BASI "Limitations of See & Avoid" ??

[Niles Crane]

After a number of years, I have just re-read the 1991 BASI report on See and Avoid.

A number of people have ridiculed this report in previous posts and I am wondering what the objections are?

To me it makes very good arguments for the scrapping of NAS as NAS uses "unalerted see and avoid" as the primary means of risk mitigation.

But then I am just a Profesional Pilot, not a Private Pilot!

As see and avoid is the primary mitigation for collision avoidance in "G" airspace, how can an IFR pilot comply with Jepp page ATC AU-714, 5.4 especially 5.4.2(d).

CASA requires a pilot to put his/her head into paperwork at the exact time they should be looking out the window, for a piece of useless information (TAAATS knows all this anyway). A pilot should just be able to say: "departed this time, tracking ...... climbing .....".

Of course Open Mike and the electronic person only care about the private end of town and nothing about pilot work load etc that the NAS imposes on IFR types!!

[Capt Snooze]

Niles,

Is there a link to that report?



Snooze

[NOtimTAMs]

The above may be a wind-up, but here goes....

Niles,

What's the problem?

IFR flights have been climbing and descending through the levels of VFR flights in class G for years. There has never been any serious alerted see and avoid in this - many IFR ACFT at TOD or altitude change just make a call to Centre for IFR traffic, not all make a location/atitude/intentions call - and even if they did, at many locations conflicting traffic may not hear it because they are on an adjacent Area frequency (e.g. descent into Mudgee from the south)or they just hadn't changed from their last frequency yet. I am not aware of midairs occurring in Australia because of this.

I don't use Jepps, but what paperwork are you referring to? Is it the estimate for next reporting point? Just give a value based at departure time plus flight planned estimate and correct it en-route. Simple. No need for fancy calculations on climbout through the more populated CTAF/MBZ and lower levels of G. If you really don't want to do any math, just get one of them new-fangled GPS thingies TSO'ed and otherwise (the Garmin III Pilot is great for instant multiple en-route estimates once in cruise - even betterthan the GNS 430 for this purpose!!).

BTW, IFR flying is not just the domain of paid pilots - many folks with CIRs who are fond of living and returning home to their families fly carefully and responsibly for business, as private ops.

Personally, I'm not particularly fond of NAS - it seems unnecessary change without justification - no-one has come up with convincing explanations of the proposed cost savings....but we're fooling ourselves if we think IFR ops in class G are really any more protected now than they will be under NAS. Roll on ADS-B!

Safe flying:ok:

NOtimTAMs

[Manwell]

Dear Niles,

If you can't recognise the flaws in the BASI report then you may be either too myopic to fly an aircraft using the picture in the window, or too indoctrinated into basic IF to understand how one can fly an aircraft and look out the window at the same time!

If you wish to achieve enlightenment, try flying aero's from the back seat of a tandem taildragger - no instruments - then you might actually become a really good instrument pilot.

The frustrating thing for me about the CASA push to See and Avoid is that it was purely political. Before, when it was in their interest to push the line that See and Avoid was dodgy, (as justification for ATC mostly) they did so. Trying to convince young pilots of the stupidity of the argument fell on deaf ears.

Now, we've got TCAS. Still no need for airline pilots to look out the Goddamn window.

Did you not find it interesting to note that the report states that private VFR pilots typically spent about 50% of the time looking out, while airline pilots spent about 20% of the time scanning outside? Who sounds the more professional to you Niles? The guys with all the automation and gear in a multi-crew jet or turbo-prop, or the poor old VFR Bloggs doing his best to get there alive?

By the way Bloggs, I'm not a Private Pilot, I'm just speaking the truth as anyone will discover for themselves if they think it through thoroughly.

Mate, if the BASI report was correct, how the hell would you have survived so long before even getting into an aircraft?

Prove all things, hold fast that which is good....

[Captain Custard]

Tim Tams,
You're wrong. Many IFR aircraft have been climbing thru VFR who have been on the radio above 500ft (it's the LAW), and it is also the law that IFR make a broadcast for the benefit of VFR BEFORE leaving CTA. Where I fly, it happens. I suggest that if "many IFR only make a call for traffic, not all make a location/atitude/intentions call" then they are bloody-well breaking the rules.

Your quip about the estimates is also a furphy: with any GPS, unless it's a full blown FMS (aka >US $80k), it WON'T calculate the correct estimate after takeoff, and level, in the cruise, is too late! Besides, why do you say "just add the dep time to the flight planned estimate and correct later". That is exactly the maths that Niles is talking about!

You can forget ADS-B too: are you going to fork out $20k just to avoid me? Can you imagine the Hamiltons and the Smiths of the GA world doing that?? Keep dreaming, lad. The aluminium that's going to kill me and my pax will be the VFR cowboy ripping around in E with his radio off, or worse in the "CTAF" listening to Triple M, not my IFR compatriot. They (the VFRs) are hardly likely to want to put in ADS-B eh? The current system is as safe as it needs to be for IFR vs IFR and affords far more flexibility than this E junk (provided that the rebro is turned off!!).

Manwell,
When was the last time you were in a two-crew jet trying to lookout as well as manage the machine?

1991 was the year of the report, but other excellent articles by BASI on the folly of unalerted See and Avoid appeared in "Asia Pacific Air Safety" of March 98 and Sept 98 (before DS decided that BASI were too recalcitrant and combined the mag with the CASA propaganda rag, Flight Safety Australia). Sorry, no links could be found.

[Chimbu chuckles]

Manwell

The 50%/20% stat....does that make allowances for the fact that at FL 370 there's not a lot worth looking out the window at?

Believe me, when a jet is sharing airspace with VFR/Lighty traffic two pairs of eyes are on full swivel.

The fact remains that in modern aircraft at the speeds we travel at See and Avoid is a joke except as an absolute last line of defence. It is an annacronistic hang over from the early days of aviation being used for cynical political purposes by people I wouldn't trust with a kite!

Chuck.

[BrianG]

Manwell,

Why the need to slur Niles or his flying ability? Do you actually know anything about Niles' flying experience/competency/knowledge?

IMHO, too many people on PPRUNE seem to think that if they put down another persons flying/techincal ability their opinions somehow carry more weight than the person they have put down. Play the ball, not the man.

[NOtimTAMs]

CC -

I hope that it's actually the LAW that radios are carried by suitable ACFT above *5000* feet. Of course, gliders are not required to, for example.......I'm also pleased that you have perhaps the luxury of flying in "protected airspace" - it's still not as protected as you think. Perhaps unlike you, there are many folks whose aircraft don't have the performance to stay in CTA at al times.

I'm pleased that you are making the correct calls out of CTA. There's many a call I hear from ACFT in the radar J-curve who are perhaps lulled into complacency by being identified who merely identify a change of level or "ready for descent " or "on descent", and many calls that state they will join way point "echo alpha" for a GPS NPA for aerodrome X (menaingless for anyone who doesn't have there plates out and completely useless for VFR pilots)......that's not alerted see and avoid. And even IF all the "correct" calls are made, there are many places where potential conflicting aircraft at area boundaries will not have heard your call - what are you going to do, mandate calls on up to 3 or for adjacent area frequencies for all potential conflicting traffic?

As for jet and high performance aircraft operating on unalaerted see and avoid - despite the NOTAMs that proclaim large areas of Australia as danger areas for crossing low jet traffic, life still seems to go on as normal on the military LJRs.....

Nonetheless, I still maintain that IFR aircraft OCTA have been crossing VFR levels on unalerted see and avoid for years. Whilst radio procedures may have helped in terminal areas, and while see and avoid I also agree has important limitations, for en-route ACFT below the pressurized levels the big sky probably has had a lot to do with the lack of mid-airs.

Again, estimates for next reporting point en-route - as Niles says, TAAATS has a profile that the ASA folks seen happy to work with, the pilot in command has calculated estimates or intervals for all en-route reporting points taking into account winds/climb speeds, the pilot knows his departure time - I can't see where your problem is. I don't know too many places where I have to give an estimate for a position that I will still be climbing out over, and if I do, again GS from DME or GPS will be sufficient for a quick bit of mental calculation......don't need no FMS. If you're climbing out on a complex SID from a major airport, you're on radar...... I've never needed heads-down for an estimate. If you're too busy flying the plane, "stand-by" is a perfectly acceptable response.

ADS-B - I know, I know, tell me I'm dreamin'. Still be cheaper to distribute these than maintaining/overhauling all those SSR sites, eh?

Again, I'm sick of the VFR bashing - you can fly safely under both sets of rules, and not everyone has the luxury of flying pressurised or jet/turboprop ACFT....or the luxury of 2-crew operations. It's not "US" and "THEM" - we've been co-existing and piots have been crossing over to fly under both sets of rules for years.

Safe flying :ok:

[Niles Crane]

NOtimTAMS

Good to hear some logical argument. The debate will go on....

You may be sick of the VFR bashing, but this whole NAS is IFR bashing with regulatory approval and the only force behind IFR is QF. But QF is only interested in itself!!!

I cannot see why the travelling public has to put up with a system that only benefits the private pilot and "bug smashers". Its like allowing fringe medical practitioners to conduct surgury in hospitals, the public would be in uproar.

[DickyBaby]

All right, I'd be the first to admit I don't have a pilot's licence and therefore shouldn't be entitled to an opinion on procedures out in the GAFA but I have heard tell many a tale of sweaty-palmed arrivals at Mudgee, or Dubbo for that matter.

SOP for aircraft that don't transfer to the correct frequency for one reason or another is for ATC to make a broadcast on your behalf. If you're going from one area frequency straight to CTAF then we'll pass traffic to all inbound IFRs and any VFRs we know about. Still doesn't cover all contingencies but it's still better than nothing at all which is what some people believe we're doing now.

Be a bluddy good job if wasn't for all these pilots asking for stuff all the time...

[Manwell]

BrianG,

Hmmm. I really tried not to personally vent my frustration on Mr Niles. No, I don't know his ability level, however it did seem that he had the same problem that I've found has afflicted other pilots, not all of them low time.

Perhaps he is experienced, if so, I am sorry. Experience should really help him to understand the reality of this issue. Perhaps you are experienced? If so, do you not understand the truth about see and avoid?

Noticed how the military seem to manage to survive from day to day despite their very low level and very high speed type of operation? How is it possible for the military to avoid objects at 660kts odd? Bit quicker than your 300kt climbout in a 73 and you don't have the benefit of radar keeping everything out of your way.

I believe that radar was dreamt up to enable pilots to come close enough to another aircraft so they could see them. Nowadays, the purpose is reversed. Even so, the NAS is being introduced so that we can grow up. We don't have to feel that we need ATC holding our hand whenever we venture skyward. We are big boys now. I'm really not being sarcastic now BrianG, this is true.
We will eventually have to come to the realization that our eyesight is really not as bad as BASI would have had us believe.
It works in the US. Think of the maths in that assertion.

SAME AREA, MANY MORE A/C, WORSE WEATHER, WORSE TERRAIN, ACCIDENT RATE ABOUT THE SAME OR LESS. Better Pilots? I hope not!

The closest I've come to a mid-air was in CTA! And this after operating for a few years in the BK training area, the busiest airspace in OZ.

The fact is that this country is bloody big. Try working out the mathematical probability of two aircraft being in the same airspace at the same altitude at the same time, even within one nm cubed, and you might just understand.

Reminds me of the mythical character who was implored to jump off a high cliff. After much protesting he was pushed. And he flew. We can fly too boys and girls...

[NOtimTAMs]

Dicky Baby

Glad to get an ATC view. Don't worry about not being a qualified pilot - my pax say it's never worried them! ;) ;)

Didn't know that the broadcast on behalf was SOP for info for VFR as well as IFR acft. Is this workload permitting or a required action? What level of discrimination (i.e. 1, 2, 5, 10 NM) do you reliably get from SSR returns in the GAFA? Unless the frequencies are grouped, it could certainly be busy around Mudgee or Inverell or Coonamble for example with at least 3 potential frequencies for rebroadcast - but that just lets people know that there's ACFT about, doesn't allow for mutually arranged separation if they're on different freqencies or overflying... as you said, doesn't cover all contingencies, and still need to look out the window, jet/turboprop or bugsmasher.....

There's no requirement to carry a transponder outside A, C or E airspace (base 8500 at present) and no requirement to have a radio OCTA below 5000 or in CTAFs. Thus OCTA TCAS doesn't provide full advice then from below 8500 and radios don't provide full advice from 5000 down..... this has been the situation for some time now. I won't even mention ACFT without electrical systems! Except (perhaps) for those who fly all the time in only classes A & C, looking out the window is part of your job. Does it actually do much good at higher speeds and descending/climbing through other's level - who really knows?

Just an aside, and correct me if I'm wrong, from what I understand NAS will extend class E to lower levels and would require TXP carriage - wouldn't that potentially be safer and cost non-TXP ACFT owners some dough? Not really a welcome cost (either to install the TXP or for loss of airspace) to a significant number of private fliers.....

Niles, I'm not convinced that NAS has much to offer the private or commercial pilot over the current system - I don't see it as really any safer nor do I understand (if anyone does) where the cost-cuts are coming from.

I'm not sure if the first aiders want to run the whole health system or if the superspecialised surgeons want the first aiders to do everything to operating theatre standards. There's space for both and that's the balance we need to achieve.

As for preventing two aircraft from occupying the same airspace simultaneously, we have a combination of defenses (radio broadcast alerting, ATC alerting, TCAS if we have it, flying more slowly in dense traffic areas, looking out the window, and the big sky itself)- all have differing importance depending on the phase of flight we're in and local density of traffic and none of which are infallible. Does anyone "scientifically" know the relative importance of any/all of these in preventing en-route tangles? I understand such variables are modelled to some extent when designing airspace.

In agreement with Manwell - when it comes down to it, I would still guesstimate that outside immediate aerodrome areas, in a large country with low density traffic, the sheer statistical improbability of two objects travelling on semi-random paths occupying the same lat/long/altitude at the same time has saved more of us OCTA than un/alerted see/avoid, radio and ATC alerts combined........and yes, I do look out the window and listen to the VHF!!

Fly safely:ok:

NOtimTAMs

[twodogsflying]

NOtimTAMs

What you are talking about is "airmanship", unfortunately, NAS will legislate the most important aspect out of existance and make us all use "See and Avoid" is the primary safety mitigator.

The NAS will remove the area frequencies from charts so all aircraft in "G" will have no idea what frequency they need to broardcast on when enroute. Mike Smith has publicly stated that their is no need and if you need to broardcast because of local traffic requirements, just use any frequency the local operators decide so no one else has to hear you. (last NT RAPAC meeting).

Unfortunately, NAS has not been debated properly, "the devil is in the detail" and we are finding out mostly by accident, what the limitations are. That is why I am opposed to it and why the argument of "It works in the US, so it will work here" does not hold any water, and all because for a so called benefit to GA and we can all become instructors and teach the masses how to fly. So far this is the only argument tabled in parliment for this airspace system, the Willoughby Report tabled in May.

[DickyBaby]

Manwell, it's not de rigour for traffic to be passed TO VFR but certainly on KNOWN VFR. Thus we have a responsibility where we can see VFR traffic (within radar coverage) or we've been providing services to VFRs and hence know about them.

In response to what we can see, the reality is that the coastal ccorridor coverage is pretty good but thins dramatically the further west you go until by Mudgee low level is invisible. Doesn't stop you getting a service but we can't see those pesky VFRs. As has been mentioned in several other threads a reply light on your transponder doesn't necessarily mean a corresponding return on our screens. We do the best we can with what we have.

Frequency management is much more problematic. Where we combine positions the SOP is to rebroadcast all transmissions on all frequencies that are being serviced by the one ATC. There are excellent reasons for this but the real decider is that we don't have as much over-transmission. So whilst each frequency gets busier, more info gets through. When positions are decombined then there's a lot of coordination going on with the operators of adjacent airspace. Thus if you're landing DU from the north, inbound IFR traffic from the south will be given directed traffic on you by the southern operators and thus have warning prior to transfer to CTAF. All "good" VFR operators will be monitoring the appropriate Area VHF and thus note your arrival.

When ATC says "Standby" generally this is to allow them to check with other ATCs or seeks more detailed info sources for you. It's not just to finish the story about the fishing last Thursday (although it might be).

The system isn't foolproof - and as you know we get a better and better class of fool each time we change something. We pass on what information we have, we alert VFRs that are doing something that could put the flight in jeopardy - even when they're not paying for a service. Anybody who operates in around the Hunter Valley knows how many times we have to warn VFRs that they've penetrated R532 whilst the AJs are happily lobbing mortar shells at them, thinking "Wow, they've got some real moving targets in this exercise!"

A good controller is sometimes a lazy controller. That is, interfering with traffic to the smallest amount possible that yields everyone arriving in one piece. If you have just one teeny little mid-air you get tied up with barristers for years and years. Keep 'em apart and you get to go home and think about almost anything except work.:ok:

[Icarus2001]

Good posts Dicky Baby.

All "good" VFR operators will be monitoring the appropriate Area VHF and thus note your arrival.

So when the frequencies are removed from the charts "for clarity" :rolleyes: How will the pilot know which frequency to monitor?

What frequency will a pilot give a Mayday or Pan call on? If it happens to be 126.7 Mhz will another pilot who hears this call be able to relay it to ATS if they do not know the correct frequency?

Using 121.5 mhz is hit and miss and also unrecorded so ATS and SAR agencies will not have replay capability.

[NOtimTAMs]

**WARNING - longwinded, may cause eyes to glaze over and inhibit scan **

To go back to the start of the post re: limitations of "see & avoid"

For those who fly in A & C only - not really an issue until someone with their transponder and radio off wander into their tracks outside primary radar cover;

For those who fly in D,G & E -

a. for radio broadcasts to be effective you need parties with operating radios listening on the same frequency delivering information on ACTUAL position and intentions - I think that all three requirements for this to be a consistently helpful defense are frequently not met;

b. for ATC broadcasts to be effective - ditto plus requirement to be radar visible and/or known traffic;

c. for TCAS - need a TCAS unit in your ACFT and operating transponders in the other ACFT - not mandatory outside class E (below 8500 at this stage) or ACFT without electrical systems, thus frequently not effective - what do the RPT guys do from 8500' (transponder mandatory in E) down to 5000' (radio mandatory in MBZ)? Cross their fingers, trust TCAS, slow down to look out the window, speed descent to minimise exposure or know that the big sky will protect them?;

d. alerted see & avoid - how many times have you been given info on traffic at 2 miles +/- 1000' at x o'clock and still not been able to see them? If you are on frequency though, at least you can arrange some mutual agreement on altitudinal separation....;

e. unalerted see and avoid - en route, this is virtually the same as big sky and occurs when the other defenses above are not present (which is frequently);

f. see and avoid approaching the circuit area (where most midairs occur) - at least we do slow down, look in the areas most likely to yield traffic as well as perform a general scan for traffic and we are hypervigilant - a state that we can maintain for the short period of time of joining circuit and landing, but not for the long periods of en-route. See and avoid is more likely to be successful in this environment but is not infallible. Only positive control down to ground level can improve on this, but is not affordable/practical outside major centres

g. Big sky - the statistical improbability that two ACFT will occupy precisely the same volume of airspace at precisely the same time protects us a lot more often than we think

My point is not that airmanship will save us, but that:
1. there are already frequent large gaps in the defenses available to us for prevention of en-route midairs,
2. that we do not really know or have quantified the relative or additive contributions that each of these defenses actually make;
3. that see and avoid (alerted or not) is very fallible as BASI indicates, and especially en-route;
3. that despite these current real gaps we don't have a tradition of en-route collisions;
4. we don't really know what effect that things such as withdrawing common radio communications outside controlled space will have - we just have opinions, which are like fundamental orifices... but I certainly agree with Icarus that the issue of emergency comms has not been adequately addressed

To interpret US vs Aust statistics on mid-airs we really need to consider en-route rates (not absolute numbers) only and factors such as traffic density. (I don't know about you, but I find the ATSB site frustrating to get any meaningful statistical information on this or many other topics.....:ugh: ).

Sentiment and the way I've been trained (often based on instructor's/check pilots habits and training, not always based on logic! ;) ) lean me to supporting the status quo rather than NAS but I'm open minded enough to to consider alternatives, and that NAS may even *possibly* be safety neutral relative to the current airspace in view of the above remarks.....but by God, the silence from the ARG is deafening :zzz:

Fly safely:ok:

NOtimTAMs

[WhatWasThat]

NoTimtams,
A couple of points for consideration, from the ATC side of the mike.

Re ATC alerted see and avoid - this seems to me to not be see and avoid at all, but more often pilot arranged procedural separation, I can count on one hand the number of times I have passed traffic to two IFRs and they have continued on their merry way without speaking to each other to arrange something. This makes me question the pilots faith in "see and avoid". Surely if the pilots were confident that they could sight and manoevre to avoid conflicting traffic, they would not be talking to each other at all.

Re Big Sky - whilst the sky is big the number of frequently travelled aerodromes is considerably smaller, this means that the probability of two aircraft welding cannot be assessed based on the total volume of australian airspace. Aircraft don't travel on random paths, they alter altitude and speed on a fixed trajectory between point A and B, this makes it much more likely that someone going B to A will hit you. The volume of Sky within which all the planes routinely operate would be a very small fraction of the total volume of Australian airspace, it only gets smaller as improved Nav performance means aircraft are closer to the nominal track between A and B. Even if the air route system were removed and free flight became the norm, the sky would still not be as big as it seems, as aircraft would still be contained in "corridors" between aerodrome pairs.

putting aside reciprocal tracks, I am still amazed at how often aircraft on crossing tracks in the GAFA or ocean arrive at the crossing point at the same time.Even with all that sky out there, we still have to move them more often than you might think. Admittedly the closest measurement I can make is to the minute, and there is still plenty of room within that tolerance for a miss - but its close enough for me.

[NOtimTAMs]

Like that handle - "WhatWasThat"

If you read my posts, you'll see we agree on the unreliability of see and avoid in all but the most structured environments.

We also agree that ACFT tracks are semi-random, as I have said above in previous postings, and as you say. They are "micro-modified" by things such as compass, DG, pilot and altimeter accuracy which give significant random variation to the actual 3-D path followed through the sky. In addition, those using coupled TSO'ed GPS's usually have a track offset to avoid oncoming..... Even with the "corridors" you suggest, there is a significant scope for random variation.

The places (especially outside C towers) which are frequently travelled by IFR ACFT are also more frequently travelled by VFR ACFT. Some of these places are CTAF's, some are MBZ's. There are plenty of spots where climb/descent/en-route IFR ACFT mix it with VFR ACFT and other IFR ACFT where they will not necessarily be on the same frequency (or otherwise be incapable of hearing each other), may not be visible on ATC radar, may not have TCAS/TXP's. For example, think Temora on a museum flying weekend with arrival/departures of jets/turbine/light GA/ultralights. Why then is there not a history of en-route midairs (or even climb/descent midairs) if such situations are common and we agree that see and avoid is so fallible????

How far is a minute ahead? Depends on the closing speeds - head on at 200KTS (i.e. 2 Skyhawks!) its 6 km, for 400 KTS its 12 km - that's a lot, really. If overtaking, can be very close indeed. Exactly what *distances* (not time) are you able to discriminate?

Bear in mind that sometimes one reason IFR pilots talk to each other when given the opportunity is not for pure operational reasons, but because John Laws or the country music on the ADF is boring them!! ;)

Safe flying :ok:

NOtimTAMs

[DickyBaby]

Icarus2001

It's actually worse than you might think. Pilots and ATCs are both lamenting the removal of frequencies from charts. This simple aide memoire helps us just as much as the weekend pilot. Nothing better than looking up at the chart over your head to confirm that the correct frequency for Oodnagallarby West is 128.55 (or whatever).

Despite what some people seem to think, most ATCs believe that they're there for a reason - something to do with enabling safe, orderly and expeditious flow of traffic (sorry strike expeditious, it's now cost-effective since affordable safety). Unfortunately the way of the industry at the moment is a push for provision of less services rather than more as it appears we can't afford the level of service we now have. Hence positions combined more often, more frequency congestion, less ability to deal with routine requests - we don't even give QNH anymore although I have heard some "overservicing" occuring.

I'm pretty proud of the Australian industry. We have a record not matched elsewhere and it's not all down to big sky. The vast bulk of our traffic is on the eastern seaboard. As long as all of us keep pushing for the best we can do then we should survive.

OOPS
DELETE SOAPBOX
GOSUB "SIGNOFF"

SIGNOFF

Getting back to frequencies, we don't monitor CTAF or 121.5. Sorry. We have to rely on you guys to let us know so we start the SAR process. Get alll your mates to keep there eyes and ears open and hopefully we'll all get home in one piece.

[Captain Custard]

Tim Tam,

What jets go to Temora during the museum weekend, and is this a regular occurrence?

PS: You are a red herring merchant:

+ TSO'd GPSs do NOT have an inbuilt track offset, and if you are IFR, it is illegal to be off track unless you're operating in OCA. And operating a GPS off-track, while being a good idea, is a pain because at the next waypoint it tries to steer you back on track, requiring a continual re-fiddle. I can assure you, sunshine, I have seen more metal go over or under my window than is made into cars! In the old days, it used to be "over there, or over there", but not any more. And I'll bet you london to a brick that your average joe-blow VFR is now spending more time in the cockpit drooling over his GPS than looking out!

+ There are not plenty of places where aircraft mix it not on the same frequency. And the current CTAF requires all aircraft with a radio to use it: the NAS does not. Given the spruiking of Dick Smith on the matter, there will very rapidly be a plethora of red-necks not talking because they don't have to.

+ The overtaking scenario is a furph and the least dangerous: now that Dick got rid of quadrantal levels, aircraft can be almost head-on. Read the BASI report and all your questions on See and Avoid will be answered.

So, the landscape will very much change for the worse with NAS!

[NOtimTAMs]

Cap'n C - no need to get personal, "sunshine"...... :D

A Beechjet goes in and out of Temora, for instance -
I understand it carries the fellow behind the museum.......been there a couple of times with everything from the Beechjet and Chieftains to no-radio Drifters, Karatoos and Sapphires (you do know what a Karatoo and a Sapphire are, don't you? ;) ) there, with IFR arcraft coming down through a mid-level overcast to where the visual folk were flying. This is not a "new" situation promulgated by Dick Smith.

You're right about not all TSO'ed GPS's having offset, apologies. The GNS430/530 combos coupled to A/P I've flown seem to be just under 1NM to R of track en-route and a *much* lesser distance to R of track in TERM mode, automatically - beats wandering around on a scalloping VOR radial. It's not illegal to be "off track" outside controlled airspace (BTW OCA means Oceanic Control Area, not outside control area) and RNAV tolerances for those who inadvertently wander are +/- 2NM before notification is required). For VFR ACFT there is a recommendation re: track offset for use of GPS made in an old AIC that is now buried in the CASA or ASA site - really should be promulgated more widely and used for IFR as well, in my opinion.

Quote: "I'll bet you london to a brick that your average joe-blow VFR is now spending more time in the cockpit drooling over his GPS than looking out!" .... and has the midair rate increased??

Quote: "Dick got rid of quadrantal levels" .... and has the midair rate increased??

We'll have to disagree re: plenty of places where aircraft mix it not on the same frequency. You may or may not be aware how many ACFT actually are able to get airborne without a radio or whose hand-held plug-in has very limited range, not to mention those boundary crossing scenarios or the high speed jet route areas (have a look at the Area 40 NOTAMs tonight for a nice chunk of Australian airspace). Radios are not compulsory in CTAFs or below 5000'. Aircraft without TXP are not visible on TCAS.

The only point of my overtaking vs. passing scenario was to try to get some answer from ASA folks as to the actual discrimination in DISTANCE (not time) that they can discern - WhatWasThat referred to a "minute", but that can refer to wildly different volumes of airspace. As for dangerous situations, I would contend that the overtaking descent/climb would be the potentially most dangerous, as I understand that it
has been the cause of most midairs in the aerodrome vicinity and circuit.

I think that the radio calls, transponder and concentrated look out make a positive contribution to safety in the vicinity of busier aerodromes, and I'd like to think that they do en-route..... but am not convinced really how much contribution they actually make in the latter situation in the low density traffic environment outside the major centres of Australia. Sometimes we're a bit bit precious about things we'd like to believe we have control over.......

And yes, I read the BASI report when it first came out.

Safe flying :ok:

NOtimTAMs

[Captain Custard]

Tim,

Arhh the old beechjet trick. Thanks for that really representative "jet" operation, upon which to base an argument. I do not know what a Karatoo and a Sapphire are, nor do I care. People are free to fly whatever they like, as long as they don't get in my way, or at least tell me that they are there, because, by the time I pick them up visually, they're dead (aswill probably be me and my pax). Perhaps you could give us a rundown on the visibility from, and the manoeuvrability of, said bugsmashers.

My post said OCA, because that was what I meant to say. I would have thought that you would have known why your GPS is consistently off track, or don't you have a manual for it, like you're supposed to if you're IFR?

I am also aware that radio is not compulsory in CTAFs: using it, if you have it, IS!!! When are you going to get the message?? That is one of the major differences between now and NAS!

Big deal about the "recommendation" to track off track: where is it is plain view for all the new chum VFRs to read?

And ref your quotes of mine increasing the midair rate: the rate is increasing: they just haven't started yet. But they will. Then what are you going to do? Say "it's all in the statistics: bound to happen, fact of life, get over it"?

[Captain Custard]

Tim and others who love the USNAS,

And while I'm on my hobby horse about the lunacy of unalerted See and Avoid, one country, a while ago (before Dick messed around with airspace in the name of harmonisation), had a speed limitation below 5000ft of 210kt, just to make lookout easier. It WASN'T the yanks or the boffins at ICAO headquarters....

[NOtimTAMs]

Aaaaah, Cap'n C.........it can be so hard to cope with change sometimes.

Sounds like you haven't even been around the CTAFs for a while, bit of a difference from a steady diet of Class A, C and OCA, eh?

Why, just today I had to descend through non-radio non-transponder glider traffic to a CTAF where there were ultralights and light GA ACFT. I must just be lucky to be alive, because I'm sure that kind of descent to such a CTAF must be so very rare......:eek:

CC, if you are having to descend through noncontrolled airspace through those pesky little planes, I'd strongly recommend you know what you're looking for when a Karatoo calls airborne!! At least I know now a Beechjet isn't a jet ;) ;) ;)

For the record, I am neither pro or anti NAS, I just have an open mind. However, I would like to hear some *facts* as to the en-route collision rate, either by comparison between current systems of airspace management, or between airspace models which account for the traffic loads. Even some logical argument would be nice. This has not been forthcoming from proponents or opponents of NAS.

I am also merely pointing out that there are numerous areas within our own current system that are not "protected" for IFR ACFT and that it seems there is no significant en-route collision rate.

Statements to the effect that the sky is falling are neither facts nor logical argument.

Safe flying:ok:

NOtimTAMs

(BTW CC, you're welcome to use an NDB or a VOR (with aggregate error up to 5 degrees) over being .5NM to R of track - maybe that's what I should be doing, but whenever I cross check the GPS with the VOR & NDB, it all seems OK :D . INS must be nice to have.)

[DickyBaby]

Only a small point NOtimTAMs,

I would like to hear some *facts* as to the en-route collision rate, either by comparison between current systems of airspace management, or between airspace models which account for the traffic loads. Even some logical argument would be nice. This has not been forthcoming from proponents or opponents of NAS.
and;

Statements to the effect that the sky is falling are neither facts nor logical argument.
From where I sit it's impossible to get facts or cogent discussion happening because sooner or later the "facts" are disputed as simple twisting of statistics. Our mate Winstun springs immediately to mind (another thread) assuring us that the annual rate of 20 midairs per annum (his figure not mine) is somehow acceptable (apparently because 43200 die in car crashes). Must be a collateral damage mentality - I just don't get it. 1 midair is one too many. No matter how wrong I get it, I'm not the one that dies. If you stuff up you die, if I stuff up you still die. I try not to stuff up. I'm just looking out for the aviators that operate under the blind assumption that they have a reasonable chance of surviving to destination.

The point is that the nay-sayers on both sides of the fence are stifling any real discussion. Where logical argument is presented, it seems by and large it is ignored. Being provocative is what gets following posts...

[Niles Crane]

A statement about FACTS.

I too would like some facts about airspace. The facts are, if the airspace is in place, no safety case or justification is required, by default we accept the current situation.

If this is true, why are we changing the current airspace and why are we changing to another outdated system.

We cannot get current airpsace facts so we cannot compare the current system to any new system. Seems odd, but thats the way it is.

The USA is looking into changing their system, but nothing has been finalised. Europe on the other hand has already done theirs and started a plan that will take a number of years with the end product being aircraft based, ie Known and Unknown.

Known will be similar to controlled airspace and Unknown will be similar to "G minus".

ICAO is also currently working on new airpace and the alphabet system will be dropped and probalbly going with the European Known and Unknown system.

So if the Smiths and others force us to the AUS NAS, we will once again have a unique Australian system that is not compatable with any airspace in the world all for so called ease of use for VFR pilots.

[NOtimTAMs]

Dicky

For stats to be remotely comparable on this subject, as you intimate, they have to be based on RATES not absolute numbers and have to relate to similar airspace, or at least the airspace type (e.g. high traffic levels vs low traffic levels [needs to be further spec'd];radar vs non-radar; transponder vs. no transponder etc.) must be specified so that judgment can be made as to whether this is a valid comparison or not. I'm sure the raw data is there, I'm sure that there are resourced government departments to refine the data - but we're hearing.....nothing. Does anyone actually know the answer to a simple question like: "what is the en-route midair collision rate OCTA in the USA?" ".... Australia?"

All risks we take are based on a perception of what is "acceptable" risk or not. Some people choose not to fly at all, some people won't drive in the city, some folk won't go up ladders. The concept of what is acceptable risk is coloured heavily by emotion. Some people are able to take in the concepts of probability and statistical likelihood and can look at rates of unacceptable outcomes and choose whether they wish to participate in the activity (e.g. surgical complication rates for certain procedures, accident rate for motorcycles, etc.) most of the time they will compare the perceived likelihood of an adverse event happening in a particular activity with an activity they accept every day, such as driving a motor vehicle for example. If an activity is presented as being safer than the acceptible everyday activity, then they are more likely to engage in it. Often this assessment made by individuals will be tempered by whether they feel thay have some control over the event happening (e.g. if I'm a really good driver/pilot etc. it's less likely to happen to me....) or the *perceived* ghastliness of the adverse outcome.

Whilst I understand the emotion behind "1 midair is one too many", the corollary is that the completely safe thing to do is not to engage in the activity at all, or if near complete relative safety is required, to put so many safeguards in that the activity becomes prohibitive in terms of time and/or money to engage in. To hark back to some of my previous posts, are you saying that I shouldn't descend *at all* OCTA under the current airspace situation, where there are non-radio/non-TXP aircraft, because I might hit something, even though there's no evidence for this (BTW, that "evidence" is just based on my recall of the last 10 years)?

Niles

The latter approach to safety, to put so many safeguards in that the activity becomes prohibitive in terms of time and/or money, is what the JAA is doing. Going down the road of the JARS may eke a little further safety, but is the cost (and loss of trees in the paperwork!!!) worth the cost to the industry? And more importantly does a system as devised by the JAA and perhaps to be followed its euro-buddy ICAO really relate to the low density traffic and spread out geographic nature of OUR country? Putting traffic lights on every corner of the road may reduce the enroute motor vehicle collision rate, but is the cost worth it and is it the most appropriate measure to take?? Are there places where there are too many traffic lights? Is it the most approriate allocation of limited funds?

Whilst I see airspace "harmonisation" can help the international carriers, it actually does b*gger all for the bulk of us that will never get to fly internationally either for a living or for pleasure (BTW , this is not sour grapes - good luck to those that get there). If you must, develop "fully harmonised" international rules for the international folk who stay cocooned in A,B,C & OCA, and leave the lower levels enough wriggle room under the exemptions to work out the best ways to get around THEIR country. It might sound isolationist, but geographically, that's what we are.

Be interesting to see if the Kings actually will have any FACTS to back up the assertions they will have to make in favour of NAS, and if the opponents can come up with the same....

Safe flying:ok:

NOtimTAMs