Garfly

Ahhh ... okay, got it now. Thanks for the patient explanation.

Aro, you are misinformed. ADSB works aircraft to aircraft. There is no significant latency due to a 'similar logic' to internet based traffic displays. Nobody here thinks it's magic. It's science. We agree on one thing, though, "understanding the limitations is the key to improving safety rather than degrading safety."

I don't think I understand the point you're making Aro. I'd have thought that a threat approaching close enough for separation to be an issue would go on the useful side of the ledger. What if you're in a high wing and the airprox target is a low wing descending on you from behind, a glance at your iPad screen (as into your rear vision mirror) might be the ONLY thing standing between you and disaster. What's the point of looking outside if you don't know where to look; if the other aircraft is, at that moment, invisible to the eye, for whatever reasons. I've probably experienced a half-dozen unexpected close encounters with other aircraft over the years and in each case the threat emerged out of the blue yonder in a matter of seconds and had whizzed past before any kind of reaction was even thinkable. And you can find dozens of real-life, close-call videos online that all tell exactly the same story. Which, BTW, is why I've always thought of the "clearing turn" as one of aviation's most fervent Hail Marys. It's often done as a ritual, as if just performing it will give some kind of magical protection - never mind that it was done 5 minutes ago and that jet bearing down on your stall practice has travelled 20 miles since the last, ahem, 'clearing'. Also, I don't get the difficulty that you seem to see with "self-separation ... because when you are in reality a long way apart any change to your track doesn't make much difference on the screen." In my experience you can easily judge quite small deviations. ADSB updates every second or so and any threat icon will have a little arrow showing its current direction (plus altitude and vertical trend) and you own ship icon has a longish pointer line indicating clearly where you're headed. The whole situation can be grasped in seconds from the picture on the screen (far better, quicker, safer SA than the best radio chat has to offer.) And I don't see a problem with threat targets not sticking to straight lines. A mere glance updates the danger just as it does with the big semi bearing down on you in the rear view mirror. You see. You avoid. Anyway, you give a good example of all that from your own experience: "yesterday I was inbound to an airfield about 20 miles out when another aircraft departed on a reciprocal track. I was able to delay my descent until we passed each other so I wasn't descending into their path." For sure, there are down-sides to all 'simple solutions' it's just that I haven't come across the same ones you have with SE2, in practice. Of course, the problem remains that the majority of the GA/RA fleet are not ADSB equipped. But that's changing slowly and, anyway, just being able to see and avoid RPTs and flying doctors, alone is definitely worth the price of admission. Anyway, in an earlier post I quoted from the ATSB Mangalore report, thus: "Had each aircraft been fitted with ADS-B IN, and a suitable cockpit display, the occupants would have received the same quality of surveillance information received by the controller. This technology could have prevented this accident from occurring ... // The ATSB also notes that ADS‑B receivers, suitable for use on aircraft operating under both the instrument or visual flight rules, are currently available within Australia at low cost and can be used in aircraft without any additional regulatory approval or expense." And you said about that: Again, I'm not quite sure where you're coming from here. It seems to me you are reading too much into the report. Or perhaps into my juxtaposition of those few selective quotes. Of course, IFR ops in general have little to do with us recreational types. Anyway, I took those passages in the report to suggest that although those aircraft were on IFR plans they were effectively operating in VFR conditions - they would have been cleared to descend into the badlands of G space, I presume. Just like very many commercial flights do every day. These are places where aircraft on IFR plans - but in VMC - need to arrange their own separation from the hoi polloi - and from each other. This is still - for good reasons - done mostly by radio but I think the writers of that report were just moved to point out that even the most basic sub-1K SkyEcho box hooked up to the iPads in the cockpits of those two twins "could have prevented this accident from occurring ..." They were not trying to say that ADSB IN/OUT was all that was needed for IFR self separation. And the UAvionix company very clearly states that the SkyEcho2 is provided ONLY as an aid to traffic awareness by VFR pilots in VMC. IFR and IMC have nothing to do with it.

Yes, and even aural alert functionality running EFBs with AvTraffic https://avtraffic.com/# But I think RFguy's experiments aim to take all that to another level. To quote him: "... yeah it's easy enough to do a proximity alert with gps XYZ available ... // ... future motion can be described with a simple set of equations like new location = old location + velocity and direction. One second is a pretty good update rate so it doesn't have to guess much, just project a trajectory. As an object gets closer, it's worthwhile making the algorithm leaky, such that older fix points are weighted lower in the prediction, and the most recent updates weight more heavily. // ... essentially - how it works 1) Acquire time series location data (from ADSB receiver from other aircraft) 2) apply a Kalman filter to that data to get the most likely values- since the raw location data from the ADSB probably has a random magnitude of 5m in XY and 10m in Z. 3) Now we have cleaned data, apply the data to a non linear regression prediction tool . There are many - and quite sophisticated tools and algorithms. 4) predictions are done, paths drawn in 3d space, and for each combination of airplanes, distances calculated as a time series to provide a probability of a conflict Think of the use of a Kalman filter as a zero lag averaging tool."

(We already have our own smart guy on the job ;- )

Yes, and I guess the AV-30C (which is an installed PFD instrument) is also plumbed into the aircraft's pitot static system. The SkyEcho2 is measuring its Pressure Altitude from the cabin where it's mounted and that can vary - even in basic aeroplanes - from static port values. So there's another possible error right there. But we're not using the device to 'just-miss' conflicting traffic vertically in IMC. And, in any case, all indications are rounded to the nearest 100'. Whenever unknown traffic shows up on the screen with 00X relative altitude (i.e less than 1000') I reckon it's time for a good look outside in the indicated direction. (To me the 00 stands for "Uh, Oh!" ;- )

I believe that all ADSB altitude encoders (like Mode C) work on the basis of Pressure Alt. - effectively, Flight Level -so that all aircraft are on the same pressure datum (necessary for self separation by cockpit display). This would typically vary by several hundred feet from AMSL values. I've read that ATC automatically correct the PA values for QNH below the transition level and that this is partly why controllers routinely check on the correction by requiring pilots to report altitude. Maybe some of our ATC people could confirm and/or enlighten us on this point.

Say what?! The report says it was an accident on takeoff. Newly qualified pilots shouldn't take off over water?? Nothing 'straightforward' here but the tendency to blame fellow pilots right off the bat.

https://en.wikipedia.org/wiki/Fairchild_XC-120_Packplane

By the way, when it comes to FLARM and ADSB (at least in the UK context) it's not necessarily an either/or situation. https://flyer.co.uk/flarm-and-uavionix-to-collaborate-on-electronic-conspicuity/

Yes, but ... getting our facts straight on such matters is pretty desirable. And falsely dissing the benefits of ADSB IN-OUT / SE2 is, to say the least, counter to current safety messaging. In its report on the tragic collision of two light-twins over Mangalore in early 2020, The ATSB observed: "Had each aircraft been fitted with ADS-B IN, and a suitable cockpit display, the occupants would have received the same quality of surveillance information received by the controller. This technology could have prevented this accident from occurring ... // The ATSB also notes that ADS‑B receivers, suitable for use on aircraft operating under both the instrument or visual flight rules, are currently available within Australia at low cost and can be used in aircraft without any additional regulatory approval or expense." https://www.atsb.gov.au/publications/investigation_reports/2020/aair/ao-2020-012

This is not correct. SE2 will indicate exactly where other ADSB targets are relative to your own ship vertically and horizontally, and in real time. It will also show whether it is climbing, descending or level plus it's speed and direction. You might be confusing it with a cell based system like FR24 (and even they do way better than a "5 minute window".

I find, while driving off the beaten track, the 250K Topo (AU) map in OzRwys to be a very useful nav tool. Most bush tracks (on which signposts are scarce) seem to be on it - where they belong. And, since the whole country's already downloaded onto the phone, there's no need to be within internet range. I know there are proper downloadable 4WD map apps but, short of one of those, I find my trusty EFB real handy for terrestrial nav as well. (Though, down in the weeds, I take its suggestions re DTG, ETA, ETE etc., with an even bigger grain of salt, and "You Are Here" is all I need to hear! ;- )

An update from Juan:

Yep, it's not for nothin' they built a statue to Eros smack dab in the middle of old London town.

Fair enough OME, and as old mate Hamlet said to his mate Horatio "The best safety lies in fear." Which is why I reckon old Arthur Butler would have been as pleased as punch to have a working iPad with him on that flight. Good on him for his courage, though, in doing without. ;- )

Very true, ditto the whiz-wheel and official forecasts. Having used iPads for yonks, though, I've not, myself, found any internal GPS to be out by more than a few metres, given a fair crack at the sky. But yeah, in aviation, it has to be a trust-but-verify relationship with tech stuff (like with engines, airframes and the old whiskey compass).

You'd also be sorry if you returned to old-school virtue but then mistook town A on the WAC for town B on the earth (so similar!!) and found y'self on some track winding back to an old fashioned shack. Or, if say, those headphones up on the dash caused that compass 'thing' to fail (throwing it out, say, another 60 degrees ... on top of its usual 30) and you end up camping on desert dunes when you'd come all prepared for the beach. Oh, aye, them were the days. I think I do repeat myself (LOL) but I'm sure there were Old Man Seadogs, in days of yore, who reckoned those new fangled magnetic loadstones were a curse; what, with all their stupid "You're sailing in this direction" stuff. Heaven's above, sure it be a far more honest thing for a mariner to watch the waves and stars (so long as they be out tonight, mind) and to heed their ancient wisdom "You've got this new world to find. Look for it." Anyway, regarding those modern screen things and their incessant "You are here" stuff: heck! that ain't the half of it, they're total chatterboxes nowadays: it's all "Your TRK is this, your BRG is that, your ETA is this, your ETE is something else, your GS is XXY kts, the wind aloft is ZXY/X0, the CTA step above you is at AOZY, your current FIA freq. is XX0.XY and, by the way, here's the next one you can dial in right now. The current DA is X000', Last Light will be at YY30 hours and, in case you're interested your present Height Above Ground is only XX'. If you're worried, your nearest suitable airfield is YY.0nm distant on the XYZ radial with an elevation of X,YZX'. Fuel required for that diversion will be ZZ litres. Your GPS altitude is currently X,500' and your barometric is 200' lower. All terrain that might be a threat is now coloured red. This is your Grid LSALT just to be safe. The current Area QNH is XXXX hectopascals. You will notice that all active PRDs, too, on your route are shaded red. They will change in real time so keep an eye out in case you decide to take that short cut if that Romeo is deactivated. Those CBs you were worried about are, as you can see, now moving away from your route. Oh, and by the way, since you've finally bought a SkyEcho2 you will notice that, at present, you have no conflict with that RPT heading for our same DEST. So just relax a little. And now, well whaddaya know? ... your ETE has now reduced to just X minutes. So nice flying with you, Capt." Sheesh! No wonder there's so much nostalgia for those 'Oh, so peaceful' days of paper, clock and compass. But notwithstanding all of that - and despite the many rumours of heads-down screen-fanatics - I do declare I've never been more heads-up on trips since I stopped struggling with paper charts which never did learn to tell me simply "You Are Here".

I believe his formation buddies were over to his left. If he was being asked to formate on them he had a right to expect the organisers to look after the airspace to allow that. You can't fly formation and dodge traffic at the same time, or even look for any.

Fair enough, SP, but just taking a look at the new WACs, I can see there are remote parts (e.g 50nm NE of Alice, just beyond the YBAS VTC) where wee Romeos might pop up out of nowhere (ones the feds might be serious about ;- ). So, in such cases and places, one'd probably do well to use the new WACs. They're pretty uncluttered out there anyway. If you're on paper only, though, and you haven't planned with such unlikely no-go's in mind (or you're on a diversion, due whatever) the new WACs will warn you off but won't tell you much more than the PRDs name and boundaries. They won't say, for example, if it's only NOTAM activated or to what flight levels it applies - in the way that VNCs and VTCs do. (There should be a quick look-up-by-number function so that all PRD details can be gotten on the spot - when Capt. Google is out of the cockpit.) Anyway, if you do a long-press on any spot on your OzRwys map-screen you will bring up a list of all airspaces overlying that position. In this case we can at least discover that R235, in fact, applies from SFC to FL070. (I'm assuming that this list is drawn from the app's database downloaded to the device and thus available anywhere.) CLICK ON IMAGES FOR HIGHER REZ.

Sure, being that close, formation flying, in fact, even pro-tech guys (like m'self ;- ) would say your eyes would HAVE to be outside. But even if you had aural warnings available you'd have to turn them off during an airshow, they'd be going beserk.

I guess that even if they'd had time to glance at their traffic displays they'd have been expecting to have a bunch of other aircraft buzzing around very close, anyway. (No time for a "but not that close!" thought to be thunk, let alone acted on). We do know that both ADSB-OUT devices were on since we've seen their flight paths displayed and discussed on several of the video reports.

Well, with today's AIRAC 2212 Updates for OzRwys (and AvPlan?) we now have - for better and for worse - PRDs marked on our EFB WACs. I'd say it's worse for the busier regions because all that magenta just adds clutter, obscures detail and gets your course line lost in a magenta jungle. Sure, for the most part, you'd be using VNCs and VTCs anyway, so it doesn't matter that much. But I've found that having at least one aeronautical chart devoted entirely to geographical realities has been a good thing. (Given that other charts, just a click away, have all the airspace info anyway. And, for that matter, the EFB can be set up to display active PRDs as a layer onto any chart. (With the catch that you need to be in internet range to get those real time updates.) But, yes, it's a lot better for remote areas because, as pointed out above, in the absence of the large scale charts, the marked PRD borders are not redundant but necessary. These new WACs in their paper form, will, I gather, be printed kind of on-demand, because they will now be going out of date with as much regularity as all the other airspace documentation. Therefore, to be legal, remote paper-chart users will have to keep a close eye on all PRD updates. (And I presume that pencilling in the changes won't cut it anymore. ;- ) CLICK IMAGES FOR HIGHER REZ.

They're plenty well qualified but not well supported by the establishment in the investigative role. I'd have thought that most, if not all, lessons learned investigating an RAAus accident would be applicable to GA. Furthermore, the Ballina airprox incident, alone, shows that all flying machines are inter-locking parts of the one sky-safety system. It's foolish to regard the RAAus sector as Sunday drivers who can be dismissed and set aside. From the RAAus website: Who are RAAus Accident Consultants (ACs)? Accident Consultants (ACs) are typically RAAus employees who are requested to assist at accident sites. ACs who are employees of RAAus are required to complete the ATSB Accident Investigation Training, or an equivalent course, to formalise their qualifications. RAAus is also supported by other subject matter experts and the ATSB. https://members.raa.asn.au/safety/fatal-accident-investigation-process/?