Author Topic: Testing ADSB using the pilotaware  (Read 4782 times)

Huntwing

Testing ADSB using the pilotaware
« on: April 13, 2018, 08:52:46 am »
I have been asked to test and sign off a number of ADSB installations over the last 18 months and was able to use my pilotaware to do this quite easily. However over the last 6 months I have struggled to see ADSB on a number of aircraft, both with Trig and Funkwerke installations, despite knowing that they are working (the devices are displaying location and are showing up on Flightradar).

In all cases they are also running Pilotaware and the P3l output displays within the traffic screen but not the ADSB (---P- instead of CSAP-) similarly ADSB status does not appear.
However if its left on long enough in most cases it does appear for a brief period, which then populates the ADSB status fields and these seem to stay there after it has returned to ---P-. Its as if the P3l is overriding the ADSB.

As the majority of these aircraft are taking their GPS feed from the spare port on the Pilotaware we have not been able to turn off the pilotaware and I ac concerned to remove the P3i antenna for fear of damaging the output stage of the Pilotaware board.

Any solutions would be appreciated.

Kind regards


john

PaulSS

Re: Testing ADSB using the pilotaware
« Reply #1 on: April 13, 2018, 09:28:25 am »
Quote
As the majority of these aircraft are taking their GPS feed from the spare port on the Pilotaware

Hi John,

As an interested bystander, did you get the same result if the GPS feed was from a different source e.g. EFIS?

AlanB

Re: Testing ADSB using the pilotaware
« Reply #2 on: April 13, 2018, 09:53:57 am »

As the majority of these aircraft are taking their GPS feed from the spare port on the Pilotaware we have not been able to turn off the pilotaware and I ac concerned to remove the P3i antenna for fear of damaging the output stage of the Pilotaware board.

Any solutions would be appreciated.

Kind regards


john

Would temperarily changing the A/C id in the pilot aware for the aircraft under test solve the problem. That way the PAW would see two separate targets, ADS-B and PAW responses, at the same location but list them as independent targets.
Europa XS Mode-S ADS-B out enabled.

Ian Melville

Re: Testing ADSB using the pilotaware
« Reply #3 on: April 13, 2018, 11:03:46 am »
I think they would show as two targets.
My first thought was that you should at least see mode C/S. IIRC some one else had this issue?
I would also check that the transponders are getting the GPS fix.

Trying to check on phone is a PITA, will check later if no one else chips in.

Huntwing

Re: Testing ADSB using the pilotaware
« Reply #4 on: April 13, 2018, 12:25:31 pm »
They are definately getting the correct feed, as I said they appear on Skyradar and the trig tells you when it isnt getting a feed as well as displaying the coordinates when you press the function button twice. The Funke is also showing the coordinates when you go into the show setup mode.

My own system (using a sperate GPS feed) and running over a year and clearly working on Flightradar does not show up either on as ADSB on my friends Pilotaware but I haven't tried switching off my pilotaware which will be the next test.

John

Admin

Re: Testing ADSB using the pilotaware
« Reply #5 on: April 13, 2018, 12:53:51 pm »
Hi John

I recall there was another thread here on the forum that discussed some bugs in the firmware for ADS-B transponders - I cannot recall which, and I think they fell into 2 categories

1. ADS-B transmit was only working when interrogated from a ground RADAR
So in this case, whilst on the ground, in a hangar etc, the ADS-B was not sending DF17 unless it was being interrogated on 1030Mhz. This is in fact wrong because ADS-B should be sent unconditionally

2. ADS-B transmit only when not stationary
Another case we heard about was whereby the ADS-B transmit function is suppressed if the groundspeed is below a certain threshold.

Could either of these be possible ?

Thx
Lee

Admin

Re: Testing ADSB using the pilotaware
« Reply #6 on: April 13, 2018, 12:57:39 pm »
...
My own system (using a sperate GPS feed) and running over a year and clearly working on Flightradar does not show up either on as ADSB on my friends Pilotaware but I haven't tried switching off my pilotaware which will be the next test.

Hi John,
is this in the air or on the ground ?
And just to confirm the FlightRadar apture is ADS-B and not MLAT ?
Thx
Lee

Huntwing

Re: Testing ADSB using the pilotaware
« Reply #7 on: April 14, 2018, 06:10:33 pm »
This is on the ground, however not in hanger and they show signs they are being interrogated, although this shouldn’t matter for ADSB. This used to work fine it’s only over the last 6 months or so I have struggled.

John

Huntwing

Re: Testing ADSB using the pilotaware
« Reply #8 on: April 14, 2018, 11:03:16 pm »
Almost certainly not MLAT. Only shows on flight radar when ADSB is activated.
John

PaulSS

Re: Testing ADSB using the pilotaware
« Reply #9 on: April 20, 2018, 05:24:09 am »
Quote
This is on the ground

I know that a squat switch can be fitted to the transponders and I also know that different EFISISIS (EFII) can be configured to trigger an 'in flight' signal to the transponder. Obviously the transponder will push out different wigglies depending on if it's on the ground or in the air. On the ground it may well not be pushing out ADSB because it's not meant to but if there's an interrogator nearby then the aircraft may show on some of the 3rd party receivers because of MLAT. I think it might be worth looking at the avionics setup in those aircraft and if any of them have an EFIS, set it up so that is is always in flight and that might get the ADSB doing its thing. If they don't have an EFIS, do they have a squat switch? If so then it's pretty obvious what to do and if none of the above, maybe have a squint at the installation manual to see what the default mode is of the transponder. Perhaps it might trigger its own flight mode if it detects a reduction in static pressure over a short period......that's just a pure guess and based on no evidence whatsoever.

Sorry but I've just realised I might have re-suggested what Lee was referring to above  :-[
« Last Edit: April 20, 2018, 05:27:16 am by PaulSS »

Huntwing

Re: Testing ADSB using the pilotaware
« Reply #10 on: April 23, 2018, 11:21:18 am »
As stated previously this used to work OK on the ground and I tested it on numerous occasions for both Funke and Trig installations.

It appears to only work now when flying, despite the fact that you can see interrogations of the Transponder on the ground and the fact that ADSB is broadcast not reliant on interrogation.

I tested my own setup yesterday whilst flying but briefly connecting to a second pilotaware which was factory set and it worked perfectly. All of my flights, and the others I have tested sho up on Planefinder as soon as we switch on the GOS source so we know they are working.

So still confused as to why I can only get the full CSAP showing when in flight but will have to get people to fly around now to capture screen shot.

John

Admin

Re: Testing ADSB using the pilotaware
« Reply #11 on: April 23, 2018, 01:23:46 pm »
Hi John

I went back through your earlier comments, and I think this may be important here
Quote
However if its left on long enough in most cases it does appear for a brief period, which then populates the ADSB status fields and these seem to stay there after it has returned to ---P-. Its as if the P3l is overriding the ADSB.

There is actually a minor display bug here, you are correct that when a P3I transmission is received it deletes the flag saying ADS-B was received, BUT this is only a display issue and the important fields for ADS-B should remain

vers nacp sda nica sil sils

Is this the case, that these fields are still set ?

This display issue is fixed internally, and will be in the next release.

So can I confirm, the only issue you were reporting is that you were seeing
---P-, and not the expected CSAP-

If you wish I could give early access to the version that corrects this ?

thx
Lee