding the NIC containment radius
3 ≤ 1x10-7 Per Hour or Sample
2 ≤ 1x10-5 Per Hour or Sample
1 ≤ 1x10-3 Per Hour or Sample
0 > 1x10-3 Per Hour or Sample or Unknown


And, it would appear that the manufacturer, by changing the transmitted SIL value from "0" to "3" in the software change, is implying that its non-approved GPS position source has demonstrated that level of precision.

So it would seem that the basic question is whether or not the position source actually has demonstrated that performance requirement as required by the TSO.
__________________
Scott Thompson
RV-8 N9324Z (flying as of 8/30/15)
http://www.aerovintage.com/rv8/rv8-index.htm
Reply With Quote
  #82  
Old 11-09-2016, 07:09 PM
DennisRhodes DennisRhodes is offline
 
Join Date: Jul 2007
Location: Taylorsville, Ga
Posts: 849
Default

Has anyone heard anything out of Navworx or FAA lately on status of AD? Any sign of possible resolution or compromise for the 600 EXP units?
__________________
DRRhodes
2020 VAF Supporter
RV9 N908DR
Reply With Quote
  #83  
Old 11-10-2016, 06:49 AM
rleffler's Avatar
rleffler rleffler is offline
 
Join Date: Jun 2006
Location: Delaware, OH (KDLZ)
Posts: 4,225
Default

Quote:
Originally Posted by DennisRhodes View Post
Has anyone heard anything out of Navworx or FAA lately on status of AD? Any sign of possible resolution or compromise for the 600 EXP units?
Per the Navworx web site:

Currently we are waiting on the resolution of the AD on or about December 20th. Based on the final AD, the AD may be rescinded, or the AD may be modified to allow for just previously approved GPS sources.


I wouldn't expect to hear any updates from Bill until the first of the year.
__________________
Bob Leffler
N410BL - RV10 Flying
http://mykitlog.com/rleffler
Reply With Quote
  #84  
Old 11-10-2016, 03:49 PM
Paul 5r4 Paul 5r4 is offline
 
Join Date: Oct 2006
Location: Foley, Al
Posts: 604
Default 600 EXP units

I too have the exp model. I sent Bill a message on Nov 2nd asking about the exp model since it wasn't mentioned in their letter on their website and received this reply:

"We're working that now in case the EXP stays on the AD , but it shouldn't as it meets the FAA policy and performance requirements for experimental aircraft." Bill Moffitt

I didn't really understand the response because the exp met the performance requirements when it was first placed on the AD list by the FAA!
__________________
Paul Gray
Foley, Alabama
N729PG..... 450+ hrs
RV 7A, Lycoming 0 320 D1A, Sensenich FP propeller
pilotforfun2001@yahoo.com
VAF supporter $$$
Reply With Quote
  #85  
Old 11-10-2016, 05:41 PM
MartySantic's Avatar
MartySantic MartySantic is offline
 
Join Date: Apr 2008
Location: Davenport, IA
Posts: 1,390
Default

Quote:
Originally Posted by Paul 5r4 View Post
"We're working that now in case the EXP stays on the AD , but it shouldn't as it meets the FAA policy and performance requirements for experimental aircraft." Bill Moffitt
I too do not understand the response. Are the policies and performance requirements different for experimental aircraft vs. certified?

Would sure like to see someone state the facts so I can formulate a response to the AD that is based on fact and not hearsay & guesses. Does Navworx have the supporting information that indicates the TSO requirements have been met? Or the the FAA concluding it does not because a specific GPS chipset was not used.

The recent midair collisions that have made news in recent weeks could have been avoided with a GPS accurate to hundreds of feet. An accuracy of a few feet would not have provided any more useful information to those that perished.
__________________
Marty Santic ----- W9EAA
RV-12 N128MS ----- Now Flying
My RV-12 Build Log - http://www.martysrv12.blogspot.com/
Davenport, IA

Last edited by MartySantic : 11-10-2016 at 06:16 PM.
Reply With Quote
  #86  
Old 11-10-2016, 06:52 PM
DennisRhodes DennisRhodes is offline
 
Join Date: Jul 2007
Location: Taylorsville, Ga
Posts: 849
Default

Agree that the information is limited at best to be able to respond to the AD. I would like to respond that the ADS 600 Exp unit should be dropped from the AD due to the fact that the FAA accepted the performance of that unit some time ago as per Navworx,and can be installed on an experimental ,But haven't done that yet due to lack of info.
__________________
DRRhodes
2020 VAF Supporter
RV9 N908DR
Reply With Quote
  #87  
Old 11-18-2016, 09:17 AM
MartySantic's Avatar
MartySantic MartySantic is offline
 
Join Date: Apr 2008
Location: Davenport, IA
Posts: 1,390
Default My Navworx AD Response

I am listing my response here and soliciting ALL to submit a comment on the FAA website.

https://www.regulations.gov/docketBr...=FAA-2016-9226

The National Transportation Safety Board issued a Safety Alert Nov. 15, 2016, to pilots with suggestions on what they can do to reduce their chances of being involved in a midair collision.

SEE and AVOID ONLY GOES SO FAR.

Two recent mid-air collisions exemplify this point. On July 7, 2015, a Cessna 150 and an F-16 Air Force fighter jet on a training mission collided. An air traffic controller advised the F-16 pilot that the Cessna was a potential traffic conflict. The F-16 pilot was not able to visually acquire the Cessna until it was too late to avoid the collision. The two occupants of the Cessna were KILLED; the F-16 pilot ejected and survived. On Aug. 16, 2015, a North American Rockwell Sabreliner inbound for landing a Cessna 172 that was practicing landings at the same airport collided. The four occupants of the Sabreliner and the sole occupant of the Cessna were KILLED.

The Safety Alert highlights the value of traffic avoidance technologies to pilots as an aid to detecting and avoiding other airplanes in flight.

The proposed AD is clearly CONTRARY to this NTSB recommendation. AND is contrary to the desires of the FAA to equip most if not all with ADS-B out. AND is contrary to the NSTB 2017-2018 MOST WANTED LIST. The first listed HERE is to INCREASE IMPLEMENTATION OF COLLISION AVIODANCE TECHNOOGY.

Many have purchased the Navworx ADS-B transceiver because it was listed by the FAA as a unit approved and eligible for the rebate. The proposed AD mandating removal, months after, makes many VERY unhappy. In addition, the cost to the Navworx owner as listed in the proposed AD is in error. The cost to the owner should not only include a reasonable estimate of the A&P removal cost (4 hours at $80/hour) but should also include the cost of a new ADS-B transceiver and its installation costs.

I fly with the Navworx ADS-B transceiver installed. After flying with this equipment for 9 months, it clearly provides me with a very much desired safety margin. I fly in VFR conditions and my experimental aircraft is NOT IFR equipped. FAA?s concern appears to be with the accuracy of the Navworx reported GPS position. I DO NOT, nor do I believe many others need an accuracy of inches or a foot. This is clearly a case where engineers developed a set of specifications and did not use any engineering judgement whatsoever, nor did they consider the multitude variations where the ADS-B out units could be installed. (Certified vs. Experimental, VFR vs. IFR, etc., Light planes vs. those that utilize Class A airspace.)

The FAA must reconsider the ramifications of the proposed AD and either cancel it or revise it. If I am forced to disable and remove the Navworx equipment, the probability of me being involved in a mid-air collision has increased many-fold.
__________________
Marty Santic ----- W9EAA
RV-12 N128MS ----- Now Flying
My RV-12 Build Log - http://www.martysrv12.blogspot.com/
Davenport, IA
Reply With Quote
  #88  
Old 11-18-2016, 03:10 PM
N743RV N743RV is offline
 
Join Date: May 2009
Location: Livermore, CA
Posts: 57
Default Navworx ADSB...comments to FAA

Here are the comments I posted on the FAA site:

"
1. This Proposed rule will decrease MY Safety!! Without the Navworx ADS600 I will be unable to see other traffic.

2. I rely on my unit to spot VFR traffic and it has already avoided several significant traffic conflicts. Without ADS-B readout in the busy airspace I fly (San Francisco Bay Area) my safety and the safety of my passengers is significantly degraded!!!

3. The estimate of this AD costing only $85 is not based in reality. I have over $8000 of parts and labor invested in my adopting the required ADS-B out requirement and it will cost at least $500 to remove the unit and another $500 to reinstall the Navworx assuming they modify it for free. If I have to buy a new unit that's at least $2500 more. So at a minimum, this Proposed rule will cost me $$1,000 hours and at most $11,500.

4. The proposed rule does not quantify the safety risk of continued operation with the subject hardware. I believe it must be very small, so if the proposed rule must move forward, I would suggest a reasonable period of time to comply with the rule...not "remove the hardware immediately". I would suggest 1 year from AD issue?

5. I suggest that the proposed rule address VFR and IFR use separately. I believe the time to reach compliance for "use only in VFR conditions" should be one year as a minimum and maybe should not even apply to VFR only use!"

Bob Cowan
RV-7a, 400 +hrs
Reply With Quote
  #89  
Old 11-18-2016, 03:20 PM
Paul 5r4 Paul 5r4 is offline
 
Join Date: Oct 2006
Location: Foley, Al
Posts: 604
Default 800 units effected?????

This AD is supposed to affect only 800 aircraft!!! That's a lot of airplanes! One additional thought to consider is this.... That's 800 units alone... there are untold folks flying with the benefit of just the ADSB IN. So, if each of the 800 affected aircraft is always sending a signal to another 3-5 airplanes in their umbrella of coverage then the much truer number is something like an ADDITIONAL 2400 to 4000 aircraft on top of the 800! I understanding this is speculation. I thought of this after a chat with my hanger neighbor who has just ADSB in. Sometimes he's piggybacked on me so if I'm not ADSB out equipped that's me and another plus an unknown amount more affected. Food for thought.
__________________
Paul Gray
Foley, Alabama
N729PG..... 450+ hrs
RV 7A, Lycoming 0 320 D1A, Sensenich FP propeller
pilotforfun2001@yahoo.com
VAF supporter $$$
Reply With Quote
  #90  
Old 11-18-2016, 03:51 PM
MartySantic's Avatar
MartySantic MartySantic is offline
 
Join Date: Apr 2008
Location: Davenport, IA
Posts: 1,390
Default

Quote:
Originally Posted by Paul 5r4 View Post
This AD is supposed to affect only 800 aircraft!!! That's a lot of airplanes! One additional thought to consider is this.... That's 800 units alone... there are untold folks flying with the benefit of just the ADSB IN. So, if each of the 800 affected aircraft is always sending a signal to another 3-5 airplanes in their umbrella of coverage then the much truer number is something like an ADDITIONAL 2400 to 4000 aircraft on top of the 800! I understanding this is speculation. I thought of this after a chat with my hanger neighbor who has just ADSB in. Sometimes he's piggybacked on me so if I'm not ADSB out equipped that's me and another plus an unknown amount more affected. Food for thought.
Your point is well founded. PLEASE post as an AD comment on the FAA website!
__________________
Marty Santic ----- W9EAA
RV-12 N128MS ----- Now Flying
My RV-12 Build Log - http://www.martysrv12.blogspot.com/
Davenport, IA
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 11:04 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.