NAS - Common Risk Management Framework

[Clive]

VOR

I too wish to thank you for your input to this debate.

In the 4 and a half years I have been frequenting this forum I have never come across a topic so professionally debated.

It gives me great pleasure to read your thoughts, beliefs, and well educated dissertation on risk and safety in our industry.

It warms my heart to find someone “on the same page” (as the Americans would say) as I, in relation to a shared concern for the maturing of the safety culture and processes within our industry.

I trust you are in a senior position in aviation safety management and hope your skills are being put to good use in our risk and threat rich environment.

Godspeed my friend.

[Dick Smith]

Wellconcerned, I’m very happy to donate to the Royal Flying Doctor Service separately to my offer in relation to VOR. You come up with an amount that you will put in, and I’ll put in the same.

[Dick Smith]

VOR on your post dated 20 June 2007, you made the following statement:

This in fact what Europe has done in implementing certain procedures from the United States recently. They conducted what is known as a reference study, using a number of operating environments in the United States that as closely as possible match the target operating environments in the Europe.

This gives you a twofold benefit. First, it provides a reasonable benchmark – and gives a value to the potential benefit that may accrue from implementing the change … The second benefit – and this is important for you as a change proponent - is that it extricates you from the role of change proponent AND risk arbiter [a conflict of interest]...

My suggestion is you look at the NAS document. You will see under Safety Analysis Methodology 3.1, that it is quite clear that NAS follows the reference system methodology.

Yes, I was one of the change proponents, but I certainly was not the risk arbiter.

It is extraordinary that Airservices has gone down the path of creating a most complex fault tree analysis to support reversing the Class E over D when Europe has implemented procedures from the United States by following the reference system methodology that was proposed in the Australian NAS document as approved by Cabinet. Let’s hope that Adrian Dumsa can get Airservices to follow the reference system model in future.

By the way, what were the procedures that Europe has implemented which come from the United States?

[SM4 Pirate]

You will see under Safety Analysis Methodology 3.1, that it is quite clear that NAS follows the reference system methodology.

What does that mean? Call it the USA model and therefore no safety assessment is required because they have enough safety? The question I then ask is it really the same system? Especially in transition?

[Dick Smith]

Can anyone advise on the TCAS in trial climb procedures used by airlines in the Oceanic airspace?

I understand this procedure relies on TCAS, outside of radar coverage and the TCAS is used as a risk mitagator in planning and managing this type of airspace.

Why is this trial accepted by the countries concerned? Does ICAO, have any objections?

[V.O.R]

Mr Smith,

We had intended to leave this thread - and will after this final post.

TCAS In-Trail [Climb] Procedures [ITP] were developed by the FAA in the mid 1990's for use in the transition airspace off the coasts of the United States - primarily the oceanic transition zones east of New York, and West of Oakland Centres.

ITP was meant to address problems where heavy long haul aircraft were climbing slowly, and could not reach a preferred level before leaving radar coverage [around 250Nm] - and so might be held down below another aircraft.

ITP was designed to allow two consenting aircraft to 'self separate' under quite strict conditions, allowing the following lower aircraft to climb through the level of the leading aircraft.

One of the requirements was that the following aircraft must positively identify the aircraft whose level it intended to climb through.

As you know, TCAS will show you level and position information on other aircraft in the vicinity - but not callsign - so procedures had to be developed whereby the following aircraft would ask the leading aircraft to turn its transponder off for a short period of time. If positive identification was made, and there was an appropriate distance between them [around 20NM] - AND if ATC agreed, the following aircraft could climd to a higher level.

We understand that only three US companies, including United Airlines, agreed to allow the procedure to be used in their company policies - only one airline [United] actually used the procedure more than a few times [we have not had time to check with colleagues here to confirm current application].

We understand that controllers in New York rejected the procedure as too labour intensive [and before you indict the controllers, you need to understand that the NY Oceanic Centre is one of the busiest en-route centres in the world, handling both North Atlantic entry/exit traffic - and the WATRS airspace]. Only Oakland contined to make the procedure available. We are not aware to TCAS ITP being applied anywhere else in the world.

TCAS ITP was not, and is not, intended to be used for regular separation functions, and as the recent NASA study [refer link below] shows, the minimum safe spacing between aircraft using the procedure is determined to be 15NM.

http://shemesh.larc.nasa.gov/people/...afety_perf.pdf


Note that one of the hurdles you would need to overcome in using TCAS as a separation tool, rather than a conflict resolution tool, is the fact that TCAS is designed to give warnings, and resolution advisories, if the spacing between the aircraft comes below preset minima. So, trying to fly 100 feet from another aircraft would generate resolution advisories in both cockpits, leaving substantial room for misunderstanding [refer the report of the Uberlingen accident].

Of course, you could move from Resolution Advisory to Traffic Advisory mode - but we suspect you would find a lot of resistance from pilots [that is not to say it can't be done - we understand it is done at your Sydney airport in parallel runway operations, under quite controlled conditions].

FAA, and, we believe, Australia, are trialing ITP using ADS-B. This should provide better opportunities for self separation, given the positive identity that unique code ADS-B provides.

We commend to you [and other readers] the study referred to above. It is a fine example of a proper safety study.

As a point of interest, and not to put too much emphasis on it, we recommend you read the first paragraph under section 4.4 on page 23. We are sure this will generate some responses.

[WELLCONCERNED]

OK. If no-one else will bite, I will!

I read the section in the report.

How come the FAA mandates 'see and avoid', but our ATSB says its not effective and pilots shouldn't rely on it?

BTW - good response on TCAS!

[putytat]

It would appear that Mr Smith just cannot leave TCAS alone. An election looming, Govt struggling in the polls; Here comes TCAS as a risk mitigator!!

You Honor, I again rest my case.

Another first for Aus!! First is not always the winner though.

SEE and AVOID is flawed! Ask any pilot who has obscured vision from the cockpit, particularly in marginal VMC. ATSB is correct.

[Chimbu chuckles]

Wellconcerned I post it here for you to read again.

A crew operating an aircraft, regardless of whether an operation is conducted under instrument flight rules or visual flight rules, should perform the function of see and avoid to prevent a collision.

This requirement is mandated in the USA National Airspace System under Chapter 14 of the Code of Federal Regulations, Part 91.113. A flight crew of an aircraft which is in a collision trajectory can successfully implement the see and avoid functionality if it can visually acquire the traffic in sufficient time to perform an avoidance maneuver.

There are several factors that affect the probability of visually acquiring a traffic aircraft by the own ship (or the own ship being visually acquired by the traffic). The geometry of the encounter is one of such factors.
Figure 21 in Section 4.6 depict possible geometries for which visual acquisition is not possible.

A visual acquisition program, Visual 3D, was used to determine the probability that an aircraft, which is in a collision course with a traffic aircraft, will see the traffic in sufficient time to avoid a collision [8,9].
The time required to avoid a collision after visually acquiring a target has been estimated to be on the order of 12 seconds [10]. The visual acquisition program uses the following parameters to estimate the
probability of seeing the traffic:

'See and avoid' might be a perfectly reasonable procedure for aircraft in trail in VMC but 12 seconds is about 7 seconds to long when anywhere close to head on...that is why ATSB suggests most strongly that see and avoid is not the panacea DS likes to portray.

This procedure was suggested for aircraft operating in trail...that is following along a precisely defined FMC track in the same direction at very close to the same speed...a maximum typical speed delta of Mach .04.

TCAS gives an accurate distance to target but the bearing information is not near as accurate...but when it is near impossible for the following aircraft to actually catch the preceeding aircraft it's bearing becomes irrelevant...anyway you know the bearing because they are on the same airway as you.

[WELLCONCERNED]

Sorry CC.

I read it totally the wrong way. Now I get it.

See and avoid has a chance of working, but only IF YOU CAN SEE the object to be AVOIDED.

Thanks for the correction.

[Scurvy.D.Dog]

Exactly
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.. which begs the question/s … how the hell do RPT IFR get 100% alerted see and avoid in non-surveillance airspace …. only two ways:-
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1. everyone is known via radio and receives DTI (directed traffic information); or
2. everyone is known via radio and receives an ‘Air Traffic Control Service’ (ICAO D or higher)
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Because:-
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- IFR RPT may not have mode S ‘in’ or TCAS to alert themselves,; and
- 100% of the threat traffic may not be transponding!
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Until TXPDRS (Mode C/S) are mandated, and made active at all times (as Brazil has shown us) whilst the aircraft is moving, and RPT have 'in', a third party and radio is unavoidable!
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Now don’t glaze over .. stay with me on this (one last time) …. IMHO, if one takes the process one step further:-
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In determining the level of alert/ATS service appropriate for a given parcel of airspace:-
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It should be as simple as determining CTA or OCTA
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CTA should be:-
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- ICAO D below FL150 where surveillance exists (as there is no discernable difference in the cost of providing D or E)
- ICAO C FL150 up to FL280 where surveillance exists (closing speeds during late climb/enroute cruise means ‘Alerted See and Avoid’ becomes impractical for IFR/VFR/VFR conflict pairs FL150 and above), ATC separation standards should be a must for IFR AND VFR at those speeds! VFR to operate at same altitudes as IFR i.e. FL160 rather than FL155 or FL165 .. as this provides no ‘500ft’ separation complications with larger aircraft .. ease of level assignment planning and wake turbulence considerations!
- ICAO A above FL280
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To Pilots, the service level (D, C or A) becomes transparent!
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OCTA should be:-
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- ICAO F (flight service DTI)
- IFR participate
- IFR receive DTI on IFR
- VFR monitor and (on request) flight following (where surveillance exist)
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where surveillance exists (say remote terminal areas and surrounds) give the picture to the FSO for the provision of DTI to IFR on IFR and ‘known’ VFR
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Two classes of ‘serviced’ airspace only!
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CTA where traffic volume and complexity warrants such as terminal areas (inverted wedding cake)
OCTA where ATS frequencies exists, and CTA is not established
DRA (designated remote area) where no ATS frequencies exist, ICAO G … nil services (pilot to pilot only) similar to TIBA
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One aspect of determining CTA or OCTA
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- Just one of the many factors considered will of course be frequency loading caused by DTI and pilot to pilot arranged ‘segregation’, weighed against the less saturated frequency of an ‘Air Traffic Control Service’ which unloads the frequency through ATS Separation Standards (no DTI babble)
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Pilots should only need to know:-
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CTA
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IFR
- comply with the clearance
- Below FL150 listen for DTI on VFR, then look for the VFR (alerted see and avoid with ATS segregation)
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VFR Operations FL145 and below
- Comply with issued clearances or proceed as notified once acknowledged by ATC
- Broadcast change of intentions, and receive an acknowledgement from ATC before executing the change in track or level
- Listen for DTI on IFR and VFR
- Look out for IFR and VFR
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VFR Operations FL150 up to FL280
-Comply with issued clearances
-Operate at whole (IFR) levels
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OCTA
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IFR
- Listen out and look for alerted IFR and VFR (receive positional DTI in surveillance areas, workload permitting)
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VFR
- Listen out for IFR and look for IFR and VFR (receive positional DTI in surveillance areas, workload permitting)
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Workload permitting must be stated given ATS (flight service) cannot limit traffic or unload the frequency with 'separation' OCTA
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ATS should only need to know:-
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CTA
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- IFR are ‘separated’ from IFR and SVFR
- IFR may be ‘separated’ from VFR (no traffic information required); or
- IFR may be ‘segregated’ from VFR (IFR receive DTI on the VFR in this case, and VFR receive Wake Turbulence cautions where required)
- VFR are ‘segregated’ from other VFR; or provided DTI on other VFR (workload permitting)
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ATC’s retain the discretion to apply:-
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- a ‘separation standard’; or
- issue DTI where ‘segregation’ can be reasonably assured
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i.e. a separation standard does not exist however through surveillance it can be determined that the proximity of two or more aircraft is not unsafe (defined as a larger margin than that which constitutes an Airprox)
ATC’s can use bigger margins (due workload) such as ‘standards’ to mitigate frequency and work loadings or smaller ‘segregation DTI’ as desired or required at any given time … it is transparent to pilots!
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Where a ‘separation standard’ does not exist, IFR pilots receive a Directed Traffic Information service for sighting purposes.
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Where a ‘separation standard’ does not exist, VFR pilots may receive a Directed Traffic Information service (workload permitting)
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As with the FAA reg’s, the ability or otherwise of an ATC to provide a service to VFR in respect of other VFR is not questionable after the fact (otherwise you will never have their agreement to provide services to VFR/VFR on a when able basis)
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OCTA
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ATS Flight Service
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- IFR receive DTI on IFR and ‘known’ VFR (workload permitting)
- ‘Known’ VFR receive DTI on IFR and ‘known’ VFR (workload permitting)
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General notes OCTA
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’known’ VFR are those ‘seen’ in surveillance areas
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VFR should only broadcast within 10minutes flight time of a CTAF (F)
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CTAF (F) is serviced ICAO F and may include surveillance DTI
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Add to the risk equation the simplicity in mapping and regulations (both ATS and Aircrew), it should create a risk reduction right there. Much of this would put a serious dent in some of the inherent risks of the current system, and when compared against ICAO E and G … well?
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How it would go against C or B below FL150 is the bit I would be most interested in learning about! (other ATC’s and metal drivers around the major capitals please comment)
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Cost effective and safe with reasonable access is the name of the game is it not?
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… FARKK I hear you all say ... it really is simple in practice when compared to multiple classes of CTA and OCTA (as we have now) and having to understand what you will/might get as far as anti-collision services!! .. that’s what is doin’ everyone’s head in!!
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Why do I think the the above is simple (for you lot) and works safely and effectively (for us and you lot)? …. I use Surveillance D everyday, and (although not current) I am a bug smasher driver too!
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It is about as close too US NAS practices, and a simple I can come up with that fits CTA/OCTA contemporary expectations of service safety and efficiency!
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... as for where (geographically) CTA and OCTA should exist .... over to ewe's

[WELLCONCERNED]

Yes, Mr Dog, but...

...aren't you going in the same circles as everyone else when you suggest where the various airspace divisions should go? Dick says put Class X here and Class Y there. You say put Class X somewhere else and Class Y somewhere else, and add Class Z. Others suggest putting the boundaries in other places.

Wasn't VOR suggesting that before you even think about what airspace class to use, and where to put it, you should do a proper risk analysis? And wasn't that the point of this thread? To get us to agree to the risk management process before we start assigning labels and locations.

Seems like we're going in the same circles we've been round for the last 15-20 years.

[Scurvy.D.Dog]

... no ... quite the opposite!
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... determine where CTA is required (as per VOR explained process)
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... then apply a common set of CTA rules as above
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... where CTA is not required .. OCTA as above
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All I am suggesting is simplifing the variables in the application/s and recognising the safety/risk benefit to both CTA and OCTA of simple common rules!
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.. in simple terms, ask yourselves:-
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- do I really understand what I can expect in classes G, E, D, C, B and A airspaces?
- do I clearly know where those airspaces are and end or change?
- do I really understand what I can expect (and how do I know) within surveillance coverage in any given class of airspace?
- do I really know what to look for and when in any given class of airspace
- do I think frequency management at the moment give me the best chance of knowing where actual threat traffic might be?
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.. now if you know and fully understand that maze of variables in familiar and not so familiar airspace areas, then I would suggest you are in the minority!
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.. surely by comparison, pilots knowing only 2 sets of rules and expectations i.e. CTA and OCTA removes a deal of complexity (mapping and rules) and therefore reducing opportunities for confusion?!
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The suggested simplification/s above (in a vertical sense SFC- FL150- FL280) are not to be confused with allocation geopraphically as determined by the common risk management processes
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.. at some point, reducing complexity must be considered in the overall picture ..as I have tried to explain (perhaps not very well)

[werbil]

Scurvy.D.Dog - Your suggestions sound awfully like the procedures that were replaced back in the early 1990's - except for DRA's.From a pilot's perspective I understand the difference between the different classes of alphabet airspace - if you don't understand them you shouldn't be flying in that class of airspace.

The CTAF(R) system works extremely well in the YBHM area (especially since the establishment of a discrete frequency last year) where there may be a couple of dozen fixed wing (including seaplanes) and helicopters flying around below 2000 AMSL (mostly VFR) to numerous landing areas. It is often easier to develop a complete situational awareness of other traffic when the airspace is "G" than when the tower is open and the airspace is class "D". Mind you we do reply when in conflict in "G" to facilitate separation.

I personally believe that "E" is a great airspace classification - I just think that it is poorly implemented in Australia. Before I get flamed - I believe it would work well on a two frequency system - a frequency for IFR to talk to ATC and a working frequency that all aircraft broadcast their intentions on, however this would require IFR aircraft to have two VHF comms. This "multicom frequency" for want of a better word would need to be separated in level bands so that the high density of low altitude VFR aircraft do not congest enroute aircraft flying at higher levels (say one frequency B050, another frequency A050-A100 and a third frequency above FL100). And before you say a pilot can't do it - way back in the 80's outside VHF FIS coverage IFR flights had to report and receive traffic information on HF and broadcast on VHF. OK the workload will be higher in VMC, but when you're in IMC you won't need to worry about listening for VFR aircraft as there shouldn't be any there anyway. And yes - this would need scientific analysis to determine if and where it is appropriate.

I have no argument with change - but as VOR suggests only implement change after a process to determine that the benefits outweigh the risks and negatives has been undertaken and not just to implement change for change's sake or that's because how some other country does it.

Most importantly ALL pilots MUST understand and follow the rules and procedures for whatever class of airspace they are in. BFR's are there to ensure a pilot is procifient, and as far as I am concerned proficiency includes radio and airspace procedures as well as the basic stick and rudder skills.

W.

BTW One thing that doesn't make sense to me - when the YBHM tower is closed I only have to fly clear of cloud. When YBHM tower is open I am required to be 1500m horizontally or 1000ft vertically clear of cloud unless I obtain a special VFR clearance when ATC has to close the zone to ALL other aircraft. Somebody please explain the logic in that (and yes high capacity RPT DOES operate when the tower is closed).

[Scurvy.D.Dog]

Werbil some interesting issues raised .. certainly worthy of a considered response.
I have used separate quotes to respond to. It is not intended to be rude, rather ensure the context of my reply is properly understood!

- Your suggestions sound awfully like the procedures that were replaced back in the early 1990's - except for DRA's.

.. don’t ya’ remember designated remote areas .. you mustn’t have been around that long .. yes it is similar OCTA, with the benefit of utilising today’s technology to enhance it. In any event, compare it to Aus G at the moment (if you can that is)!
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.. the difference is reducing the number of frequencies for IFR and VFR giving them a better ability to receive the fullest traffic picture possible … no missing calls on the other frequency close into CTAF’s etc! … even if the OCTA stuff was identical to the F of the past (which it is not) … are you arguing that it is less effective than the current?

From a pilot's perspective I understand the difference between the different classes of alphabet airspace

… with respect, I think most folks understand the ‘differences’ in classes of airspace, that is not the point. The point is the practical application (what it does NOT deliver as far as SA to both ATS and Aircrew), complexity and therefore compliance (knowing the what to expect and being actively aware of what that means as far as their SA)!

- if you don't understand them you shouldn't be flying in that class of airspace.

… no argument there, again it is not the point. The point is the variable complexity provides additional opportunities for error or un-alerted Airprox!

The CTAF(R) system works extremely well in the YBHM area (especially since the establishment of a discrete frequency last year) where there may be a couple of dozen fixed wing (including seaplanes) and helicopters flying around below 2000 AMSL (mostly VFR) to numerous landing areas.

great to hear! … that area of local activity on a common CTAF freq is basically an AFIZ (for the dinosaurs) .. whilst you are belting around below 2000ft broadcasting when you feel it appropriate … how much of that traffic does the IFR RPT Jet/Turbo-prop slowing up from 250KTS on the drop really know? If the F (FSO) function was being provided on the same frequency, the IFR would not have to make separate broadcasts on a different freq, you and the VFR colleagues would hear those transmissions, and the IFR and FSO would hear yours …. ALL OF THEM! …. Granted, the geographical areas serviced by any one given OCTA frequency would have to be assessed carefully for loadings! …. BUT … it delivers the nearest you can get to 100% alerted traffic for IFR and VFR … and most particularly IFR RPT! .. that is what the discussion is about is it not?

It is often easier to develop a complete situational awareness of other traffic when the airspace is "G" than when the tower is open and the airspace is class "D".

… Well, isn’t that what CTA is for? a third party who is trained and rated to provide a standard of services that will only alert you when there is a reason to i.e. ‘relevant’ threat traffic when it is necessary .. as I said earlier, if a separation ‘standard’ exists between you and other IFR or VFR, ATC won’t load the frequency with traffic information on aircraft that are no threat to you.
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OCTA (CTAF) means you MUST hear, and understand traffic calls and know how that flight will interact with yours ….. not to mention … how many you do not hear or do not transmit that may be lurking or closing fast … most of us have had that surprise at some point!
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TWR D … OCTA CTAF (R) ….. ??? this is ‘part’ of the assessment process to determine if a parcel of airspace is utilised to a level that becomes unmanageable from a frequency use and loading point of view! In the context of CTA and OCTA the difference in this regard is clear:-
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- CTA = third party traffic management
- OCTA = pilot arranged ‘segregation’ (with or without third party DTI)
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.. how much is too much do ya’s reckon? … how much frequency activity before the average GA jockey, let alone RPT Jet/turbo jockeys are gunna absorb before SA is lost or impaired?? … mores the point, at what level of access is it reasonable to expect pilots of motorised hang-gliders, to Navajo’s to B737 or A320’s to rely on the others ability to be a competent self trained ‘self segregator’?

Mind you we do reply when in conflict in "G" to facilitate separation.

..glad to hear that you speak-up!
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.. on the subject … it might be semantics, but in the context of discussion of airspace, self arranged ‘anything’ is ‘segregation’ not ‘separation’!
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‘Separation’ infers a separation standard as described by ICAO (parent docs such as 4444), the MoS (CASR Manual of Standards), and the MATS (Manual of Air Traffic Services), as applied by ATC (not FS or Aircrew). Apart from 1000ft Vertical (which is widely known), other self arranged lateral, longitudinal (distance or time based) segregations being referred to as ‘separation’ is potentially misleading. I only raise this as IMHO it is creating erroneous understanding of expectations OCTA.

I personally believe that "E" is a great airspace classification

.. do you operate VFR or IFR? .. do you have TCAS .. do you pay insurance and fly paying passengers? .. not being smart, but think of others operating in the airspace!

- I just think that it is poorly implemented in Australia.

… no argument there!

Before I get flamed - I believe it would work well on a two frequency system - a frequency for IFR to talk to ATC and a working frequency that all aircraft broadcast their intentions on, however this would require IFR aircraft to have two VHF comms.

… this is what you in effect have now … IFR cannot listen on two (concurrently) reasonably busy frequencies effectively when monitoring both means often the two frequencies tandem transmissions are over the top of each other in the headset! … again, I stand to be corrected on this, but one of the most labour intensive items on an IFR flight deck seems to be selecting and de-selecting frequencies and hanging off the volume control! … I cannot see how that is better from an SA point of view when compared to a single frequency in a given geographical area OCTA (that may include 2 or 3 aerodromes in a vicinity Flinders Island or YSDU/NRM examples I am familiar with).

This "multicom frequency" for want of a better word would need to be separated in level bands so that the high density of low altitude VFR aircraft do not congest enroute aircraft flying at higher levels (say one frequency B050, another frequency A050-A100 and a third frequency above FL100).

OK, so:-
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- VFR operating wholly B050 will need to know and juggles between the CTAF freq’s appropriate for the flight, and the multicom B050
= 2 frequencies minimum (3 if they are interested in high speed IFR with ATS)
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- IFR operating wholly B050 (unlikely in some areas given LSALT’s) will need to juggle ATS area, CTAF/s appropriate for the flight, and the multicom
= 3 frequencies minimum
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- IFR operating SFC to B100
= 4 Frequencies minimum
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- IFR (pressurised) operating to higher levels
= 5 Frequencies minimum (if the base of CTA is FL125 or higher)
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I am sure the SAAB/DHC8/BRAS/Embraer/Boeing and Airbus drivers climbing and descending through that 5 or 6 times a day will be very happy with that, particularly if (as I assume) they are expected to broadcast on each frequency (some more than once i.e. ATS) from the SFC to base of CTA or CTA to SFC for arrivals …. Reasonable from as SA point of view? … are VFR expected to broadcast on these multicom frequencies??

And before you say a pilot can't do it - way back in the 80's outside VHF FIS coverage IFR flights had to report and receive traffic information on HF and broadcast on VHF.

.. never said a pilot can’t do it! The example you cite is 2 frequencies, and only because of the absence of an ATS VHF in that area otherwise in the same example 1 frequency!

OK the workload will be higher in VMC, but when you're in IMC you won't need to worry about listening for VFR aircraft as there shouldn't be any there anyway.

… errm how is that different in the scenario I put??

And yes - this would need scientific analysis to determine if and where it is appropriate.

AMEN

I have no argument with change - but as VOR suggests only implement change after a process to determine that the benefits outweigh the risks and negatives has been undertaken and not just to implement change for change's sake or that's because how some other country does it.

again AMEN .. I am not suggesting anything other … there might be another contributor who sees it the way you describe it (based on past performances) … not this little black duck though .. scurrilous to suggest it really!

Most importantly ALL pilots MUST understand and follow the rules and procedures for whatever class of airspace they are in.

.. we are in lock step here fella

BFR's are there to ensure a pilot is procifient, and as far as I am concerned proficiency includes radio and airspace procedures as well as the basic stick and rudder skills.

… come and spend some time plugged in listening to the results of the last ten+ years of GA and in particular VFR disengagement with ATS … BFR’s and other standards and mechanisms for proficiency in radio telephony are not working terribly well, particularly where that pilot instruction is mostly outside ATS areas!

BTW One thing that doesn't make sense to me - when the YBHM tower is closed I only have to fly clear of cloud. When YBHM tower is open I am required to be 1500m horizontally or 1000ft vertically clear of cloud

.. because when you are receiving an ATS service, the rules supporting that are designed to give you, and other VFR and IFR a fighting chance of seing you, particularly in an IFR/VFR conflict situation, where ATC are contemplating relaxing vertical separation by assigning visual separation to a pilot! .. just to name one!

unless I obtain a special VFR clearance when ATC has to close the zone to ALL other aircraft.

ATC do not close the zone for SVFR ..sport!
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.. SVFR can be due cloud OR visibility!
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.. Due Cloud
… if you are operating VFR .. say …not above A025 and the cloud base is A035 on QNH (although we all know the cloud is referenced AGL …) there’s your 1000ft rule right there!
.. ATC can descend an IFR to 1000ft above you cleared altitude i.e. A035 (not below the steps etc) and have a fighting chance of:- 1. getting the IFR in sight and applying visual separation from the tower 2. getting the IFR into visual conditions for further descent 3. asking the VFR to sight and then maintain visual separation from the IFR 4. have the IFR sight and then maintain visual separation from the VFR
If you were permitted to operate closer than 1000ft vertically from cloud in CTA, …. who gets fecked over? … IFR, ATC and VFR (you) because you will not get a clearance that will leave an arriving IFR in cloud over the top … sorry n’ all!
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Due visibility
.. if you are operating VFR ..say ..not above A010 and there is no discernable or uniform cloud base, the lowest an IFR can be cleared is A020 (not below the DME steps etc) .. why?
.. because 1. ATC may not/cannot see you (to apply visual separation) 2. the IFR may not be able to see you (from A020) and therefore cannot be assured of continuing to see you (visibility remember) on descent (pilot assigned visual separation) 3. If the IFR requires an instrument approach (due the visibility) then in the absence of visual separation, a procedural standard is required (remember neither you or the IFR can see each other) 4. once an IFR aircraft is cleared for an instrument approach (whether VOR, NDB, GNSS, ILS), the navigation tolerances are considered all the way to the threshold and the missed approach path . Unless you have visual reference to a geographical fix that is clear of the procedural tolerances of the IFR approach … you loose! …as quite frankly VFR in less than VMC are treated as IFR for that reason. Believe me, in SVFR (due visibility) conditions the average VFR pilot is often not sure of their actual position or misidentify where they are … TSAD has shown us that!
.
Now if you are SVFR and you lodge a plan that tells us you can use a VOR, or DME .. that’s a different story!

Somebody please explain the logic in that

.. hope that helped!

(and yes high capacity RPT DOES operate when the tower is closed).

.. with you lurkin around below the cloudbase or in marginal visibility ol’ cock … hope your TXPDR is on and accurate and the big guys are nice and slow early! ….IMHO, It should be the same (1000ft and 1.5klm) OCTA .. in fact it is more important for the reasons explained above .... perhaps another example of difference for no apparent reason ....
.
Nite all

[werbil]

Scurvy.D.Dog,

Some very interesting responses, and definitely worthy of a reply to explain further to allow you to understand the why of my suggestions. Fundamentally, I am sure we are going to agree to disagree on a number of issues - I am assuming we operate in two very different sectors of aviation. I fly float planes (including turboprops) in single pilot VFR SE charter (yes I carry pax, transponder and carry carriers liability insurance). I am assuming that you fly either RPT or corporate pure jet because of your responses (or possibly ATC - but if so you should have advised this in your response).

When full reporting for VFR ceased in the early 90's it was a culture change - we had to learn to listen for calls from other aircraft. And then when NAS was introduced VFR aircraft were expected to remain silent on center frequencies in "E" & "G" unless in conflict with an IFR aircraft. The fundamental problem I have with this system (in both "E" & "G") is that it requires the VFR pilot (who is probably less experienced) to not only have the correct frequency selected, but also have the volume set appropriately and have enough SA to understand if the aircraft is in conflict. If this fails, with a 250 knot closing speed (theoretically could be 500 knots B100) and 5000m clearance from cloud both aircraft could be "sharing" the same airspace in under 12 seconds from the first possible opportunity for visual acquisition. And remember transponders are only required to be fitted in "A" and "C" airspace, above 10000ft (except gliders) and in "E" airspace if the aircraft has an engine driven electrical system, and radios are not required in G B050 (except CTAF R's) or for gliders. No radio, no transponder at 1000' - seriously is this a problem over a station strip in the middle of the outback - no, would this be a problem over YBBN - oath it would be.

Yes a third party directed traffic service does remove some of the risks, but it still requires accurate position information from ALL pilots to work. I don't believe that anyone involved in aviation would for a second seriously suggest that all of Australia should be covered by radar "B" or "C" airspace - this would be simple for pilots - one procedure, and give the lowest risk for breakdown in separation - but imagine the cost.

My recollection is that alphabet airspace was introduced to harmonize Australian procedures with other countries (make it simpler for overseas pilots). Alphabet airspaces does not include a system the matched the old OCTA system -(directed traffic to and about all aircraft including VFR).

OK, so now I am getting to the crunch. Traffic, and location being equal, the earlier the letter the lower the risk of collision in the airspace should be. I think that the old OCTA system is closest to either "D" airspace (except IFR receives traffic information rather than a separation service) or "F" airspace (except all aircraft receive a traffic information service). So the risk of collision between a VFR and any other aircraft is now probably greater in both "E" and "G" airspace, the risk of collision between two IFR aircraft is now probably higher in "G" airspace and lower in "E" airspace. Two IFR aircraft means that both aircraft could be in cloud removing any possibility of a collision being avoided by "see and avoid". In other words I am NOT convinced that the old OCTA system was safer than class E airspace for IFR aircraft.

Secondly, flexibility in airspace procedures is essential because the usage of airspace is different. Where there is a large number of RPT, airspace procedures should be optimized for IFR - "C" or "B" are logical and obvious. Where there is no reasonable possibility of IFR (ie no approach procedures) airspace procedures should be optimized for VFR. The difficult ones are places which has only a few jet or IFR movements a day (like YBPN which has little other traffic or YBHM which has a large amount of VFR traffic).

The reason I suggested a multicom system is to allow VFR aircraft to broadcast their position and intention to other aircraft on a routine basis. Actually I would prefer the old system where VFR aircraft were encouraged to routinely broadcast on the center frequency, but now days this is very much discouraged (according to the AIP) except when responding to a conflicting IFR aircraft. Yes level banding has its limitations, but it will reduce the radio clutter from distant, high altitude traffic, and every aircraft has an altimeter that tells the pilot when to change frequencies. The intention of my suggestion is that CTAF calls would be made on the B050 multicom frequency (except where a discrete CTAF frequency is established) to reduce the number of frequencies that have to be handled. Remember the days of frequency after frequency being retransmitted by ATC - if you weren't getting directed traffic the bloke at the other end of the state could be loader and clearer than the other guy only 20nm away.

As for the RPT drivers - establish class C or D wherever you like - just don't ask me (or my pax) to pay for it in areas where it cannot be justified. I will use it if it is there to access the airspace, but I am happy in G. I would be much happier when in either E or G to be able make regular broadcasts that all other pilots can hear when en route though.

don’t ya’ remember designated remote areas .. you mustn’t have been around that long .. yes it is similar OCTA, with the benefit of utilizing today’s technology to enhance it. In any event, compare it to Aus G at the moment (if you can that is)!

DRA's are still in CAO 20.11 - they're just less relevant as all aircraft have to carry an ELT now days anyway. I don't remember the radio procedures being any different - my hazy memory is that you had to broadcast on the area VHF frequency and if operating full reporting report on HF when outside VHF range or lodge a SARTIME and carry an ELT if you didn't have HF - does this sound right?

that area of local activity on a common CTAF freq is basically an AFIZ (for the dinosaurs) .. whilst you are belting around below 2000ft broadcasting when you feel it appropriate … how much of that traffic does the IFR RPT Jet/Turbo-prop slowing up from 250KTS on the drop really know? If the F (FSO) function was being provided on the same frequency, the IFR would not have to make separate broadcasts on a different freq, you and the VFR colleagues would hear those transmissions, and the IFR and FSO would hear yours …. ALL OF THEM! …. Granted, the geographical areas serviced by any one given OCTA frequency would have to be assessed carefully for loadings! …. BUT … it delivers the nearest you can get to 100% alerted traffic for IFR and VFR … and most particularly IFR RPT! .. that is what the discussion is about is it not?

… Well, isn’t that what CTA is for? a third party who is trained and rated to provide a standard of services that will only alert you when there is a reason to i.e. ‘relevant’ threat traffic when it is necessary .. as I said earlier, if a separation ‘standard’ exists between you and other IFR or VFR, ATC won’t load the frequency with traffic information on aircraft that are no threat to you.

It would require at least one FSO to handle the traffic in the Whitsunday CTAF(R) alone - with the amount of traffic at Shute Harbour, Whitehaven, the Molle Group / Long Island Sound and Hardy Reef the discrete frequency would be jammed at times, especially when the FSO is trying to pass the traffic to five or so aircraft that happen to be at just one of these locations. Does the IFR RPT need to know about any of this traffic - absolutely not unless the pilot is making up his own approach or departure procedures. If they're in the murk in these areas they've either flown through or just missed cumuli granatis to get from the approach to these locations.

Just last week, the tower did not pass traffic to me that was on a converging course at the same altitude to a common location just outside CTA and a similar estimate. Was it a problem - no - I heard his call to ATC and the other pilot heard mine. ATC did pass a following aircraft on a diverging course to me though.

So being able to hear and understand traffic calls and how they relate to you (SA) is an essential skill, especially in areas where there is a high density of VFR traffic. In VMC the mark one eyeball is supposed to be the primary piece of collision avoidance equipment - I prefer not to rely on it as the only method.

come and spend some time plugged in listening to the results of the last ten+ years of GA and in particular VFR disengagement with ATS … BFR’s and other standards and mechanisms for proficiency in radio telephony are not working terribly well, particularly where that pilot instruction is mostly outside ATS areas!

VFR pilots are being told to shut up and look by the current documentation, unless hearing conflict from IFR or participating in a RIS. Every change to VFR procedures seems to reduce interaction with ATS in E & G. Is it any wonder pilots are becoming more reluctant to talk on the radio? Is it good? - definitely not. Is it understandable? - yes.

ATC do not close the zone for SVFR ..sport!

At YBHM you will not get a special VFR clearance if there is any other IFR or SVFR aircraft in the zone full stop. It's as certain as death or taxes.

If you were permitted to operate closer than 1000ft vertically from cloud in CTA, …. who gets fecked over? … IFR, ATC and VFR (you) because you will not get a clearance that will leave an arriving IFR in cloud over the top … sorry n’ all!

If I can't operate closer than 1000ft vertically from cloud in CTA I get over anyway because I need a 1600' cloud base to operate. I have no problems with being procedurally separated and having to wait (even outside the zone) - fifteen minutes holding doesn't cost as much as not being able to work.

Now if you are SVFR and you lodge a plan that tells us you can use a VOR, or DME .. that’s a different story!

Firstly, VFR aircraft can ONLY navigate by visual reference to ground or water when below 2'000AGL (refer AIP ENR 1.1 19.2). Secondly, the islands block the NAVAID signals through most of YBHM zone even at 1,000AGL.

.. with you lurkin around below the cloudbase or in marginal visibility ol’ cock … hope your TXPDR is on and accurate and the big guys are nice and slow early!

Radio is required to be used when operating at a reduced distance from cloud in G even without CTAF(R) procedures (The only time fixed wing VFR flight is permitted in less than 5000m visibility is in controlled airspace with a special VFR clearance). You can be damn sure I will be communicating anywhere when I'm anywhere near the instrument approach paths and associated areas if I am close to cloud in "G". If an IFR is shooting an approach I will keep out of their way - the last thing I want is to be hit by another aircraft (even though CAR 162 (5) requires the higher aircraft to give way to the lower aircraft).

ACAS as far as I am concerned is a measure of last resort - if an aircraft has to respond to a RA to avoid a collision - there has been a major failure in the system. Interestingly transponders are not required to be fitted in either G or D (in the aircraft I fly they are fitted, calibrated as required by AD/RAD whatever and are switched on in any wx).

OK, lets just get scientific and objective about airspace and keep the emotion out of it. CASA (as the regulator) should be required to do proper scientifically based risk assessments before allowing changes to be made to airspace. It's a looong post I know, but its been a good exercise to flick through the docs to verify the rules.

W

BTW I believe one piece of technology that has increased the risk of collision between VFR aircraft is the humble GPS. With the accurate tracking provided, VFR aircraft are concentrated closer to the direct track than they used to be in the days when DR was king.

[werbil]

Scurvy.D.Dog

I just checked your profile and see you are ATC. Which is fine, but the way you replied I assumed that you had personal experience flying in "G". Are you or have you been a pilot as well? If not, I hope your comments about what you think pilots can manage in "G" are based on something substantial.

Given the classes you control I have to assume you work where the airspace is generally quite busy with IFR traffic. It just isn't like that all over Australia. If you are up this way PM me and I may be able to give you a ride and a headset so you can hear what actually happens.

FYI sometimes seaplane pilots can manage five frequencies on a five minute sector - marina (clearance to water taxi through), CTAF, Tower, Marine (coordinating approach to boat) and company (SAR's, operational changes). And remember this is single pilot with four different traffic situations to assess ("D", CTAF(R), departure water and arrival water) - and water wakes can be just as dangerous as wing tip votices. Two pilots should be able to manage the same number of frequencies even in IFR.

And a final pilots 'understanding the airspace classes' comment - maybe pilots are confused between D & C because in some "D" airspaces the usual practice is for ATC to separate (or segregate) VFR from IFR as is required in "C". At YBHM I have only heard pilots made responsible for ensuring "segregation" between VFR & IFR aircraft after both aircraft have sighted each other - yet VFR to VFR is just given traffic. Have a look at ATSB comments in Jan/Feb Flight Safety Australia page 58 and May/June Flight Safety Australia page 59 - ATC contributed as well as the pilots.

W

[Scurvy.D.Dog]

Werbil I have again used individual quotes, this time mainly to be as patronising as you in return

Fundamentally, I am sure we are going to agree to disagree on a number of issues - I am assuming we operate in two very different sectors of aviation. I fly float planes (including turboprops) in single pilot VFR SE charter (yes I carry pax, transponder and carry carriers liability insurance). I am assuming that you fly either RPT or corporate pure jet because of your responses

… agree or disagree is irrelevant .the efficacy of the argument is the important bit. The fact that you assumed I was RPT or Corp is telling … I guess you perceive/assert that I ‘only’ see the issues from fast RPT IFR perspective? … not even close .. more on that later!

(or possibly ATC - but if so you should have advised this in your response).

.. it is in my profile, not to mention it being common knowledge in this place for a number of years … but then, again it is irrelevant …. as irrelevant as where and what you fly .. although now you mention it, your responses point to that in any case!
.
… content not motherhood statements eh?! .. on that note:-

When full reporting for VFR ceased in the early 90's it was a culture change - we had to learn to listen for calls from other aircraft.

…. Yep, no mean feat given half the traffic went silent en-route OCTA … less positional SA on VFR’s, IFR’s OCTA mixed up (freq wise) with ATC services being provided to aircraft in CTA above/adjacent .. yep a real boon for pilot SA OCTA AND in CTA (frequency loading) ..not withstanding … big sky theory (un-alerted see-and-avoid) was deemed appropriate for IFR/VFR/VFR OCTA in sparsely traffic’d areas … ships in the night on a big ocean!

And then when NAS was introduced VFR aircraft were expected to remain silent on center frequencies in "E" & "G" unless in conflict with an IFR aircraft.

.. daft idea ya think then?

The fundamental problem I have with this system (in both "E" & "G") is that it requires the VFR pilot (who is probably less experienced) to not only have the correct frequency selected, but also have the volume set appropriately and have enough SA to understand if the aircraft is in conflict.

… what percentage of VFR know the IFR stuff (including radials, holding patterns, sector entries, and approaches) in any given location? .. ppppplease …VFR remaining clear of IFR routes when transiting over/around/across terminal and enroute surrounds is a practical impossibility! Add to that … VFR being blind to ATC and IFR in E … OK … so run by me again why

I personally believe that "E" is a great airspace classification - I just think that it is poorly implemented in Australia.

…. WTF?? … you also said

If this fails, with a 250 knot closing speed (theoretically could be 500 knots B100) and 5000m clearance from cloud both aircraft could be "sharing" the same airspace in under 12 seconds from the first possible opportunity for visual acquisition.

… errm what does class E deliver you then?? …. Mate pick a position and stick with it … a bob each way don’t cut it! .. never seen anyone try to argue both sides of a debate at once …… errrmmm then again … maybe one other!

And remember transponders are only required to be fitted in "A" and "C" airspace, above 10000ft (except gliders) and in "E" airspace if the aircraft has an engine driven electrical system, and radios are not required in G B050 (except CTAF R's) or for gliders. No radio, no transponder at 1000' - seriously is this a problem over a station strip in the middle of the outback - no, would this be a problem over YBBN - oath it would be.

.. lotsa words stating the bleeding obvious, I don’t think any of us need a lecture on basics …..citing two irrelevant extremes (which are outside the current discussion) is a waste of bandwidth and a tad insulting to the many here who already know **** from clay!! .. lets focus on the areas of relevant discussion shall we? i.e.
.
- Class D (no TXPDRS required BTW) … you seem to know .. you tell me why!
- Outback station strips ….. not what the discussion is about is it! .. it is about CTA rules and OCTA rules particularly where RPT operate i.e. CTAF(R) and low level regional CTA
.
Back to the issues

Yes a third party directed traffic service does remove some of the risks, but it still requires accurate position information from ALL pilots to work.

.. errrm how is that achieved in E?
… smarter minds that you and I will determine the answer/s based on factual data and then consider the cost and safety benefit compared to the status quo! …. The options and outcomes from the variables is what we are musing is it not?

I don't believe that anyone involved in aviation would for a second seriously suggest that all of Australia should be covered by radar "B" or "C" airspace

.. again, making a statement against an absurd suggestion such as blanket radar “B” and “C” (that no one else has suggested should occur) … does not point to a comprehension of the specifics …. Or, might be seen as an attempt to misrepresent points of argument … either way, that sort of ‘mudding’ will not slip through to the keeper in this place! … for the record though:-
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… I have never, nor would I ever suggest that radar B and C airspace should be installed all over Australia. If you had bothered to read the many pages of debates in this place on these issues, you would know (perhaps you do) that I argue that where enroute SSR radar can be replaced with WAMLat/ADS-B it should! Why?
.
..it is solid state, cheap as chips (comparatively), with little ongoing maintenance … AND … (subject to an identified need - in CTA or OCTA), could be funded by the savings made from not having to service/replace existing or future radar heads.
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Just so we are clear ..Only installed to replace existing radar and where future surveillance (at WAMLat prices) is desired/required, rolled out to improve CTA and OCTA services!

- this would be simple for pilots - one procedure, and give the lowest risk for breakdown in separation - but imagine the cost.

yes imagine the cost …. good thing no one is suggesting it!

My recollection is that alphabet airspace was introduced to harmonize Australian procedures with other countries (make it simpler for overseas pilots). Alphabet airspaces does not include a system the matched the old OCTA system -(directed traffic to and about all aircraft including VFR).

.. nor is there an alphabet ICAO G classification that includes IFR DTI .. so what! .. member states to the Chicago convention may operate their systems (lodge differences) as they see fit! .. in any event, how ridiculous (in hindsight) to have attempted harmonisation (which it never was, as has been demonstrated over and over) when ‘those (other) countries’ such as Europe are likely to harmonise on a system similar to the one we use to have i.e. CTA and OCTA ….. how much money, pilot confusion and consumer confidence has ABC airspace cost us???? ….. just so OS pilots could use it? …… bollocks … few OS pilots fly in this country outside the primary capitals … and, for the handful of tourist pilots … the old system was completely compatible …. No .. it was changed for other reasons … harmonisation was just the excuse!

OK, so now I am getting to the crunch. Traffic, and location being equal, the earlier the letter the lower the risk of collision in the airspace should be. I think that the old OCTA system is closest to either "D" airspace (except IFR receives traffic information rather than a separation service) or "F" airspace (except all aircraft receive a traffic information service).

nup OCTA F was nothing like D CTA as both VFR and IFR are known in CTA D, IFR/IFR are ‘separated’, and receive as a minimum IFR/VFR/VFR DTI (alerted see-and-avoid) … not in F (IFR/IFR DTI only) … the old OCTA system of VFR and IFR DTI does not conform to any ICAO alphabet classification … does it mean that alerted VFR was not a good idea NO … over the top … maybe …. onerous (radio) … maybe …. ADS-B will do the same once fleetwide is achieved … don’t get me started on that .. It’s already been done here … do us all a favour and look it up

So the risk of collision between a VFR and any other aircraft is now probably greater in both "E" and "G" airspace

.. how silly would that be to ‘refine’ a system and make it potentially less safe? …. by Jove …. as far as AUS E and G go, IMHO you might just be on to something!
If your assumption is correct ... how were the changes (AMATS, Airspace 2000 and all iterations since) justified against risk management criteria if risk may have increased ... one assumes an offset cost benefit? …. I would love to see a fair dinkum comparison of the number of operator positions back then (CTA ATC and OCTA FS) compared to today (after compensating for CTA traffic growth over that time against the ‘comparative’ cost/purchasing power)!
How can it be eh? .. hmmm … I can think of a common denominator … can you?

the risk of collision between two IFR aircraft is now probably higher in "G" airspace and lower in "E" airspace.

…. that assumes there is/was a data set that supported the notion that DTI to IFR (and self arranged segregation) in OCTA F produced airprox/collision incidents sufficient to trigger a change in classification that involves ATC intervention (CTA E)?! … if you can find and provide that data .. we would be much enlightened! .. I bet you can’t!
Not withstanding … even if IFR pilots OCTA had experienced ‘un-alerted’ or even ‘alerted’ airprox’s in OCTA F sufficient to warrant a change in service level, areas that were made G would/should have been made E, D, or higher .. i.e. an increase in service level not a reduction to G!
…. No the reason was to remove the supposed cost of Flight Service Officers (DTI OCTA) … Dick Smith (the then Chairman of the CAA) is most proud of that change …. A change that meant ATC’s took on the FS function OCTA on top of the CTA ATC function … peachy
… what do you reckon that has produced for IFR and VFR OCTA?, not to mention RPT in the higher levels that cannot get a word in edgeways (often) due the OCTA FS/IFR DTI function below! …. and the poor bloody ATC line controllers … ever since, re-sectorised, restructured, expected to do more and more with less and less ….. don’t get me started on that issue!

Two IFR aircraft means that both aircraft could be in cloud removing any possibility of a collision being avoided by "see and avoid". In other words I am NOT convinced that the old OCTA system was safer than class E airspace for IFR aircraft.

…crap …. 2 IFR pilots in conflict routinely segregated using levels and distances … 100% perfect … no …. Better than E … I reckon … particularly when you add in delay costs of procedural separation in E at low level and not knowing about VFR!
.. as for the reasons ATC E (outside surveillance areas down to MSA/LSALT’s) delays IFR .. it has been explained here so many times …. do some reading!

Secondly, flexibility in airspace procedures is essential because the usage of airspace is different. Where there is a large number of RPT, airspace procedures should be optimized for IFR - "C" or "B" are logical and obvious. Where there is no reasonable possibility of IFR (ie no approach procedures) airspace procedures should be optimized for VFR. The difficult ones are places which has only a few jet or IFR movements a day (like YBPN which has little other traffic or YBHM which has a large amount of VFR traffic).

…. Round we go again ….. it is not difficult, read the suggested remedies!

The reason I suggested a multicom system is to allow VFR aircraft to broadcast their position and intention to other aircraft on a routine basis. Actually I would prefer the old system where VFR aircraft were encouraged to routinely broadcast on the center frequency, but now days this is very much discouraged (according to the AIP) except when responding to a conflicting IFR aircraft.

… again why do suppose that is …. Frequency loading … why is frequency loading an issue …. Join the dots dude!

Yes level banding has its limitations, but it will reduce the radio clutter from distant, high altitude traffic, and every aircraft has an altimeter that tells the pilot when to change frequencies.

… bollocks … lets poll the IFR drivers on here (that descend into and climb out of CTAF in to and out of CTA each day) shall we? ….. in fact it is not necessary … the multicom idea nearly killed people a number of times during the G airspace trial (suspended for same by CASA at ATSB/BASI recommendation)

The intention of my suggestion is that CTAF calls would be made on the B050 multicom frequency (except where a discrete CTAF frequency is established)

so there is two frequencies below A050, 3 if you are IFR talking to ATS for IFR DTI

to reduce the number of frequencies that have to be handled.

.. how is it less frequencies than to day or the proposal I have put! … just answer that without the waffle!

Remember the days of frequency after frequency being retransmitted by ATC - if you weren't getting directed traffic the bloke at the other end of the state could be loader and clearer than the other guy only 20nm away.

… remember the days …. Fark me … have you listened to the ATS frequencies of late? …. ‘the days’ are now .. not the past!

As for the RPT drivers - establish class C or D wherever you like - just don't ask me (or my pax) to pay for it in areas where it cannot be justified.

… typical rhetoric of the old guard …. No one is saying C or D where it is not justified … and as it is FREE for VFR in CTA (unless it is associated with an aerodrome for which the TWR is associated, and even then it is a piddle compared to most of your costs) … whining about getting a safety service for free …. Bout says it all … suppose it is too much to consider the IFR’s you pontificate about above … or is all that just hot air!

I will use it if it is there to access the airspace, but I am happy in G. I would be much happier when in either E or G to be able make regular broadcasts that all other pilots can hear when en route though.

…. Make up yer mind cobba!

DRA's are still in CAO 20.11 - they're just less relevant as all aircraft have to carry an ELT now days anyway. I don't remember the radio procedures being any different - my hazy memory is that you had to broadcast on the area VHF frequency and if operating full reporting report on HF when outside VHF range or lodge a SARTIME and carry an ELT if you didn't have HF - does this sound right?

DRA’s are (or should be) for all intents and purposes ‘proper’ ICAO G i.e. … IFR and VFR get nothing!

It would require at least one FSO to handle the traffic in the Whitsunday CTAF(R) alone - with the amount of traffic at Shute Harbour, Whitehaven, the Molle Group / Long Island Sound and Hardy Reef the discrete frequency would be jammed at times, especially when the FSO is trying to pass the traffic to five or so aircraft that happen to be at just one of these locations.

…. FSO is not gunna pass traffic to 5 or so VFR otherwsie it would be D. They will however pass IFR traffic to other IFR. That’s why a visual scan is still required (see-and avoid) for VFR and IFR pilots OCTA …. BUT … If you were paying attention, I have suggested the OCTA DTI service provider (where it is available)

[Scurvy.D.Dog]

would have access to surveillance data for the provision of DTI (only that which is relevant) … less frequency loading and only relevant traffic …

Does the IFR RPT need to know about any of this traffic - absolutely not unless the pilot is making up his own approach or departure procedures.

landing yer duck next to islands is one thing .. again not really relevant other than VFR/VFR! What is relevant is the aerodromes where IFR and VFR operate in the immediate area and can come into conflict … if there is a group or aerodromes in a vicinity, one of which services IFR RPT i.e. CTAF (R), put them and the surrounds on the OCTA FS freq and the others on separate CTAF freq if necessary … IFR RPT protection is the name of the game! …. In any event our ‘opinions’ on frequency loading and appropriateness in any given area is irrelevant .. it needs careful assessment ‘independent’ assessment!

If they're in the murk in these areas they've either flown through or just missed cumuli granatis to get from the approach to these locations.

… not if you are using the same airport .. come on mate, lets get real about this!

Just last week, the tower did not pass traffic to me that was on a converging course at the same altitude to a common location just outside CTA and a similar estimate.

.. not the towers job description

Was it a problem - no - I heard his call to ATC and the other pilot heard mine. ATC did pass a following aircraft on a diverging course to me though.

.. is the towers job description … if in or leaving CTA … this is becoming tiresome!

So being able to hear and understand traffic calls and how they relate to you (SA) is an essential skill, especially in areas where there is a high density of VFR traffic. In VMC the mark one eyeball is supposed to be the primary piece of collision avoidance equipment - I prefer not to rely on it as the only method.

…. Have you caught-up with your tail yet

VFR pilots are being told to shut up and look by the current documentation, unless hearing conflict from IFR or participating in a RIS. Every change to VFR procedures seems to reduce interaction with ATS in E & G. Is it any wonder pilots are becoming more reluctant to talk on the radio? Is it good? - definitely not. Is it understandable? - yes.

.. and who’s fault is that?

At YBHM you will not get a special VFR clearance if there is any other IFR or SVFR aircraft in the zone full stop. It's as certain as death or taxes.

… depends on your track and geographical features on which ATC can base separation …. Have you considered the amount of ‘blue’ topography around the YBHM zone … how often to you track via points that assist ATC in this regard … hmmm?

If I can't operate closer than 1000ft vertically from cloud in CTA I get f#@ked over anyway because I need a 1600' cloud base to operate.

..not what you said before … or are you saying that if the base is 1600 AGL you can operate at A015 except in CTA?? ..careful with the answer

I have no problems with being procedurally separated and having to wait (even outside the zone) - fifteen minutes holding doesn't cost as much as not being able to work.

15 minutes eh … how many time are you NOT delayed each year V’s delays? … selective negatives stick out like pooch jubes!

Firstly, VFR aircraft can ONLY navigate by visual reference to ground or water when below 2'000AGL (refer AIP ENR 1.1 19.2). Secondly, the islands block the NAVAID signals through most of YBHM zone even at 1,000AGL.

… who said anything about being VFR below A020? … or is that your normal operating altitude?

Radio is required to be used when operating at a reduced distance from cloud in G even without CTAF(R) procedures

.. yeh sure they use the radio

(The only time fixed wing VFR flight is permitted in less than 5000m visibility is in controlled airspace with a special VFR clearance).

… you’ve worked that out then … want to revisit your original question?

You can be damn sure I will be communicating anywhere when I'm anywhere near the instrument approach paths and associated areas if I am close to cloud in "G".

… carry IFR charts whilst VFR do ya?

If an IFR is shooting an approach I will keep out of their way - the last thing I want is to be hit by another aircraft (even though CAR 162 (5) requires the higher aircraft to give way to the lower aircraft).

… farken ell

ACAS as far as I am concerned is a measure of last resort - if an aircraft has to respond to a RA to avoid a collision - there has been a major failure in the system.

… no **** Sherlock …. Aus NAS 2b Class E Launy Christmas Eve 2003 … pax down one side of the B737 saw the face of the pilot of the TOBA as he passed under the wing … had the TXPDR of the TOBA been off or out by 300ft or the jet crew not respond to the RA .. there likely would be a memorial each year on Christmas eve in Launy ….. FOR WHAT POSSIBLE REASON would you change C to E in this case?

Interestingly transponders are not required to be fitted in either G or D (in the aircraft I fly they are fitted, calibrated as required by AD/RAD whatever and are switched on in any wx).

…. Good for you, so do most others … why is it you religiously do so? … hoping to avoid a surprise?? .. of course it is!
… and for the last feckin time D do NOT require TXPDRS below A045 as the Tower Controller can apply Procedural standards most often Visual Separation …. It gives safe access to D aerodromes for non-transponder equipped aircraft!. I thought that was obvious to all!

OK, lets just get scientific and objective about airspace and keep the emotion out of it.

.. are you being patronising? … if so that is rich and hypocritical given the inconsistent clap trap I am sitting here responding to … which I might add, I am doing for others benefit!

CASA (as the regulator) should be required to do proper scientifically based risk assessments before allowing changes to be made to airspace.

.. no one is saying anything different …. Is that clear enough yet?

It's a looong post I know, but its been a good exercise to flick through the docs to verify the rules.

… yes, I just love quoting reams of rules and procedures over and over again when the water has turned to swamp from ****!

BTW I believe one piece of technology that has increased the risk of collision between VFR aircraft is the humble GPS. With the accurate tracking provided, VFR aircraft are concentrated closer to the direct track than they used to be in the days when DR was king.

…. Oh come now, if un-alerted see-and-avoid works A OK, why would GPS be a problem …. Or is it that see-and-avoid does not often work, rather the big sky theory does …. OH bugga eh!

I just checked your profile and see you are ATC. Which is fine, but the way you replied I assumed that you had personal experience flying in "G".

I do, and the old OCTA F as well

Are you or have you been a pilot as well?

yup (as many who contribute here know)

If not, I hope your comments about what you think pilots can manage in "G" are based on something substantial.

…. Not that it matters but 22 years and 17 ATS

Given the classes you control I have to assume you work where the airspace is generally quite busy with IFR traffic. It just isn't like that all over Australia.

… yet again, don’t put words in my keyboard fella .. it ****s me more than listening to Howard

If you are up this way PM me and I may be able to give you a ride and a headset so you can hear what actually happens.

.. operated up and down the QLD coast some years ago, know the architecture of most D/C TWR’s (as the SATC’s are ‘like type’ colleagues) I am in touch with regularly. I am Check and Standards for D/C TWR/APP, as well as an ATS Investigator. I have been fortunate to have made many famil rides in most things from C404’s, through B767’s .. and have spend many a day providing CA/GRS and Unicom services at many airshows (6.5 years at YSBK came in handy for the airshow stuff) … I think (at a guess) I am full bottle on frequency management … thanks all the same though!

FYI sometimes seaplane pilots can manage five frequencies on a five minute sector - marina (clearance to water taxi through), CTAF, Tower, Marine (coordinating approach to boat) and company (SAR's, operational changes). And remember this is single pilot with four different traffic situations to assess ("D", CTAF(R), departure water and arrival water) - and water wakes can be just as dangerous as wing tip votices.

… good for you, so you should when that is primarily the same areas you always operate in

Two pilots should be able to manage the same number of frequencies even in IFR.

… yeh right, specially when an IFR crew are likely to be outa towners …. Think man!

And a final pilots 'understanding the airspace classes' comment - maybe pilots are confused between D & C because in some "D" airspaces the usual practice is for ATC to separate (or segregate) VFR from IFR as is required in "C".

…. If you are gunna make statements in the ‘absolute’ check yer facts first:-
- In C IFR AND VFR are Separated
- In D IFR and VFR need not be ‘separated’, ATC will separate where able and segregate with traffic info if a critical collision risk does not exists!
note …. ATC in this country have been made very aware that ‘traffic information’ in CTA D (whether it is IFR/VFR or VFR/VFR) may not be enough if two subsequently go together …. The problem for us is spending years in all sorts of enquiries justifying why we did not ‘prevent the collision’ as part of the definition of an ‘Air Traffic Control Service’ (ICAO, CASR, MATS and AIP)
… look it up!
…. Unless we are to busy to separate or segregate (and can justify that decision after the event) WE WILL MAKE YOU MISS EACH OTHER ….. is that clear enough?

At YBHM I have only heard pilots made responsible for ensuring "segregation" between VFR & IFR aircraft after both aircraft have sighted each other - yet VFR to VFR is just given traffic.

.. ah dear
.. the first example is pilot assigned ‘visual separation’ .. this is a ‘separation standard’ in the books
.. the second fall into the category explained above

Have a look at ATSB comments in Jan/Feb Flight Safety Australia page 58 and May/June Flight Safety Australia page 59 - ATC contributed as well as the pilots.

… there is more than one line I could use here, but at the risk of offending many … I shall refrain!!
.
… lets end the pissing contest shall we …. I'm bored ..... and I am dam’d sure everyone else has fallen asleep or committed hairycary!
.
Nite to those still breathing!

[werbil]

Scurvy.D.Dog,

Some last comments.

IF YOUR GOING TO QUOTE ME, QUOTE ME IN CONTEXT - DON'T SELECTIVELY QUOTE PARTS FOR YOUR OWN PURPOSES.

If you read my arguments CAREFULLY, you will see that there are numerous points that we agree on. It was your argument that there should only be two classes of airspace (plus DRA's). My arguments are WHY I believe it wouldn't work and my reasons, and some comments about the way airspace is implemented. I was replying to the thread - other people may be following it.

I have not seen ONE positive comment by you about the competence of a VFR pilot in this thread. A person's background and experience does influence the way I evaluate their arguements, which considering the points you were making makes your background relevant.

D airspace is the currently the first airspace which has any VFR involvement with a third party for traffic purposes (except CA/GRS or UNICOM). Old OCTA had VFR involvement with FS - that is THE similarity I was referring to.

Re YBHM (1) - a VFR aircraft at A010 cannot physically be traffic for an IFR aircraft outside 6 nm YBHM very conservatively between the 000 and 090 radials (no circling to NE of AD and you don't have to be a rocket scientist to work out why). Yet in the area around 7nm to the NE (Whitehaven) there can be numerous VFR aircraft that are significant traffic to each other. This area is covered by a discrete CTAF(R) that also includes Hardy Reef, YSHR, Long Island Sound and Hayman Island underneath the CTA which has high densities of VFR traffic. When the tower closes for lunch and at night the reclassified airspace becomes part of the discrete CTAF(R) - there may be an arguement that it should be left as a CTAF(R) using the tower frequency.

Re YBHM (2) - converging heading was to the same waypoint approx 1nm outside the zone and we both arrived there within about a minute. Traffic whilst still in CTA ? - oath it was. Requirement to pass as traffic - I think so.

Re YBHM (3) - locations - Very few of the locally used waypoints are included on the VTC. ATC know where they are - they use them as clearance limits on a regular basis. Over a beer one evening one of the local controllers told me there is a chart in the tower that depicts them - and he named a few I that I didn't know where they were.

Re 1500' AMSL CLEAR of cloud in G - perfectly legal providing pilot uses radio as required.

Re E - If it's so dangerous / impractical it wouldn't work anywhere else in the world. Quoting myself (with emphasis):

I personally believe that "E" is a great airspace classification - I just think that it is poorly implemented in Australia.

And your argument is?

And a final comment - the local controllers are approachable and I can have a healthy discussion with them about airspace without it denigrating into a fight. Professionalism maybe?

W