ADSB for VFR

[jetjr]

VFR ADS-B Discussion Paper under Preparation - Australian Flying

 

Anyone else guess where this is going?

 

 

[kaz3g]

Enigma released details of their "low cost" ADSB 12 months ago but I don't know if it has ever been approved for VFR use.

 

I can't afford $3.5k+ to replace my perfectly good Microair and I don't know what the story is with an encoder which could be an additional expense.

 

When all this was originally being floated, there was much talk of ASA subsidising cost because of the massive savings it brings them by reducing upkeep on old infrastructure. Pigs might fly but a couple of g's to defray the cost would help a lot.

 

Kaz

 

 

[jetjr]

Yes

 

Their idea of affordable is different to mine

 

 

[graham brown]

Where this goes will depend on the cost and the benefits. VFR ADSB will take away the need for Airservices to keep secondary radar going saving them $ in the future. However I don't think any subsidy will happen. C mode transponders will work until the secondary radars are shut down and this should be a way off. However they are shutting down ndb and vor now. The ASTRA proposal is for a low powered, low cost, non mandatory standard. Low cost being the same cost as a vhf radio but that will be set by the market. C199 the standard for the units allows commercial gps units which will keep the costs down. The benefits will be everyone can see you and if you fit adsb in you can see them. I have flarm in my glider however the range is short and only flarm can see it. Mobile phone network based solutions such as oz runways etc are restricted too. All IFR aircraft are adsb equiped now and Airservices have installed an adsb ground receiving network so it's the way we are going in this GPS improved world.

 

 

[jetjr]

Lots of debate points here but as with IFR adsb, not many who paid for the gear are seeing benefits. Significant numbers of IFR aircraft simply are now VFR

 

I also thought ADSB coverage was limited under certain height and what about thousands of non radio or Transponder equipped aircraft

 

We arent just talking aircraft that enter CTA anymore.

 

 

[kaz3g]

I emailed Enigma and their response was that they have been ignored by CASA for years and are still,awaiting approval for their product which they hope to sell at an installed price of less than $3k.

 

It will go off shore like so many technological developments and Governments should be ashamed of their lack of support.

 

Kaz

 

 

[graham brown]

VFR adsb will be non mandatory so it won't be needed in class g airspace. However the value I see in class g airspace is air to air visibility like flarm but you also alert the regional airlines, air ambulances and the other fast guys. Enigma's devices are good and will probably compete when the standard is put out by casa. They will be competing with the other manufacturers so the price may have to come down. They are well before the times and I hope they make it. Government has not supported any technology in 20 years and this is why we dig up coal, iron ore and export gas at ever diminishing prices. Very discouraging!

 

 

[jetjr]

VFR adsb will be non mandatory so it won't be needed in class g airspace.

I find it tough to believe ASA and CASA would let this happen

 

A nice benefit for them is ability to track and charge for services and maybe even airspace.

 

 

[Mike Borgelt]

A mode C transponder allows TCAS equipped aircraft to see you even outside radar coverage.

 

It would have been nice for ADSB not to be a complete stuff up. Using the 1090Mhz transponder reply frequency is about the worst possible decision ever made. There were 3 other frequencies/systems under consideration originally. 1090 won because you could connect a suitable GPS to a suitable Mode S transponder which a lot of airliners already had.

 

It should have been possible to reserve a couple of frequencies in the VHF comms band for data and use those without even interfering with the radio for VHF voice. Then the installation is already done and the frequency suffers less from airframe shielding.

 

FLARM as currently implemented is pretty dodgy as it uses 921MHz and very low power. It was designed as the gliding equivalent of CWIS (Close in Weapons System) on navy ships for last ditch defence against cruise missiles. You don't want to have to use it as you hope the launch vehicle for the missile got sunk/shot down before launch.

 

In the European Alps on a nice day, thousands of gliders fly in lift in close proximity to mountainsides on converging courses at closing speeds of up to 200 knots or so. There were sometimes over a dozen mid airs a year there. FLARM was invented to try to prevent that but modern gliders have carbon fuselages and airframe shielding is a serious problem requiring very careful antenna placement and installation.

 

Now whatever system is used I have to ask - if you can seen by everyone else beyond visual range and you can see them why would anyone want air traffic control? I'd support ADSB for VFR if we could get rid of much of the controlled and restricted airspace as a result. Our scale model armed forces seem to have inordinate quantities of restricted airspace.

 

 

[graham brown]

I agree it's about airspace. Restricted airspace, lowering class e airspace, regional airlines saying its unsafe to fly in class g with pesky other vfr traffic. A low cost vfr adsb will go someway to protect our access to airspace and also provide assistance to see and avoid. ATC are not needed. Non mandatory is key as most class g airspace has no one in it. If you fly in a busy area it might be a good idea to fit one for your own safety. Authorities mandating it usually costs us a fortune and the safety benefits are not there.

 

 

[jetjr]

Only adsb OUT is mandatory, to get reliable IN costs extra and its all only as good as the GPS signal

 

Pretty sure it fell over a few months ago and does give rough results often

 

 

[derekliston]

My Trig transponder that came with the Skyview package has ADSB out.

 

 

[Mike Borgelt]

Only officially if the GPS is properly TSO'd, Derek. In the US the GPS is allowed to be one which meets the TSO requirements but has not been formally approved to do so, in EXPERIMENTAL homebuilts and LSA at least for VFR. Not sure for IFR in homebuilts. Not so here, yet.

 

Both ADSB IN and OUT depend on the GPS working. Nowadays GNSS would be better as multiconstellation chips/antennas are cheap. Currently there is GPS, Glonass, Beidou, Galileo, QZSS and IRNSS. Search for a little app for Android and iDevices called GNSS View. Also at GNSS View

 

 

[derekliston]

Only officially if the GPS is properly TSO'd, Derek. In the US the GPS is allowed to be one which meets the TSO requirements but has not been formally approved to do so, in EXPERIMENTAL homebuilts and LSA at least for VFR. Not sure for IFR in homebuilts. Not so here, yet.Both ADSB IN and OUT depend on the GPS working. Nowadays GNSS would be better as multiconstellation chips/antennas are cheap. Currently there is GPS, Glonass, Beidou, Galileo, QZSS and IRNSS. Search for a little app for Android and iDevices called GNSS View. Also at GNSS View

Registered with Airservices who told me all good but can't be used for separation purposes, so probably not a lot more use than just transponder except I suppose they know who I am?

 

 

[Mike Borgelt]

Mode S tells them who you are and that combined with SSR should be able to be used for separation. I guess they just ignore your ADSB GPS derived position. Betcha that GPS position is better than they can get from the radar.

 

 

[graham brown]

Indeed it will be. In fact Airservices check their radars with adsb now. It is proposed that vfr adsb can use commercial gps/gnss and the surveillance integrity level can be set at 1 which means TCAS can use it.

 

 

[Bruce Tuncks]

These devices could in theory be used to open up more airspace for vfr and raaus use. Alas they could also be used to enforce restrictions even if the restrictions were useless.

 

For example, a guy who was flying near Burra in South Australia with his stupid transponder turned on got into trouble for " violating airspace". The said airspace had not been used for 50 years and on the day in question ( 10,000 ft thermals) there would have been thousands of soaring birds in that same airspace.

 

I wonder which way the outcome will go? more freedom or more policing?

 

 

[graham brown]

Hopefully more freedom. I think the controllers like the rest of us are getting more work load not less so hopefully leave us alone. With adsb it has the integrity levels Nic,nac,sil etc and accordingly atc can ignore various levels. The proposed vfr adsb will be designed to TSO c199 but not certified so this should mean they are cheaper. Also the integrity levels will be set low but not zero so they can be filtered out by atc but not tcas and adsb in. Some of the manufactures have units all in a box with adsb in that Bluetooth to your phone or efis. Air to air is the benefit for us like flarm. We wait for the price!

 

 

[jetboy]

It would have been nice for ADSB not to be a complete stuff up. Using the 1090Mhz transponder reply frequency is about the worst possible decision ever made. There were 3 other frequencies/systems under consideration originally. 1090 won because you could connect a suitable GPS to a suitable Mode S transponder which a lot of airliners already had.It should have been possible to reserve a couple of frequencies in the VHF comms band for data and use those without even interfering with the radio for VHF voice. Then the installation is already done and the frequency suffers less from airframe shielding.

Mike, this would have been ideal for OZ and NZ.

 

With the proliferation of new design radios for the experimental / microlight / LSA aircraft - like the Microair and Xcom, there is opportunity to incorporate VDL (VHF data link) ADSB functionality into them at very low cost. All thats needed is an auxillary data input to the rear connector and a software revision to store that data and transmit the burst at a time the radio is idle. The interruption would be no greater than that of the alternate frequency watch scan these radios have. The box needed to produce the data could be a $20 GPS chip and $5 PiZero.

 

I was promoting this for the purpose of meeting the NZ proposed requirement for aircraft location devices to replace 121.5 ELTs, but the discussion papers specifically prohibited this type of system, similarly the experts have adopted 1090 rather than the American 900MHz or European used VHF frequencies for ADSB.

 

So we all have to perpetuate installing new 250 Watt mode S ES transponders in aircraft that wont get used for that role once the radars are shut down.

 

On the matter of subsidy, I recall the FAA promised to pay for all the GA installations because it was easily met in their budget by the savings in shutting down their radars. the reality was quite different.

 

In NZ transponders were introduced to GA by offer of "subsidy" loans - the terms were something like a 10 year interest free loan paid at $300 / year on a transponder installation if that installation was ordered in a bulk scheme and installed by the bulk scheme supplier. I think the transponder cost about $3000 at the time (circa 1977) so when you work the numbers for a bulk discount it didnt really cost the DCA anything other than borrowing some other taxpayers money for a while. It still cost each and every GA operator the full cost of putting zero benefit gear in their planes and paying the cost of checking them. If you came in after the promotional scheme there was no "subsidy"

 

 

[Mike Borgelt]

I know the original MicroAir designer demonstrated such a system to CASA in Canberra 20 years ago. They thought it was wonderful until they realised it wasn't an international standard and promptly lost interest. It really would have been the best and by far the cheapest. Flarm would never have got off the ground.

 

 

[apm]

Discussion paper is out, wonder if Microair could resubmit now, possible that CASA has realized VFR is not going to be easy to equip with current ADSB so need to look at cheaper options for us.

 

Ozrunways & Avplan could hook into Airservices to send device location & receive ADSB info to redistribute to devices. would probably not be considered accurate but would be cheap.

 

 

[Yenn]

The problem with ADSB as I see it is that the manufacturer has to get the equipment certified. That increases the price greatly. If CASA are happy to let cheaper, uncertified equipment be used, then it may be possible for a lot more aircraft to be fitted with ADSB out. I would welcome it, because of the greater safety, but having very good visibility in my planes I am not going to spend thousands for slightly better safety outcomes.

 

The system used by Avplan and Ausrunways works well. Pity one cannot see the other.

 

I listened in to a commercial pilot talking to area the other day. He asked if they knew of another aircraft close to him as he could see it on his tablet. Area didn't know what he was talking about, so he had to explain to them. My guess is that someone in his plane was using Avplan or Ausrunways.

 

I filled in the questionaire and said just about what I say here. Several of the questions were beyond my level of expertise, so don't know was used.

 

 

[derekliston]

The problem with ADSB as I see it is that the manufacturer has to get the equipment certified. That increases the price greatly. If CASA are happy to let cheaper, uncertified equipment be used, then it may be possible for a lot more aircraft to be fitted with ADSB out. I would welcome it, because of the greater safety, but having very good visibility in my planes I am not going to spend thousands for slightly better safety outcomes.The system used by Avplan and Ausrunways works well. Pity one cannot see the other.

I listened in to a commercial pilot talking to area the other day. He asked if they knew of another aircraft close to him as he could see it on his tablet. Area didn't know what he was talking about, so he had to explain to them. My guess is that someone in his plane was using Avplan or Ausrunways.

 

I filled in the questionaire and said just about what I say here. Several of the questions were beyond my level of expertise, so don't know was used.

I have ADSB out in my CH701 as part of my Skyview system. Airservices tell me it cannot be used for navigational clearance purposes so really, is it any more use than a normal transponder?

 

 

[Kyle Communications]

My talk with a CASA guy was he told me its not CASA who is the stumbling block with "certified" ADSB it is Air Services letting non certified onto their system. Infact CASA was the one who initiated the discussion with air services about it

 

 

[Kyle Communications]

Ruff All I can tell you I was having a conversation with a person in CASA who is in our section of management who I know quite well and I was talking about transponders and that I think everyone should have them but the issue is the cost. The certified units are just way over priced for what they are and the certified GPS as well but if everyone had them then at least there would be another set of eyes on everyone and I think would improve safety when going cross country or at least out of the circuit areas. Its very hard in the circuit as there are a lot who just dont look at where they are flying or who and what is in the circuit. That I believe is the most dangerous time. But if we had a transponder when the ATC calls on the area freq at least your not guessing who they are talking about as I have experienced a few times.

 

The electronics in them really is nothing special at all and should be no more expensive than a normal radio. After all its just another radio that transmits a data signal not a voice signal but on a lot higher band. The GPS input side also a crock. 99% of any std GPS is well good enough to give your position and height encoders are NOT expensive anymore.

 

So the conversation was he told me that CASA had broached the subject with Air Services as they are the ones who allow and manage it and were having a talk about it all. How long this takes is anyones guess and it may not even get off the ground at all but at least the idea is out there. Some will whinge about extra money etc blah blah I mean some even refuse to pay for a radio for gods sake

 

Mark