Airservices GBAS announcement – a disaster for GA

[Quokka]

Thanks for the clarification onthedials.

That was the best-written technical post on the subject in this thread that I've read so far. I was hoping to differentiate the RADAR vs. ADS-B debate from the GBAS vs GRAS vs WAAS vs everything-else-that-was-being-thrown-into-the-thread debate.

I oversimplified the GPS/Transponder aspect of it and I apologize for doing so.

[LeadSled]

Onthedials,
You'r getting close, but some caution.
The AC lists a number of "big end of town" items that are all only C129A GPS, not just the King. The fine print says they have to be phased out too soon to amortise, unless the GPS is just a feed to an IRS/FMCS typical setup.
Very few existing GPS boxes can be upgraded from C129A to C145/146, the internal workings are quite different. Despite all the smoke and mirrors, the only GA C146 Garmin is the 480, inherited from the takeover of UPS technologies. As far as I can see from the Garmin website, while future model 430/530 may have C145/146, I don't see any blurb about retrofitting existing boxes.
Likewise, very few Mode S transponders can be upgraded to 1090ES, probably because the manufacturers want to sell you a new transponder. My Collins TDR 94 transponders can't be upgraded, current production but "wrong" serial number, just like most of the Qf -8s, and a whole bunch of other Regional aircraft. A pair of TDR94D ain't cheap.
Microair is soldiering valiantly on, but the whole project depends on a C146 GPS chip at an affordable price. Will that happen ?, with only one source of supply, who knows, I hope so, but don't hold your breath.
Gaunty, GBAS and GRAS are not the same, Airservices is playing footsies with Honeywell over GRAS, not Honeywell GBAS products.
Tootle pip!!

[SCE to Aux]

The Garmin 480 now has some company in the TSO C145/146 arena.

Current Garmin GNS430/530 can be bought that are TSO C145/146 compliant. Garmin are performing upgrades on existing GNS430/530s for $US1,500 right now, one of mine is booked in with the factory on April 16. At current exchange rates, a new TSO C145/146 GNS 430 costs less than AUD8,000.

As I've said before, when I can buy one from Garmin, the time for Australia to think seriosly about low level ADS-B might have arrived.

I don't work for Garmin.

[LeadSled]

SCE to Aux,
That's the -W models of the 430/530, but the upgrade of some older versions of the 430/530 seems to be a well kept secret amongst the local agents.
From Garmin
*Due to the TSO limitation in conjunction with the AFMS limitation, Garmin’s GNS 400/500 series navigators will not be certified as a "primary means" of GPS navigation until after customers install a new software version. Garmin expects to issue a Service Bulletin in the first quarter of 2007 issuing the software. The software will be updated via the 400/500W data loader card. This required software update is expected to be available in the first quarter of 2007.
**The AML STC data is intended to provide complete FAA approved data for a large subset of CAR3/FAR23 aircraft; however, if the aircraft does not pre-qualify for the AML STC standards, additional means of airworthiness approval will be required. End quote.
Translated _-- It ain't all peaches and cream.
Likewise, FreeFlight (was Trimble) have been threatening an upgrade board for the 2101 Approach variants, but I think they want to sell me new units.
Tootle pip!!

[onthedials]

Leadsled, thanks for the caution. I should take a dose of my own medicine. I am not entirely familiar with the "top end of town". I wondered how those units got on the list! To your list of GA C145/146 units, add the GIA-63W component of the G1000. The GIA-63 however is a C129a unit. Good luck with the Collins transponders. I bet there will be other similar stories before this affair is over. How good would it be if Microair succeed - but it makes no sense to agree to a national strategy and regulatory regime until we have some evidence that there is a market to support them.

My own view is that Australia is jumping the gun on ADS-B 1090ES for lower levels (by all means, let's have it above FL180, since the new airframes have it anyway and the airlines can gain a significant economic benefit). But I also think there is little to lose with continuing the GBAS and GRAS (differences acknowledged) work.

Quokka - no apology necessary. From where I sit, you've started something dangerously useful. Imagine (gee, I'm sounding like someone else) having an aviation discussion where the participants attempted to become informed as to the facts pertinent to the subject...

SCEtoAux - yes, your C145/146 Garmin 430W or 530W may well meet the navigation source data requirement of the NPRM, but what will you connect it to? I don't think you'll be connecting it to the widely-unannounced GTX33ES, since that is a blind device that needs the user interface of a G1000 or GNS 480. If you decide to hook it up to a KT 73 (the only real GA choice), please let us know how you go. My reading of the AC is that the cost of CAR 35 and related work in doing so would be a very costly exercise for a GA operator.

My main concern is that Australia is attempting to mandate standards and specifications before any real solution for GA exists. This is a bad basis for policy, because (1) the result is a distorted market for compliant product that may not be sold otherwise; and (2) in the cost-recovery environment, the regulator and service provider are effectively committing and spending other people's money for which they will never have to answer.

I think all of us in GA need to lift ourselves above the notion "that because my aircraft can do it, there is no reason why it should not be mandatory". Two warnings here: (1) it is easy to be disappointed when you discover that what looked good on paper won't work (say due to s/w or PCB revision) or will cost $10,000+ to test and certify; and (2) in the long-run, all of GA needs to be able to access the solution if we will ever see real benefits. The originator of this thread suddenly changed his tune when he discovered there might be a solution for his forthcoming Mustang after all. That's good for him, but no help to anyone else except the handful of GNS480 and G1000 owners in Australia. I'll leave it to others to figure out the true commitment to the public interest demonstrated by such an approach.

A serious technical discussion of all the implications of ADS-B, GBAS, GRAS and WAAS would be really worthwhile, but I think all of us (including me, Leadsled) should leave our baggage at the gate.

[gaunty]

onthedials

A serious discussion without polemic?? I agree

Most of the gear we operate is current whizbang technology, but we have recently ordered a brace of Garmin 530A's for retro to satisfy some Oceanic Nav requirements on some of the older aircraft that are "in transition" to the graveyard.

We are required sometimes to operate in some seriously third world conditions and belt and braces with handhelds as well are de rigeur.

It seems to me the sooner we can get the universal FANS going and if I recall it correctly ADSB was the foundation and cornerstone for it, the better. It might yet be Buck Rogers stuff but the thought of having an Australian controller riding shot gun in some of the more interesting areas to our North is comforting.

[Scurvy.D.Dog]

…. are there issues with the speed of ‘certification’ of ADS-B equipment? … particularly where it can be argued that any device (such as those mentioned in the TCAS thread) is surely better than nothing/none! … the solution must be cost effective to reach into the sectors you highlight (quite rightly) i.e. smaller aircraft

(1) the result is a distorted market for compliant product that may not be sold otherwise;

… is there any doubt about 1090ES as the international standard?? …

and (2) in the cost-recovery environment, the regulator and service provider are effectively committing and spending other people's money for which they will never have to answer.

… you lost me here!
.. The regulator and the service provider are still wholly within the Fed Gov’t (the Oz people) purview, by charter they are required to maintain a watching brief over risks to aviation! .. this obviously includes assessment of new (existing) and emerging technology, particularly where the improvement in collision risk mitigation is so large. The options for investment must be looked at very carefully!
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… it would be a very foolhardy organisation that:-
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- recommended public money be spent without thorough research, market knowledge, certainty and simplicity of regulation and;
- a funding solution
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... it would be equally foolhardy not to spend the public money if the cost/safety benefit clearly warranted it!.
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… an organisation owned by the public (gov’t) cannot spend any amount of public money without transparent justification, and quite properly so … and must definitely be able to account for it ... thank goodness the people own the revenue source than could pay for it!
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… the Gov’t must decide appropriate policy and expenditure .. if the numbers add-up .. they should have no reason to knock it back!
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- 100% subsidy for ‘out only’ boxes (poverty pack)
- Equivalent dollar subsidy for others (already equipped with gear to accept ‘in’)
- WAMLat (A, C, S, 1090ES) replacing MSSR and additional areas as required by A.S (CASR)
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.. how much?? .. who knows unless you know how much each box might cost!
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.. in the meantime ??
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.. who is paying who for GBAS or GRAS?

(1) it is easy to be disappointed when you discover that what looked good on paper won't work (say due to s/w or PCB revision)

.. s/w or PCB ??

[onthedials]

I should have explained more clearly.

"… is there any doubt about 1090ES as the international standard?? …"

Yes, unfortunately. The FAA has selected UAT for low level ADS-B in US airspace and not 1090ES, mainly because it wants it to be used to upload graphical weather products. As I mentioned in the earlier post, the Raytheon bid would change everything if it succeeds. The result would be much lower costs and greater choice in 1090ES GA products since the market volumes would not be split between 1090ES and UAT. My suggestion is that we wait to see which way the US goes before committing ourselves to subsidised products which may not turn out to be superior and in which aircraft owners may not have adequate choice.

Re cost recovery: I agree that expenditure is visible and transparent, as well it should be. My point is that it is easier under cost-recovery for the regulator at the behest of government to require all manner of things if it knows it will not need its minister to secure an appropriation. As an example, in 2005 the Senate Rural and Regional Affairs and Transport Committee asked why there were no appropriations to fund the minister’s promised additional radars. The answer was that the money would be spent over several years and that Airservices could choose to use funding from private equity markets. I should have chosen my words better – there is obviously scrutiny, but it is not the same as applies when all expenditure is funded by and subject to the appopriations process. You’re right – they would be very foolhardy not to properly research the matter before spending.

s/w = software
PCB = printed circuit board (hardware).
The revisions of these things (and even part numbers) within devices marked as the same “model” can vary widely. It is not uncommon for interdependencies to apply between the two, such as limitations on a software upgrade that exclude early hardware versions. I'm just cautioning that there may be expensive small print that should be thoroughly researched before assuming that equipment will interoperate or be upgradeable.

[LeadSled]

Folks,
A point I have made elsewhere, there are three(3), ICAO ADS-B standards.
So far unmentioned (unmentionable ??) is VDL-4. As far as I have been able to determine, VDL-4 is the only one of the three in daily used for actual ATC purposes at present, right now, at this time, as we speak --- as opposed to "trials", and that daily use is in Scandinavia. The "Mediterranean" trial is also VDL-4.
Most of the US trials, including all the work in Alaska, and all the United Parcel Service demonstrations of pilot managed approach sequencing, have been UAT. Right now, a big FAA UAT installation program is under way, it is going in across a number of the US eastern seaboard states. The whole value of the Alaska Capstone program was about the advantages of C145/146 GPS, moving maps and a broadband datalink, aircraft to aircraft "collision avoidance" was a relatively minor issue/bonus.
Most of the Northern European/CIS states have announced the adoption of VDL-4, whether it will happen is another thing altogether. How does that fit with Eurocontrol/ECAC ??--- it will keep an army of bureaucrats happy spending our ATC fees and large volumes of taxpayer's cubic Euros on busywork for years --- just like Galileo, really.
VDL-4 seems to be the market leader for on-airport ground collision avoidance, including the US, interestingly VDL-4 has been adopted by the US Marines as standard for its practice ranges, for tracking.
The good thing about ES1090 --- it's just an addition to a TXPD Mode S signal.
As all the Australian propaganda said/says, just a simple connection from a GPS (or FMCS) to a Mode S transponder --- remember the Airservices brochure for airlines, that showed a piece of wire and a 1.44 floppy for the software.
The bad thing about ES1090 --- it's just an addition to a TXPD Mode S signal.
With all the limitations of very restricted band width compared to UAT (~WBCDMA) and VDL-4 (more or less GSM 2.5), and only 4096 channels for the basic Mode A signal ---and --- (ask QF)--- the cheap, quick and easy retrofitting for airlines "ain't necessarily so".
Indeed hardly ever, unless the 747/744/767/757/737/add long DC/MD list was ES1090 capable ex-factory. Early (less than the last several years delivery) Airbus, I don't know, but I rather suspect the same, retrofitting ES1090 is very expensive (complete recertification of a new FMCS/ADC fit) and hard to justify in an older aircraft -- and that just for ADS-B "out". Integrating ADS-B "in" with TCAS 11 is a whole new ballgame, again unless it was delivered ex-factory ---- Unless the aircraft are really old, where all the avionics are separate boxes, like most GA aircraft, just update the boxes, a bucket of $$$ for the STC, $0.25M for a 100/200/300 B747 or other "707 vintage" stuff.
ES1090 will never cut it for ground collision avoidance as is being proposed.
As for Raytheon's proposal to dump UAT ---- Mitre Corp. (FAA) will probably have something to say about that, because of the "The bad thing --" above, particularly the 4096 limitation. Given the number of aircraft in US (and airport vehicles) it wouldn't be too hard to see more than 4096 transceivers in line of sight.
Tootle pip!!

[Quokka]

...and your vote is for...?

...so... UAT or VDL-4?

[Scurvy.D.Dog]

A point I have made elsewhere, there are three(3), ICAO ADS-B standards.
So far unmentioned (unmentionable ??) is VDL-4. As far as I have been able to determine, VDL-4 is the only one of the three in daily used for actual ATC purposes at present, right now, at this time, as we speak --- as opposed to "trials", and that daily use is in Scandinavia. The "Mediterranean" trial is also VDL-4.

… not quite, 1090ES is being used in Oz by ATC (for the majority of Turbo-jet RPT who are equipped), the only impediment to 5nm surveillance standards is dual path data commissioning (not far away)!

Most of the US trials, including all the work in Alaska, and all the United Parcel Service demonstrations of pilot managed approach sequencing, have been UAT. Right now, a big FAA UAT installation program is under way, it is going in across a number of the US eastern seaboard states.

.. I must have missed something here, as the latest info available on their website http://www.adsb.gov/docs_10-27/brief...kage_10-27.pdf has the ‘final’ segment (remainder of segment 1 and 2) decision in July 07’

The whole value of the Alaska Capstone program was about the advantages of C145/146 GPS, moving maps and a broadband datalink, aircraft to aircraft "collision avoidance" was a relatively minor issue/bonus.

.. yeh daft eh! .. the biggest single benefit??

Most of the Northern European/CIS states have announced the adoption of VDL-4, whether it will happen is another thing altogether. How does that fit with Eurocontrol/ECAC ??--- it will keep an army of bureaucrats happy spending our ATC fees and large volumes of taxpayer's cubic Euros on busywork for years --- just like Galileo, really.

… whoah .. ya gunna have to explain that sweeping statement a bit .. which northern European states and was that before or after the bandwidth issues with 1090ES were addressed???

VDL-4 seems to be the market leader for on-airport ground collision avoidance, including the US, interestingly VDL-4 has been adopted by the US Marines as standard for its practice ranges, for tracking.

.. thats fine and beaut on a MIL range where the other bits like compatibility with other users is well not so important

The good thing about ES1090 --- it's just an addition to a TXPD Mode S signal.

.... and it does not require dual signal and/or rebroadcast like UAT and VDL4 ….. less complexity, less cost (particularly to GA)

As all the Australian propaganda said/says, just a simple connection from a GPS (or FMCS) to a Mode S transponder --- remember the Airservices brochure for airlines, that showed a piece of wire and a 1.44 floppy for the software.
The bad thing about ES1090 --- it's just an addition to a TXPD Mode S signal.

.. depends on your definition of bad! …. simplicity and compatibility with existing TXPDRS .. what’s not to like? .. the other datalink stuff the yanks want to uplift via UAT is range limited, requires dual band, rebroadcast therefore redundancy .. why is that better than Satellite for the other data (WX, NOTAM and other bits) whilst retaining 100% single band compatibility for all types for traffic (lots of which already have ES)

With all the limitations of very restricted band width compared to UAT (~WBCDMA) and VDL-4 (more or less GSM 2.5),

.. again ES is single band, augmented (for those who want the other stuff like WX) with Sat (no range issues) ….. is wider bandwidth of UAT or VDL4 worth the carriage of dual bands, not to mention range limits to ground stations for all the ‘other stuff’ (very pertinent in the outback Oz)

and only 4096 channels for the basic Mode A signal ---and --- (ask QF)--- the cheap, quick and easy retrofitting for airlines "ain't necessarily so".

.. the efficiencies available to highfliers of having the gear (software, cable etc) V’s procedural separation standards in remote areas …. Comon

Indeed hardly ever, unless the 747/744/767/757/737/add long DC/MD list was ES1090 capable ex-factory.

as far as I am aware (stand to be corrected though) most all VB and QF 738’s, JST A320 have it, not sure about B717’s in the west … in any event, that is what WAMLat is going to (in part) address (existing TXPDRS)

Early (less than the last several years delivery) Airbus, I don't know, but I rather suspect the same, retrofitting ES1090 is very expensive (complete recertification of a new FMCS/ADC fit) and hard to justify in an older aircraft

.. not that I don’t believe you, but have you got something tangible that supports the statement?

-- and that just for ADS-B "out". Integrating ADS-B "in" with TCAS 11 is a whole new ballgame, again unless it was delivered ex-factory ----

.. so are you say that the FMCS in a VB B737 is sufficiently different from that of a VB B738 that requires a ‘recertification’ as you put it?

Unless the aircraft are really old, where all the avionics are separate boxes, like most GA aircraft, just update the boxes, a bucket of $$$ for the STC, $0.25M for a 100/200/300 B747 or other "707 vintage" stuff.

… wouldn’t the STC be common to type?? .. economies of scale and all that?

ES1090 will never cut it for ground collision avoidance as is being proposed.

rubbish, Multilat with A/C/ES …. See http://astra.aero/downloads/ABIT/ABI...Comparison.pdf

As for Raytheon's proposal to dump UAT ---- Mitre Corp. (FAA) will probably have something to say about that, because of the "The bad thing --" above, particularly the 4096 limitation.

.. are you suggesting ES out will also be limited to 4096 codes?? .. common Lead, you know the ADS-B we are talking about has 24 bit addressing .. how many codes is that ??

Given the number of aircraft in US (and airport vehicles) it wouldn't be too hard to see more than 4096 transceivers in line of sight.

…. As stated, ADS-B ES has a code allocated to the specific aircraft/box, these codes are many digits long! … if I have this wrong could you point to a reference!
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Below is the latest link page from the Australian ‘propaganda’ as Leadsled calls it:-
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http://astra.aero/ABIT/index.aspx ..comparisons of systems and other costing data etc
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And for those that missed the stuff from Europe:-
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http://www.pprune.org/forums/showpos...&postcount=178
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Poodle Tip!

[LeadSled]

Scurvy, Old Dog,
My dear chap, most of what I have drawn attention to is actually available on the links you so helpfully previously posted and reposted here.
Having a Mode S transponder is a long, long way from having ADS-B.
As to the ramifications of 4096 codes limitation, I defer to the opinions of the Mitre Corp. http://www.mitre.org/.
As to multi-lateration for ground collision avoidance, whether the positional accuracy will be good enough is an open question, quite apart from the 4096 issue.
The only other comment I will make is that the "ASTRA Cross Industry Business Case", (or whatever it is precisely called) does not qualify, even in the most generous definition of a cost/benefit analysis, as a cost/benefit analysis, let alone a "business case". Also have a look at the CASA efforts on the subject, it will tell you a lot.
In fact, I will make one other comment, there is far to much "faith" in something called ADS-B, and not nearly enough fact ---- until you get to the senior level bean counters at several well know local airlines --- where demonstrated competence in simple accounting arithmetic is a job requirement.
Tootle pip !!

[onthedials]

I wonder if ATC systems can operate without a Mode A 4096 code (or pseudo code for Mode S) to associate a target with flight details. Does anyone know if that happens now (anywhere)? Presumably the REG/ field in Australian flight notifications could be used to associate the Mode S address with the flight plan in addition to, or instead of a code.

[the wizard of auz]

Ever had a satellite or three drop-out in your GPS? How many times has a GPSRNAV aircraft lost RAIM? All it takes is a CB in a direct line between your aircraft and that equatorial satellite on Final, in IMC and...

very rarely........ but I guess you just hit the GA button and follow the published procedure, go and hold for ten mins and try again..... pretty accommodating things them cells......pretty predictable lifespan.

[bushy]

Sunspots?

There has been some suggestion that sunspots may affect GPS.
Sunspots definitely affect HF radio at times, as they affect the ionosphere, and HF radio depends on the waves being reflected by the ionosphere. I have never heard of a case of VHF or UHF waves being affected by sunspot activity, as they are direct, line of sight, with no reflections.

[GaryGnu]

Flight Plan Coupling with ADS-B

Onthedials,
Yes ATC can couple the FLTID obtained from ADS-B to the flight plan.
For more see here

There is no need for Mode A SSR Codes

[onthedials]

GaryGnu, thanks very much. That's very helpful - and most encouraging. Like so many things AsA does (at least from where I sit), there is clearly a professional, measured and responsible approach being taken to its introduction, which does the organisation great credit. Maybe I'm missing something, but it's hard to see how the Mode A four octal digit limit could have any significance for ADS-B 1090ES in Australia.

Leadsled, I searched Mitre's site and could not come up with any specific reference to the Mode A address space limitation as an issue for implementing 1090ES in Australia in normal circumstances. From casual reading, I understand that (some? all?) US radars dump the FLTID parameter and that it does not make it through to their FDP system. Clearly that doesn't happen here with Eurocats. If you have them, I'd be interested to read any specific references to Mitre's concerns in this area...

[Creampuff]

Leaddy this is thread, Leaddy this is thread, do you read?

[LeadSled]

Creamy, old mate,
Now I do, I've just been tied up (not literally) with a bunch of your ilk, trying to persuade another bunch of similarly professionally engaged, that the third party, well know on this site, is wrong. Decision reserved.
Onthedials,
Sadly, Australian aviation is so small, that 4096 codes will not be an issue in Australia. It was a consideration for FAA, in going UAT v. VDL-4, and then handling dual, maybe triple, airborne systems.
I was really directing attention to the proposal of one of three FAA NGATS respondents to dump UAT, in favour of GA aircraft having to buy a separate datalink for "data" --- where it doesn't have any patents to exploit by going along with UAT --- Universal Access Transceiver ---- so lets take a technological leap backwards, go for an old and developmentally limited system, and scrap the already extensive ground and airborne investment in (relatively) new technology UAT.
FAA have announced that FAA/Mitre Corp. will examine the ramifications of the proposal to dump UAT--- ie; Why has anything changed since the original decision that FAA needed the dual system --- Including the future potential of the Universal Access Transceiver architecture (or VDL-X, for that matter) --- in favour of a minor and "limited in potential" adaption of a piece of 30/40 year old avionics --- was "cutting edge" in the mid-20th Century --- with the emphasis on limited--- very.
Tootle pip!!!

[gaunty]

LeadSled

And your point is?

OK so us dummies are suitably impressed with the slick polemics and how you are a card carrying member of the inner sanctum passing down recieved wisdom, but you may better employ your time here emulating our friend Ockham.