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Avidyne R9 (non GNS GPS) stops working with too many satellites?

Stephen describes this here

Are any other products affected by this e.g. the IFD540?

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

This is a pretty nice example how the certification process creates the problems it was created to solve. In this case a safety problem.

I see what he means, but I think he is taking it a bit too far. It can’t possibly take a year to certify what is more or less an emergency fix and which is probably trivial. Considering Avidyne’s track record with the IFD540, I wonder how hard they have really been pushing the certification of the fix.

ESKC (Uppsala/Sundbro), Sweden

My guess is that this is somehow EGNOS related.

There is “zero” EGNOS coverage in the USA.

It cannot be just Galileo + Glonass because AFAIK there is no way to arrange the orbital mechanics so that the satellites avoid the USA And a huge stink would have been made in the USA… both in the R9 user community over there which is far bigger than in Europe, and in the (hypothetical) EU decision to launch a load of navigation satellites which switch off their transmitters, or reduce the power output, while over the USA. GPS is not like the spot beam based geostationary systems e.g. Thuraya or Immarsat which can turn off some of their spot beams to deny coverage to certain regions, and which in any case – certainly for phone+data applications – can deny service to anybody not returning the desired GPS coordinates.

When the IFD540 came out, it didn’t work with EGNOS either (Avidyne seemingly never tested it in Europe) but it didn’t crash; it just didn’t work for LPV.

Administrator
Shoreham EGKA, United Kingdom

Unfortunately I am as blind as probably anyone else. I can only talk about what I observed on two different R9 aircraft between April 2014 and now.

My sources are the COPA forum and the Avidyne Online Community at http://forums.avidyne.com/default.asp Avidyne customer support is responsive and trying to help but obviously they can only help with what is available to them.

As much as everyone else I would also like to understand what is causing the issue in the first place. But I guess that’s probably something we will never learn.

Wouldn’t it be great for some basic parts of avionics software become open source

Frequent travels around Europe

Peter wrote:

GPS is not like the spot beam based geostationary systems

No but they aren’t geostationary either. GPS satellites can turn off their output in certain geographical areas. I experienced this when flying to Croatia when the Bosnian no-fly zone was active – when getting too close to it, GPS signals quite suddenly stopped…

LSZK, Switzerland

Sure it wasn’t jamming? I got all three GPSs go wild in 2004 while flying past Croatia, down the middle of the Adriatic (the Italians told me to keep away from their airport zones ). But no loss of signal. Obviously it was jamming.

The antenna radiation cone is pretty wide.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

Sure it wasn’t jamming?

I didn’t hook up a spectrum analyzer or anything to the antenna, but otherwise, yes, I’m pretty sure. Signal levels actually gradually dropped.

Peter wrote:

The antenna radiation cone is pretty wide.

Yes, that’s why they had to shut down half of Croatia in order to reliably have no signal in the no-fly zone

LSZK, Switzerland

Some good news from Avidyne: Avidyne Forum

Software Release 9.3.3 has been approved by the FAA. A service bulletin has been issued and is available for Avidyne dealers. Please contact your local Avidyne approved dealer to have the update completed.

This software corrects:
- Dual GPS dropouts for customers operating in EGNOS coverage areas
- 8.33kHz radio fix
- Issues affecting CDI indications on GPS approaches that caused the AD issued in May 2015

LSGL

Good, that they finally fixed that, Stephan will be pleased :-)

This software corrects:
- Dual GPS dropouts for customers operating in EGNOS coverage areas
- 8.33kHz radio fix
- Issues affecting CDI indications on GPS approaches that caused the AD issued in May 2015

and it is now December 2015. What have IFD540 users in Europe been doing since the IFD540 started shipping? Navigating with an Ipad?

The 8.33 issue is of a similar age. An 8.33 handheld radio? One actually cannot fly IFR now without 8.33 because while not many stations use it, you need only the one… and with Dutch Military being 8.33 for some months now, VFR is questionable also unless one dives down to a low level and stays totally OCAS.

My long term plan is to install 2 × IFD540 but it doesn’t look good…

Administrator
Shoreham EGKA, United Kingdom
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