Voices of Reason and Class E
According to the Prelim, the Jab pilot broadcast to Lismore traffic he was 4 east of Lismore, 5300ft and descending. The Jet didn't hear it and there is no evidence the CA/GRO did either. In any case, the CA/GRO is employed to provide traffic at BNA, so traffic broadcasting to Lismore, which he probably hears all day, is irrelevant, especially if it sounds like he's inbound to Lismore.
As an aside, in the old quadrantal days, those two aircraft on those tracks (in cruise) would have crossed with a minimum of 500' separation and no one would have batted an eye.
As an aside, in the old quadrantal days, those two aircraft on those tracks (in cruise) would have crossed with a minimum of 500' separation and no one would have batted an eye.
Last edited by Traffic_Is_Er_Was; 19th Apr 2021 at 22:51.
TIEW - I too am waiting to find out if the CA/GRO heard the transmission from the Jab, however, I do not agree with your conclusion.
1. If the CA/GRO knows the tracks of both aircraft then he/she knows they will intersect, regardless of the directed broadcast from the Jab, so they are mutual traffic. That is why the aerodromes share a CTAF.
2. 500 feet vertical in cruise is a far different risk to 600 feet with both aircraft on descent. The second is pure chance.
The incident has also proven that for Australia to rely on TCAS to avoid providing ATC is going to end in tears.....
1. If the CA/GRO knows the tracks of both aircraft then he/she knows they will intersect, regardless of the directed broadcast from the Jab, so they are mutual traffic. That is why the aerodromes share a CTAF.
2. 500 feet vertical in cruise is a far different risk to 600 feet with both aircraft on descent. The second is pure chance.
The incident has also proven that for Australia to rely on TCAS to avoid providing ATC is going to end in tears.....
Geoff,
Chance ? I agree, I used the word Providence in a post on the incident several weeks ago.
Are you sure the relevant aircraft were not on radar?
I seem to remember a post of yours in regard to Ballina re the non display of SSR tracks due track duplication with ADSB tracks on the CAGRO’s “air situation display”.
Perhaps I misunderstood. If I did I was not the only PPRUNE reader who took it that way? If I misunderstood what were you referring to?
AsA’s published radar coverage dictates I at least ask the question...The facts should have been in the ATSB report.
Given your accusation that AsA is using a airborne based safety net in lieu of ATC based procedures (surveillance or procedural methods), ( an accusation I have sympathy for by the way and not just in G airspace) could you simply explain to me (and other readers)in a sequential list of processes how E airspace NAS version would have prevented this incident from occurring.
I think it would be very educational.
Don’t worry I wont ask you to do the same for MNG but others might...
Thanks in advance!
Gentle_flyer
Chance ? I agree, I used the word Providence in a post on the incident several weeks ago.
Are you sure the relevant aircraft were not on radar?
I seem to remember a post of yours in regard to Ballina re the non display of SSR tracks due track duplication with ADSB tracks on the CAGRO’s “air situation display”.
Perhaps I misunderstood. If I did I was not the only PPRUNE reader who took it that way? If I misunderstood what were you referring to?
AsA’s published radar coverage dictates I at least ask the question...The facts should have been in the ATSB report.
Given your accusation that AsA is using a airborne based safety net in lieu of ATC based procedures (surveillance or procedural methods), ( an accusation I have sympathy for by the way and not just in G airspace) could you simply explain to me (and other readers)in a sequential list of processes how E airspace NAS version would have prevented this incident from occurring.
I think it would be very educational.
Don’t worry I wont ask you to do the same for MNG but others might...
Thanks in advance!
Gentle_flyer
Last edited by Gentle_flyer; 20th Apr 2021 at 04:10.
To 'rely' on T C A S = T E A R S .........
Stated over 20 years ago.....So....What's changed..??
NO CHEERS HERE....NOPE...NONE AT ALL...!!!
Stated over 20 years ago.....So....What's changed..??
NO CHEERS HERE....NOPE...NONE AT ALL...!!!
GF - Thanks for the question, the short answer is that Class E would not have prevented or even mitigated the incident at Ballina. I will try and keep the longer answer as short as possible.
Class E exists because the FAA believes that IFR flights should always be in controlled airspace. This is linked to an ICAO requirement for instrument approaches to be contained in controlled airspace. For instance, take the UK, until RNAV came along an aerodrome with an instrument approach had to also have a control tower. (Admit to being out of touch now that RNAV available), The US solves that problem with Class E airspace because they have many aerodromes that do not warrant a control tower, just like Australia....
That is why I maintain that Class D airspace and a control tower is required at Ballina. The Tower would be the equivalent of an FAA VFR Tower because the Class E airspace surrounding it would require Brisbane Centre to control IFR approaches and separate IFR aircraft. When the Centre has solved whatever IFR separation problems exist then the inbound aircraft is transferred to the Tower which is responsible for separating the VFR aircraft from the IFR. Hamilton Island manages to do this with one controller while separating IFR and VFR aircraft, hence costs are kept as low as possible.
If there is no Tower then the IFR pilot needs to listen on the CTAF and self separate with VFR traffic. If maneuvering is required by the IFR aircraft then it should be able to be accommodated by the Centre controller, however, if the clearance is via an instrument approach that may require a go-around. IFR aircraft can also make visual approaches if they have the aerodrome in sight. In fact, I believe that if an IFR aircraft reports the aerodrome in sight, in the US that automatically generates clearance for a visual approach. If IFR aircraft are consistently having separation problems with VFR traffic then very likely a Tower is required.
I hope this is useful
Class E exists because the FAA believes that IFR flights should always be in controlled airspace. This is linked to an ICAO requirement for instrument approaches to be contained in controlled airspace. For instance, take the UK, until RNAV came along an aerodrome with an instrument approach had to also have a control tower. (Admit to being out of touch now that RNAV available), The US solves that problem with Class E airspace because they have many aerodromes that do not warrant a control tower, just like Australia....
That is why I maintain that Class D airspace and a control tower is required at Ballina. The Tower would be the equivalent of an FAA VFR Tower because the Class E airspace surrounding it would require Brisbane Centre to control IFR approaches and separate IFR aircraft. When the Centre has solved whatever IFR separation problems exist then the inbound aircraft is transferred to the Tower which is responsible for separating the VFR aircraft from the IFR. Hamilton Island manages to do this with one controller while separating IFR and VFR aircraft, hence costs are kept as low as possible.
If there is no Tower then the IFR pilot needs to listen on the CTAF and self separate with VFR traffic. If maneuvering is required by the IFR aircraft then it should be able to be accommodated by the Centre controller, however, if the clearance is via an instrument approach that may require a go-around. IFR aircraft can also make visual approaches if they have the aerodrome in sight. In fact, I believe that if an IFR aircraft reports the aerodrome in sight, in the US that automatically generates clearance for a visual approach. If IFR aircraft are consistently having separation problems with VFR traffic then very likely a Tower is required.
I hope this is useful
Bit off topic but dropped into Ballina again yesterday and there seem to be more RPT then before Covid. Pelican down to Newcastle. Jetstar and Virgin duplicating flights to Melb/Syd. Rex too now. Not many people in the terminal so can guess load factor is low. Radio congested mainly because the poor GRO was being particularly pedantic about passing on every bit of traffic to everyone in turn, so was hard to actually get a call in. (Not blaming the GRO, i am sure they have been put under a lot of pressure and that is his job and they do a bloody goon one in my opinion, just too much RPT.)
I really think Ballina is way over serviced with RPT now. It's a town little more than half the size of Dubbo but every low cost airline is there all the time. Sure Byron is down the road...but so is the Gold Coast and it has a lot more capacity then Ballina.The airline industry is being subsidized by the Govt at the moment, so there is oversupply. A friend said they flew down to Newcastle for $49. No wonder there is congestion if you can fly somewhere for less than a third of the cost of fuel to drive there. Yet the airlines are agitating to lock up the airspace to recreational users so they can fly people down to Newcastle/Sydney for less than a carton of Corona. It's not an essential service, we don't need more instagramers here. Its just a distorted market.
The simple solution would be to stop subsidizing these flights, let the market do its thing. There is a big International airport just an hour drive away. Lismore 30 mins away. It won't happen of course, but that is the best solution.
I really think Ballina is way over serviced with RPT now. It's a town little more than half the size of Dubbo but every low cost airline is there all the time. Sure Byron is down the road...but so is the Gold Coast and it has a lot more capacity then Ballina.The airline industry is being subsidized by the Govt at the moment, so there is oversupply. A friend said they flew down to Newcastle for $49. No wonder there is congestion if you can fly somewhere for less than a third of the cost of fuel to drive there. Yet the airlines are agitating to lock up the airspace to recreational users so they can fly people down to Newcastle/Sydney for less than a carton of Corona. It's not an essential service, we don't need more instagramers here. Its just a distorted market.
The simple solution would be to stop subsidizing these flights, let the market do its thing. There is a big International airport just an hour drive away. Lismore 30 mins away. It won't happen of course, but that is the best solution.
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Good explanation.
There's only one hick-up... IFR and VFR is not separated in class D airspace. The separation the tower controller is responsible for is the "runway separation", which means he shall make sure there's only one aircraft on or over the runway at any time (which is not entirely correct, but can do as a rule of thumb). VFR and IFR will be provided traffic information about each other.
At the moment you establish a control tower, you can have one controller working at very low density airports. But still consider that the person would need breaks etc. Furthermore, the staffing need to be higher, since that one person would still need days off, vacation etc. So you'd need maybe 3 controllers to staff a unit.... On top of that you'd need an approach setup at the centre, which technically can be done by the sector covering the area, but still it's a task someone has to do etc. etc.
Setting all this up is not just one controller cheap and easy.
There's only one hick-up... IFR and VFR is not separated in class D airspace. The separation the tower controller is responsible for is the "runway separation", which means he shall make sure there's only one aircraft on or over the runway at any time (which is not entirely correct, but can do as a rule of thumb). VFR and IFR will be provided traffic information about each other.
At the moment you establish a control tower, you can have one controller working at very low density airports. But still consider that the person would need breaks etc. Furthermore, the staffing need to be higher, since that one person would still need days off, vacation etc. So you'd need maybe 3 controllers to staff a unit.... On top of that you'd need an approach setup at the centre, which technically can be done by the sector covering the area, but still it's a task someone has to do etc. etc.
Setting all this up is not just one controller cheap and easy.
Jmmoric - I understand exactly what you mean, there is a cost but the question is cost versus benefit. There comes a stage when the benefit outweighs the cost, and if a mathematical calculation does not do it for you go with your gut. I am not promoting jobs for air traffic controllers, I am responding to a perceived risk of collision at Ballina aerodrome. This is clearly recognised outside of PPrune because CASA OAR has reacted to airline concerns, as has Airservices who no doubt has had airlines ask just when they might put in a Tower.
On your other point, my explanation to pilot colleagues of Class D operations is that the Tower sequences aircraft for the available runways; this with sight and follows, creates separation in the circuit area and on the runway. It also contributes to worldwide comments about controllers "over-controlling" Class D or providing a Class C service. This is inevitable when the whole point of air traffic control is the prevention of collisions between aircraft, (See ICAO Annex 11 Para 2.2 (a)) not strict adherence to ICAO or national airspace definitions. It must, in visual conditions, sometimes be easier and safer to de-conflict two aircraft instead of just giving traffic and then having to react to unexpected pilot actions.
On your other point, my explanation to pilot colleagues of Class D operations is that the Tower sequences aircraft for the available runways; this with sight and follows, creates separation in the circuit area and on the runway. It also contributes to worldwide comments about controllers "over-controlling" Class D or providing a Class C service. This is inevitable when the whole point of air traffic control is the prevention of collisions between aircraft, (See ICAO Annex 11 Para 2.2 (a)) not strict adherence to ICAO or national airspace definitions. It must, in visual conditions, sometimes be easier and safer to de-conflict two aircraft instead of just giving traffic and then having to react to unexpected pilot actions.
It’s not a “perceived risk”. There is a risk.
The only questions (in a coherent regulatory system) are: What are the probabilities of a collision between a HCRPT aircraft and another aircraft, what would the cost be of that collision and what would be the cost of reducing that risk to (e.g.) once in a thousand years collision versus e.g. once in ten years collision, if the latter is ‘unacceptable’ and the former is ‘acceptable’. As alphacentauri has pointed out elsewhere, everyone would like zero risk, but it ain’t achievable in the real world. In the real world, the question is how many millions are you prepared to spend per percentage point reduction in risk.
The only questions (in a coherent regulatory system) are: What are the probabilities of a collision between a HCRPT aircraft and another aircraft, what would the cost be of that collision and what would be the cost of reducing that risk to (e.g.) once in a thousand years collision versus e.g. once in ten years collision, if the latter is ‘unacceptable’ and the former is ‘acceptable’. As alphacentauri has pointed out elsewhere, everyone would like zero risk, but it ain’t achievable in the real world. In the real world, the question is how many millions are you prepared to spend per percentage point reduction in risk.
Lead - While I agree with alphacentauri's argument, I worry about "paralysis by analysis". If figures such as he/she wants do exist then let us apply them to Ballina and make a decision.
In the 2017 CASA OAR supplementary study of Ballina, Paragraph 6.6 is entitled Safety Assessment. This contains two highly scientific statements:
6.6.1 Analysis of aerodrome activity at BBGA determined that the risk to airspace users in the BBGA area was highest between 0800 and1800 hrs which primarily covers daylight hours.
6.6.2 The likelihood of a safety incident between two aircraft after 1800 hrs was assessed as extremely low because all passenger transport movements are separated by time in their flight schedules and there are very few airspace users around BBGA after 1800 hrs.
In 6.6.1 CASA uses the words "determined" and "was highest" and in 6.6.2 "likelihood" and "assessed as extremely low". There is no evidence attached as to how OAR reached these conclusions, normally I would expect a hazard analysis and scoring based on a qualitative assessment matrix ranging from extreme to acceptable. If this is the standard that is acceptable to CASA when making decisions about the operating hours of a facility they believe will improve air safety then alphacentauri's suggestions are impossible in Australia. CASA further states that the airspace is "fit for purpose" (by the way CA/GRS is not airspace) so clearly they do not believe Class D airspace would be cost-effective. They are willing to wait for something - but what that something is we do not know.
My guess is that they are waiting for Airservices to say they are willing to open a Tower, and then CASA will write a report saying they should. In my view, as currently managed and operated, OAR is a waste of space.
In the 2017 CASA OAR supplementary study of Ballina, Paragraph 6.6 is entitled Safety Assessment. This contains two highly scientific statements:
6.6.1 Analysis of aerodrome activity at BBGA determined that the risk to airspace users in the BBGA area was highest between 0800 and1800 hrs which primarily covers daylight hours.
6.6.2 The likelihood of a safety incident between two aircraft after 1800 hrs was assessed as extremely low because all passenger transport movements are separated by time in their flight schedules and there are very few airspace users around BBGA after 1800 hrs.
In 6.6.1 CASA uses the words "determined" and "was highest" and in 6.6.2 "likelihood" and "assessed as extremely low". There is no evidence attached as to how OAR reached these conclusions, normally I would expect a hazard analysis and scoring based on a qualitative assessment matrix ranging from extreme to acceptable. If this is the standard that is acceptable to CASA when making decisions about the operating hours of a facility they believe will improve air safety then alphacentauri's suggestions are impossible in Australia. CASA further states that the airspace is "fit for purpose" (by the way CA/GRS is not airspace) so clearly they do not believe Class D airspace would be cost-effective. They are willing to wait for something - but what that something is we do not know.
My guess is that they are waiting for Airservices to say they are willing to open a Tower, and then CASA will write a report saying they should. In my view, as currently managed and operated, OAR is a waste of space.
To what probability/ies does ‘extremely low’ correspond? It’s a typical term that can be interpreted in different ways by different people.
But it ain’t zero (of course).
And what is the descriptor for the level at which OAR would ‘upgrade’ the airspace?
But it ain’t zero (of course).
And what is the descriptor for the level at which OAR would ‘upgrade’ the airspace?
Geoff, interesting you say that (paralysis by analysis). Id argue that is exactly what we have now. OAR are paralysed because they don’t actually have the skills or knowledge to make a determination of the best way forward. It’s not entirely their fault, because their management structure also won’t back them if they make a controversial decision.
So we end up with solutions looking for problems in the hope that the airspace it is applied to remains "fit for purpose" , then they can report that they have "done something"
Take the latest solution iteration for Ballina....the broadcast zone is to be 15nm. It makes the situation worse!! How long do we sit back and let the OAR wave the magic wand? Do we need to wait for them to kill someone? Or is that going to be ok because the latest airspace arse pluck (err I mean "risk assessment") declared it to be "fit for purpose"
Why dont we develop the tools to help the OAR do their job? Or get rid of the OAR......
Alpha
Oh and plus everything Lead Balloon posted
So we end up with solutions looking for problems in the hope that the airspace it is applied to remains "fit for purpose" , then they can report that they have "done something"
Take the latest solution iteration for Ballina....the broadcast zone is to be 15nm. It makes the situation worse!! How long do we sit back and let the OAR wave the magic wand? Do we need to wait for them to kill someone? Or is that going to be ok because the latest airspace arse pluck (err I mean "risk assessment") declared it to be "fit for purpose"
Why dont we develop the tools to help the OAR do their job? Or get rid of the OAR......
Alpha
Oh and plus everything Lead Balloon posted
Where’s Vag277 when we need him/her?
Calling Vag277.
Calling Vag277.
Invest in a portable Tower and operate a Class D. For Ballina to safely cope with additional traffic then extra infrastructure is required - additional taxiways for starters.
1. If the CA/GRO knows the tracks of both aircraft then he/she knows they will intersect, regardless of the directed broadcast from the Jab, so they are mutual traffic. That is why the aerodromes share a CTAF.
Alphacentauri - a nice point and you are quite correct, although I might say that IMO the OAR has paralysis and a lack of analysis! The last review I could find was the 2017 supplementary I referred to above, yet the Minister states that they will respond quickly to any new issues that arise! I think we are in wild agreement, although I believe the evidence is in, we do not need any more analysis.
TIEW - I fail to follow your logic in terms of sharing a CA/GRS.
Sure Ballina Shire Council "volunteered" to install the CA/GRS but it operates on the common CTAF so it cannot ignore any communications on that frequency. I could understand the CA/GRO not getting involved with traffic advertising it is in or near LIS because he/she does not have the full picture. (For instance he/she cannot hear aircraft taxiing at LIS) There is still however a duty of care, If the CA/GRO thinks he/she has information that the pilot(s) should know he/she cannot withhold it due to a perception that it is not their business.
In this case though, one of the aircraft was heading for BNA on a track known to the CA/GRO and one was east of LIS heading for EVD. A simple chinagraph line on a map will indicate that the tracks will cross. The idea that traffic is not passed because one aircraft was broadcasting to LIS traffic instead of BNA traffic, has me foxed, I do not follow your logic.
TIEW - I fail to follow your logic in terms of sharing a CA/GRS.
Sure Ballina Shire Council "volunteered" to install the CA/GRS but it operates on the common CTAF so it cannot ignore any communications on that frequency. I could understand the CA/GRO not getting involved with traffic advertising it is in or near LIS because he/she does not have the full picture. (For instance he/she cannot hear aircraft taxiing at LIS) There is still however a duty of care, If the CA/GRO thinks he/she has information that the pilot(s) should know he/she cannot withhold it due to a perception that it is not their business.
In this case though, one of the aircraft was heading for BNA on a track known to the CA/GRO and one was east of LIS heading for EVD. A simple chinagraph line on a map will indicate that the tracks will cross. The idea that traffic is not passed because one aircraft was broadcasting to LIS traffic instead of BNA traffic, has me foxed, I do not follow your logic.
