VFR departure restrictions [Archive]

Pierre Argh

24th Jul 2007, 08:13

Would anyone care to comment on the legality of a departure restriction of 2000 ft being given to VFR departures from an airport in Class G airspace?
Although there is no legal requirement to maintain 2000' once VFR and clear of the ATZ or any other regulated airspace, the point is would you have been allowed departure in the first place if you didn't agree to comply?
Presumably there is other traffic to affect, and it would be quite simple for the Controller to hold you on the ground until that traffic is clear. Such restriction is given in the name of expedition, try to screw ATC by quoting regulations and legality and I suggest you might find yourself having a different arguement whilst still at the holding point?
(If you are unhappy with a restricted departure clearance the Phrase "unable to comply" will suffice)

WorkingHard

24th Jul 2007, 08:42

We all at some point have our doubts about things, pilots as well as controllers but surely it is better to simply ask. I prefer to comply if possible and ask privately after the event. Still may not agree with what I am told but then in the comfort of a telephone call it can be discussed and reasons explained from both sides.

silverknapper

24th Jul 2007, 10:39

Not sure if the original poster was present at the very helpful meeting hosted at the aero club by ATC a few months ago. At it, the controllers held a presentation followed by an individual Q&A session. I found it very helpful. The controllers were at pains to stress that this is not obligatory - BUT if you are unable to comply no problem. your release MAY take longer due to IFR inbounds.
I would be interested to know what your concerns are Single Spey. if you are going en route and terrain clearance is an issue then surely a few minutes at the holding point will be no problem for your safety.
There is, as everywhere, the small minded majority who try to be awkward for the sake of it. "we're in class G" etc etc. Interestingly usually the ones who fly bi monthly. I personally would consider that compliance where possible, and mutual understanding with the controllers would be far preferable to trying to make a point. It is for a reason that this 'restriction' is necessary. If everyone flying VFR were to take a negative attitude to it it may well result in incidents which would lead to further 'restrictions' and perhaps the accelerated introduction of Class D airspace to the highlands.

Any thoughts?

Single Spey

24th Jul 2007, 17:39

silverknapper

All responses acknowledge the authority of ATC within the ATZ BUT

if you are unable to comply no problem. your release MAY take longer due to IFR inbounds.

Why should my departure be delayed by an IFR inbound in Class G airspace? ATC are not there to provide separation. They should pass the traffic information to me and then let me decide on acheiving separation.

There is, as everywhere, the small minded majority who try to be awkward for the sake of it. "we're in class G" etc etc. Interestingly usually the ones who fly bi monthly.

You know nothing about my background in aviation nor how often I fly, nor in what types of aircraft.

I personally would consider that compliance where possible

That is your decision - if you wish to allow ATC to provide you with separation where they have no remit to do so. Perhaps you are also happy to comply with them telling you when to turn onto base leg in the circuit, or when to switch on the pitot heater or, in extremis, when to 'just turn left now' whilst you are etablished at 300 ft on final approach. Personally when operating in airspace where it is MY decision I prefer ATC to pass me the information in accordance with procedures laid down in the Air Navigation Order and then I can make my own decision.

If everyone flying VFR were to take a negative attitude to it it may well result in incidents which would lead to further 'restrictions' and perhaps the accelerated introduction of Class D airspace to the highlands.

You have already effectively conceded the airspace if you accept that ATC are providing separation, but you have not put in place the underlying mechanisms to ensure that everyone knows what the situation is.

What happens if I follow the 2000 ft restriction but then have an AIRPROX with a non-squawking aircraft in the vicinity that is not talking to the ATC unit? Who is responsible? Because I have accepted delegation of my separation to ATC even though I am VFR, am I absolved of any responsibility?

ATSOCAS are defined so that, by and large, all participants understand their responsiobilities. ATSInsideCAS are similarly well defined. I do not believe that individual units should take it upon themselves to mandate changes (ie you may be delayed because of an IFR inbound inside our radar cover unless you accept an altitude restriction) to these procedures.

Finally you seem to see the introduction of Class D airspace as inevitable viz the accelerated introduction of Class D. Why?

Pierre Argh

Presumably there is other traffic to affect, and it would be quite simple for the Controller to hold you on the ground until that traffic is clear. Such restriction is given in the name of expedition, try to screw ATC by quoting regulations and legality and I suggest you might find yourself having a different arguement whilst still at the holding point?

If the conflict would occur outside CAS then the controller should inform me about the traffic and not restrict my flight as it is not his responsibility to provide separation. If he wishes to hold me for this reason is he willing to pay for the additional cost of my flight? To paraphrase your coment, may I suggest that if ATC try to screw pilots by acting outside their remit they might find themselves having a discussion with CAA SRG.;)

Roffa

24th Jul 2007, 18:16

Single Spey, you do seem to have a bit of an anti-ATC bias for some reason. I'd be curious to know why?

Anyway, here's what the good book says...

Approach Control

Outside Controlled Airspace

1.4.1 An air traffic control unit at an aerodrome outside controlled airspace (Class F and G airspace) shall provide approach control services to aircraft, as determined by the aerodrome operator and approved by the CAA, from the time and place at which:

a) arriving aircraft place themselves under the control of approach control until control is transferred to aerodrome control;

b) departing aircraft are taken over from aerodrome control until they no longer wish to receive a service or are 10 minutes flying time away from the aerodrome, whichever is the sooner;

c) overflying aircraft place themselves under the control of approach control until they are clear of the approach pattern and either no longer wish to receive a service or are 10 minutes flying time away from the aerodrome, whichever is the sooner.

1.4.2 Aircraft within an aerodrome traffic zone are required to comply with instructions from the air traffic control unit. Flight in Class F and G airspace outside the zone is permitted without an air traffic control clearance. However, controllers may assume that pilots of aircraft flying in the vicinity of the aerodrome in RTF contact with the air traffic control unit are complying with instructions unless they state otherwise. Controllers are to provide an air traffic control service accordingly.

You can work with the system, or against it. The choice is yours...

Single Spey

24th Jul 2007, 19:19

Roffa

Not biased at all against ATC. However I am against ATC making decisions which are outside their remit and which pilots do not realise they have the option to disregard. I am aware of many occasions when ATC have instructed pilots to manoeuvre when they should be passing traffic info and letting the pilot decide on the separation/manoeuvre to be applied. Controllers on the whole do a wonderful job but there are a growing number who seem to believe that posession of a little yellow book gives them authority which in reality they do not have. Unfortunately a proportion of users of Class G airspace are not aware of this and do not have the knowledge to challenge these instructions. As a result I believe that they are becoming less capable as pilots. Being Pilot in Command relies to a very large degree on assimilating information and making decisions. This skill is not being developed where the decision making process is devolved to other agencies when it should not be.

Single Spey

24th Jul 2007, 19:38

Roffa

The good book also says:

3 Control of VFR Flights

3.1 Although in Class D, E, F and G airspace separation standards are not applied, ATC has a responsibility to prevent collisions between known flights and to maintain a safe, orderly and expeditious flow of traffic. This objective is met by passing sufficient traffic information and instructions to assist pilots to see and avoid each other.

I do not consider having an SOP departure altitude restriction to be passing sufficient traffic information. Fair enough for each departure to pass specific traffic info with the necesary instruction - again this allows the pilot to decide in conjunction with ATC.

Riverboat

24th Jul 2007, 22:14

Single Spey, I fully agree with your post. No disrespect at all to ATC - fine bunch of people, mostly - but it is important that the balance is kept.

Everything you have written makes sense. (Unlike Silverknapper, which is complete rubbish.)

bookworm

25th Jul 2007, 07:58

Under a RAS in class G airspace from a controllers point of view, the fact that you are VFR is of little difference if say the commercial aircraft gets a TCAS climb. They have then failed to provide a RAS and the paperwork involved from the pilot and controller when a TCAS climb is initiated just causes more headaches.

So in order to avoid your headache, you're passing the problem to Single Spey.

It's not the role of ATC in class G to ensure that TCAS equipped aircraft avoid RAs. It's similarly impossible to guarantee standard separation from other aircraft in class G, and the loss of standard separation under a RAS is not a "failure to provide" the RAS. Such a guarantee is not possible in the absence of an air traffic control service.

If your airport wants to provide greater protection for commercial users of that airport than is provided for in class G airspace, there is a well defined procedure for an application for controlled airspace which means that due process ensures the cost-benefit for all airspace users is considered.

Pierre Argh

25th Jul 2007, 08:21

SS - whilst not disputing the facts of your response to my post, it is a fact that ATC have to provide separation (as you agree). This remit is achieved, as far as you are concerned, by ATC giving you traffic information; but any IFR Traffic is entitled to separation and acheiving this may require repositioning, which has to be done before they can allow you to depart into confliction. If there are multiple IFR tracks, of course, this may take time and is probably going to be unexpeditious for all concerned (?) - so the simple answer for the Controller is to seek your compliance.

Regarding the point you make about conflictions you might encounter - an ATC service is available to VFR as well (as you undoubtedly know) - if the airfield is busy (probably why the restriction is applied) then why not ask for a RIS until clear of the immediate area?

Sorry if my use of the word "screw" wound you up - it was not my intent, simply trying to say that I'm sure ATC are only trying to do their job, and help out all their users, but when busy that isn't always easy and a little cooperation, understanding and trust is always welcome.

Finally, as I believe you are talking about a Mil Airfield (?) I regret to inform you SRG have no remit to take issue in their operation - they might make representation to Air Command but I doubt, when the safety card is played as it would inevitably be, the matter would go much further? (Incidently, presumably you have elected to fly into said Military Base - are you aware that in doing so you agree to comply and accept Military procedures and practices?)

Pierre Argh

25th Jul 2007, 08:32

Bookworm says If your airport wants to provide greater protection for commercial users of that airport than is provided for in class G airspace, there is a well defined procedure for an application for controlled airspace which means that due process ensures the cost-benefit for all airspace users is considered. and is therefore presumably aware that in order for an application for Regulated Airspace (a more accurate term I think) there are a number of loops to jump through - one of the most significant is meeting the minimum number of passengers shifted. Close to my home, Exeter and Plymouth are both commercial airports handling significant numbers of passenger flights, with only an ATZ to protect them. It's not quite as simple as you make out?

...But that's getting away from SS's point

Kiltie

25th Jul 2007, 09:02

Why are you trying to be coy about the fact that it is INVERNESS that have introduced this system SingleSpey?

I have never been passed a VFR altitude restrictive CLEARANCE nor INSTRUCTION by Inverness ATC. They phrase it as a REQUEST to which I am usually able to happily comply. You (quite innocently I expect) state that ATC are providing you with SEPARATION. This is not the case. INV ATC are merely trying to reduce the likelihood of passing avoiding action to IFR flights.

Roll on Class D as Silverknapper implies. I have had too many instances emerging out of IMC on the approach to have a VFR aircraft pass too close for comfort. VFR transit through Class D, in particular to the draft design I have seen for Inverness, is no great hardship.

From your rebuke it would seem you have taken Silverknapper's remarks personally Singlespey. Perhaps if you chose to tell us in what capacity you use INV we may be able to convince you to be somewhat more open minded. Personally I have operated in and out of INV for 18 years in commercial turboprops, jets and private aircraft, twice last week IFR and the day before yesterday VFR.

Riverboat - I have read silverknapper's post over and over again and I can't work out why you consider it "complete rubbish." It may not be an exhaustive explanation but it certainly seems sensible.

Playing the game with local ATC cuts good favour in the long run; waving the rule book around is best left to stand off when all else fails.

bookworm

25th Jul 2007, 10:15

and is therefore presumably aware that in order for an application for Regulated Airspace (a more accurate term I think) there are a number of loops to jump through - one of the most significant is meeting the minimum number of passengers shifted.

But who's in the better position to understand the overall cost-benefit of mandating air traffic control services to particular classes of user: the Directorate of Airspace Policy, or an individual ATCO? I think the name gives it away. ;)

bookworm

25th Jul 2007, 10:37

earthey

I appreciate your measured response to my rather provocative post.

Regardless of he rules, it is worth remembering that these are still lumps of metal full of people, and it is taking a big gamble to simply hope some of the VFR aircraft "see" the conflict.

But that's not your gamble. That's a gamble that is shared in responsibility between DAP, SRG, the airline and the crews involved. And the problem with imposing your solution on your view of the risk management picture, is that your view of that picture is often incomplete, particularly in class G airspace. As SS says:

What happens if I follow the 2000 ft restriction but then have an AIRPROX with a non-squawking aircraft in the vicinity that is not talking to the ATC unit? Who is responsible? Because I have accepted delegation of my separation to ATC even though I am VFR, am I absolved of any responsibility?

That is the essence of the issue. If someone has responsibility for risk management, they also have to have appropriate power to control the risk (and not just the risk that you can see, the whole risk picture). If you allow ATC to give instructions to and place restrictions on aircraft outside controlled airspace, you take the necessary control away from the pilot, despite the pilot still having the responsibility.

DFC

25th Jul 2007, 11:09

Single Spey,

You need to understand what a pile of crap RAS can be if there is other traffic about. Here is an example which demonstrates what I mean;

ABC123 a commercial pax flight in inbound from the south in IMC descending and receiving a RAS from a nearby military airfield. About 8nm from the overhead, ATC say "ABC123 avoiding action turn right heading 090 unknown traffic left to right 12 o'clock 7 miles.

After several avoiding action turns, and now getting further from the destination, the pilot questions ATC regarding the unknown and ATC respond that; they are probably in the circuit at the destination but to get any closer we would have to cancel RAS (against company policy when IMC in UK Class G).

With that kind of service, you can see why commercial companies put such pressure on aerodrome authorities (and thus ATC) to ensure that such stupid reasons for delay do not happen.

I can see your point and I agree totally that Class G should not be operated as Class C. However, simply when flying in the UK think of it as Class C without the known traffic environment!

Personally, I am far more worried about the pilot who departs VFR and then enters cloud just outside the ATZ cause they have an IMC rating and want to get on top.

The whole problem is that for many reasons there is no trust between sections of the team.

Perhaps in this case, it would have been better for ATC to simply provide traffic information and advice as per MATS 1- B737 inbound from...descending to 3000ft not above 2000ft until clear of that traffic Report the traffic in sight.

Regards,

DFC

Pera

25th Jul 2007, 11:19

ATC have an inbuilt pucker factor when it comes to aircraft getting too close together. Regardless of the strict application of the rules they will apply separation or segregation when necessary. The rules often don't keep up with the changing traffic dynamics.
I hope that all ATC documents state something like this.
"Nothing in this part precludes a controller from using discretion and
initiative in any particular circumstance where these procedures appear to be in conflict with the requirement to promote the safe conduct of flight."
Safety is the primary concern.

ShyTorque

25th Jul 2007, 12:48

If you allow ATC to give instructions to and place restrictions on aircraft outside controlled airspace...

Then it is no longer "outside controlled airspace". ATC cannot, by definition do so. They can try, but a pilot is under no obligation to comply in those circumstances.

reportyourlevel

25th Jul 2007, 13:19

I hope that all ATC documents state something like this.
"Nothing in this part precludes a controller from using discretion and
initiative in any particular circumstance where these procedures appear to be in conflict with the requirement to promote the safe conduct of flight."
Safety is the primary concern.

The UK MATS Part 1 Certainly does:

Nothing in this manual prevents controllers from using their own discretion and initiative in any particular circumstance.

This is an interesting debate. Even though this is class G, so no standard separation is applied, the fundamental purpose of an ATC service is to prevent collisions between aircraft in the air. By applying the height stop, the ATCO is fulfilling this responsibility. I would expect that when you are no longer in conflict they will remove the restriction.

ryl

Chilli Monster

25th Jul 2007, 13:28

It's quite simple:

TCAS RA - ATCO has failed

No TCAS RA - ATCO has succeded

So you get requested to restrict climb for a short while to achieve the above - where's the problem? My licence, My livelihood, My ar$e I'm going to cover (which ultimately might be yours too).

I don't have an intimate understanding of Inverness, but they're doing something which we do (Mixed GA / Commercial operation in class 'D') which keeps the traffic moving with minimal co-ordination.

If you want to blame somebody - blame the person who insisted TCAS RA's have to be adhered to even if you can see the traffic involved (but that's not going to happen - is it?)

bigelz1215

25th Jul 2007, 15:07

sorry but I am just a dumb ppl - but as far as I am concerned , i consider ATCO's to be professional enough to keep me away from becoming a major contributor to an aluminium rainshower , legal or not if they request below 2000' i'm sure not going to argue unless I can see cumulus granitus or some other obstruction in the way :) when I would politely suggest i might initiate a climb. i cannot see the reason people are complaining , c'mon people we are all trying to fly safely in an area which is becoming busier with commercial traffic, anything that keeps all pilots and pax safe is ok by me :ok:

Dont tell um pike

25th Jul 2007, 15:31

Did this restriction delay your flight at all ? No
Did this restriction delay the inbound at all ? No
Was safety compromised ? No

Sounds completely reasonable to me. safe , orderly and expeditious :D
DTUP

bookworm

25th Jul 2007, 15:33

i consider ATCO's to be professional enough to keep me away from becoming a major contributor to an aluminium rainshower , legal or not if they request below 2000' i'm sure not going to argue unless I can see cumulus granitus or some other obstruction in the way when I would politely suggest i might initiate a climb.

And 99% of the time, that's the way it's going to work.

It's the 1% of cases where the ATCO "refuses" your "request" and you're heading towards that gaggle of 6 (or was that 7?) gliders just beneath the cu, when we need to be clear who's responsible for what. Or perhaps that 1% where the delay in your VFR departure caused by enforced separation from the IFR inbound (which you saw at 10 miles) takes you rather closer on the climbout to the CB that's approaching the airfield?

In all cases, the ATCO is, no doubt, trying to be professional and reduce what he or she can see as risk. But sometimes it's only one piece of the picture, and a vital piece is missing.

bookworm

25th Jul 2007, 15:38

TCAS RA - ATCO has failed

How can this possibly be a "failure" when the ATCO is not responsible for, and has no way of guaranteeing, separation?

BEXIL160

25th Jul 2007, 15:53

Interesting thread, viewed by me both as an ATCO and sometime private pilot.....

Ahem, well, I fly from a very pleasant airfield near Salsibury plain, very adjacent to a BIG Army Air Corp base (the biggest grass airfield in the Uk I'm told) and a large R and D airfield with lots of noisy fast pointy things flying into /out of it.

All THREE airfields (four if you count Salisbury Intl) are in CLASS G airspace, not withstanding the MATZs (which presumably Mr. Spey doesn't recognise anyway, because in the Civil world it counts for 'nowt :rolleyes:)

Anyway, my point is : we all rub along together quite nicely thank you, with PROCEDURES in Class G (including ALT restrictions) which let everyone, by and large, get on with what they want to do. In relative SAFETY.

Yes we're all in class G, and therefore outside the 4 ATZ's there's no actual compunction to follow the various procedures but...... you'd look a bit silly if you didn't follow them and had a close encounter of the fast jet / helicopter / C130 / VC10 etc etc kind.

I don't think the explanation that "I was VFR and exercising my rights in Class G" would cut much ice at the subsequent board of enquiry (or inquest :( ) Any barrister would have a field day.

The phrase "Duty of Care" doesn't only apply to controllers, pilots should be aware of the implications also.

Never met an ATCO that delayed traffic (IFR or VFR) for anything other than SAFETY reasons. Percieved or actual. Doesn't matter. They have YOUR safety at heart.

Back to gazing at the low stratus.......

rgds BEX

Vino Collapso

25th Jul 2007, 15:56

I hope the postings from some of the flying fraternity on this forum do not represent the opinions of the flyers who are not lurkers and posters. If they do then we are all doomed.:eek:

The worn out old cry of 'I know my rights' will only serve to marginalise GA even further than it is now.

Chilli Monster

25th Jul 2007, 15:57

How can this possibly be a "failure" when the ATCO is not responsible for, and has no way of guaranteeing, separation?
Because you do the best you can, with the tools and methods available, without relying on the safety net.

It may not be a failure in your eyes - Professionalism means the individual regards things differently, especially if you could have prevented it.

bratbaak

25th Jul 2007, 16:18

Single Spey when providing a RAS controllers have to attempt to achieve 5 miles or 3000 ft separation between non-participating aircraft, the moment you do not accept a request for not above 2000ft you become non-participating and hence a problem. As already asked why do you need to refuse this unless for terrain or awkwardness. As you argued about ATCO instructions on a previous thread how would you feel if a first cross country solo was allowed to depart up to any level and ended up in an airprox or worse, when a simple not above 2000ft would have kept everyone safe and moving. You queried how this request constitutes traffic info it doesn't because if one is not above 2000ft and the other at 3000ft they are not traffic. As stated before everyone avoids each other, everyone keeps moving towards where they want to be, what exactly is your problem with this? As for the, well what if I have an airprox with someone below 2000ft question, this negates your stance of we are all capable of seeing and avoiding so just let us get on with it and if you have seen it and the only way to avoid is to climb then either ask, if time, or act and tell us why, believe it or not we are trying to avoid collisions happening as much as you.

055166k

25th Jul 2007, 16:23

A question for clarity if I may?
Once outside the ATZ do you leave the frequency or do you still expect to receive some kind of service? What service..if any...would that be, and how do you interpret your responsibilities to other airspace users?
A scenario might be that the approach controller will issue a descent clearance which takes into account all known and relevant traffic that is complying with a "not above" restriction. Perhaps the controller's worload in such case may remove the need to transmit a string of traffic information on VFR traffic which does not wish NOR IS REQUIRED to comply in the type of airspace you describe. Can you guarantee in all circumstances that you would spot IFR traffic descending through cloud with sufficient time to avoid, particularly from behind and above?

silverknapper

25th Jul 2007, 21:24

SS
Having read through some of your previous posts, I can only come to the same conclusion as Roffa - you seem to have a real chip on your shoulder with regards to ATC. Quotes like but there are a growing number who seem to believe that posession of a little yellow book gives them authority which in reality they do not have only serve to support this.
Whilst most of what you post is technically correct, it is your a lack of what I can only describe as situational empathy coupled with a lack of airmanship that quite frankly worries me.
At this meeting I mentioned previously ( which I'm sure would be beneficial to us to know if you attended so that we know exactly how much you know about the situation, and indeed if you are a pro active member of the GA community who is voicing a general opinion) ATC were at pains to stress that their sole priority is to shift traffic in a SAFE and expeditious manner. They are not trying to inconvenience anyone, but enhance safety. If you were at the meeting perhaps you should have voiced your concerns there. It was part of an open consultation process, and if there were reasoned objections at the time perhaps there would be alterations to the original plan.
Remember this 'restriction' is a REQUEST. If you don't wish to comply then tell them. Technically you are well within your rights, if somewhat devoid of an ability to think of the bigger picture.
Since the introduction I have made countless VFR and IFR flights, public transport and GA, from INV and not once have I heard this request being made. If everyone cooperates then goodwill will prevail
Your argument about Airprox is a poor one. there have been many incidents in the past, VFR vs VFR, IFR vs IFR and IFR vs VFR. Hence the introduction of both radar and this procedure, to improve SAFETY. With the best will in the world not every PPL is on the ball with a sharp scan and good situational awareness. As Kiltie correctly points out ATC are NOT providing separation, but trying to avoid conflictions. If you are at not above 2000' VFR and cannot manage to see and avoid then perhaps you should have stayed on the ground that day.
With the current concerns over GA's future at INV I would think that working in harmony would be the best possible way to secure the future of GA at INV. Although with people with your attitude about bring on Class D.
I look forward to you enlightening us as to your flying activities. Perhaps it would let us understand your position better.

agent007

25th Jul 2007, 22:10

Well said Silver the meeting was most informative and well received by all that were there that night. The procedures seem to be working well when the radar is working, and if you are willing to accept the not above 2000feet there seems to be seldom any delay. It is as stated a request an not an instruction which is soon lifted by the radar controlers ASAP.

flower

25th Jul 2007, 22:16

It is ironic that a procedure brought in to facilitate the movement of GA and not hold them on the ground is picked upon by some as a problem. Many airports use similar procedures to allow a free flow of VFR traffic out of and into zones.

PPRuNe Radar

26th Jul 2007, 09:12

TCAS RA - ATCO has failed

Not necessarily. The ATCO 'clears' 2 aircraft to levels which are 'separated'. Both pilots comply but TCAS predicts that they will come close (due to closure rates, or inappropriate rates of climb or descent) and issues an RA. And the ATCO has failed ?????? :ooh:

Chilli Monster

26th Jul 2007, 10:08

There will always be the RA's caused by traffic closure speeds - you'll never get around them. However, they are in the minority and so I feel my original statement probably holds for 90% of RA's.

The "defensive" controlling exercised by Inverness is a way to cut this down.

Having said that - I've seen an RA where a VFR had the IFR in sight, the IFR had the VFR in sight, the VFR was going to pass behind and below and STILL the IFR had to go-around due to the RA generated.

Nobody had failed there, and nobody had done anything wrong - but policy is still an RA must be followed - so reducing the RA possibility has to be the way to go in these types of circumstances.

DFC

26th Jul 2007, 11:27

Chilli,

The RA has to be followed because the traffic you see may not be the one that is generating the RA and it is unsafe to delay the reaction while trying to figure out exactly what is happening.

Regards,

DFC

Chilli Monster

26th Jul 2007, 11:39

The RA has to be followed because the traffic you see may not be the one that is generating the RA and it is unsafe to delay the reaction while trying to figure out exactly what is happening.

Which was exactly the situation which caused the San Diego mid air, which was one of the main drivers behind TCAS / ACAS.

bookworm

27th Jul 2007, 10:42

Mixed in with this basic philosophy are a whole list of other ingredients, including the rules of RAS, flight priorities, "Duty of care", and heaven forbid, the application of our own common sense! It is, I guess the duty of care principle where we could leave ourselves open to attack.

earthey

I imagine my posts have come across as unsympathetic to the ATCO who simply wants to "do the right thing" -- I'm not. In the same way that you're making the point that "it's not as simple as that", I'm making a similar point that because the ATCO only has a limited part of the risk-management picture, "doing the right thing" by issuing instructions in class G has the potential of making things less safe, and that for the pilot it isn't simply about the freedom to do what he wants, but also about the ability to manage his risk. I have no doubt, for example, that as discussed in this thread (http://www.pprune.org/forums/showthread.php?t=283976) ATC at Southend issued instructions in what was perceived as the best interests of safety, with tragic results.

The "ATC duty of care" interpretation that is now pervasive is one of the worst things that has happened to aviation safety in recent years. The blurring of responsibility for risk management between pilot and ATC seems to have done nothing for safety and has just raised stress levels.