Protecting Missed Approach in NZ
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Protecting Missed Approach in NZ
Very confusing system in NZ; 
AIP and Jepps state that the controller may protect the missed approach by requiring an aircraft to join the circuit visually in the event of a missed approach off an instrument approach.
When you are cleared for an instrument approach, you are also cleared for the (instrument) missed approach, therefore my take on this is you set the instrument missed approach alt ie usually 3000'. The controller MAY change this to a clearance to join the circuit visually (as long as 8k vis and 2000' clg).
A common perception is that you should set circuit altitude as the missed approach altitude off an instrument approach when the wx is better than 8k vis and 2000' clg. I think this is wrong.
Like to hear some other opinions.
AIP and Jepps state that the controller may protect the missed approach by requiring an aircraft to join the circuit visually in the event of a missed approach off an instrument approach.
When you are cleared for an instrument approach, you are also cleared for the (instrument) missed approach, therefore my take on this is you set the instrument missed approach alt ie usually 3000'. The controller MAY change this to a clearance to join the circuit visually (as long as 8k vis and 2000' clg).
A common perception is that you should set circuit altitude as the missed approach altitude off an instrument approach when the wx is better than 8k vis and 2000' clg. I think this is wrong.
Like to hear some other opinions.
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It is a bit confusing, but it significantly reduces delays when conditions are suitable - it means ATC can launch a departure with an aircraft on short final which saves a significant amount of time. You will notice the delays caused by non-circling aircraft particularly at WLG.
If conditions are above the limit, you are required to join the circuit, so it would make sense to set circuit alt on final, rather than have to quickly change it after a go-around
In practice, if you have to go-around due to runway sep etc joining the circuit gets you on the ground a lot sooner so surely that's a good thing. If you're going around due to weather conditions, it will always be the standard MA anyway.
If conditions are above the limit, you are required to join the circuit, so it would make sense to set circuit alt on final, rather than have to quickly change it after a go-around
In practice, if you have to go-around due to runway sep etc joining the circuit gets you on the ground a lot sooner so surely that's a good thing. If you're going around due to weather conditions, it will always be the standard MA anyway.
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But you are not cleared to join the circuit at that point, seems like its anticipating a clearance which we shouldn't do in aviation??. eg if the transmissions are blocked which is a reasonably realistic scenario...would you join the circuit off an ILS without a clearance. I think its more prudent to follow the clearance that we have at that time which is climb straight ahead to 3000'.
Agree protecting the missed approach has to be done in NZ, just too grey an area..
Agree protecting the missed approach has to be done in NZ, just too grey an area..
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If ATC want this, they will ask you (at about the time they expect to to come visual) something like "in the event of a missed approach, would you accept a visual circuit?" If, after assessing condx in the circuit area, you agree, they will then respond with that as a requirement.
Plan for and set your alerter to the published MAP altitude until you are cleared for something else.
If you dont agree, the standard MAP will always be available. Contollers especially in WLG use it a bit.
It is your choice, and it was quite simple I thought. Thats how I understand it anyway.
Tarq57 or someone may be able to elaborate further?
Plan for and set your alerter to the published MAP altitude until you are cleared for something else.
If you dont agree, the standard MAP will always be available. Contollers especially in WLG use it a bit.
It is your choice, and it was quite simple I thought. Thats how I understand it anyway.
Tarq57 or someone may be able to elaborate further?
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Actually, on closer inspection I think you're right.
So you would prepair for a standard missed approach unless cleared otherwise, and should set the MCP accordingly
ATC may protect the missed approach by requiring arriving aircraft to circle visually within the aerodrome circuit
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Hmmm, its a really good point. In our company, provided the weather is suitable via the company sops and we haven't advised we are unable to do a harbour circuit, we breif for the harbour circuit unless told to carry out a full missed approach. We still set 3000' however until we are in the go around where we re-set 1500'. As far as I'm aware, we just continue into the circuit 1500' without clearance as it's expected. Have to clarify that one? Good point to bring up with training.
Another confusing ATC instruction is "no speed" on an approach to 16 via Libri. It doesn't actually mean we can fly faster than 170kt at Libri. I always thought that when they referred to "no speed" it meant the full speed restriction on the star? apparently we must get that clearance from the tower to be faster than 170 at Libri. You would think they could liase with one another and make it a little clearer.
Another confusing ATC instruction is "no speed" on an approach to 16 via Libri. It doesn't actually mean we can fly faster than 170kt at Libri. I always thought that when they referred to "no speed" it meant the full speed restriction on the star? apparently we must get that clearance from the tower to be faster than 170 at Libri. You would think they could liase with one another and make it a little clearer.
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Fruet
What category aeroplane are you flying?
From a very distant hazy memory the rules for cat a/b are possibly different to cat c regarding the MAP issue?
What category aeroplane are you flying?
From a very distant hazy memory the rules for cat a/b are possibly different to cat c regarding the MAP issue?
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Actually Warren9, its not that simple. Firstly, you have to tell both approach and tower that you will not be able to accept visual circuit in the event of the missed, so as you say; the "published missed approach is always available", is not correct. You have to accept the circuit if you have not told both these controllers you will not accept it.
Also, I have not heard controllers state the phrase "in the event of a missed app, will you accept the visual circuit?", in the last 12 months. I presume it has been removed from their manual.
I agree with you philosophy on MAP alt in MCP.
Our SOPs state to set the circuit alt for MAP alt if wx conditions suitable.
So seems not so cut and dried as I would have thought.
Also, I have not heard controllers state the phrase "in the event of a missed app, will you accept the visual circuit?", in the last 12 months. I presume it has been removed from their manual.
I agree with you philosophy on MAP alt in MCP.
Our SOPs state to set the circuit alt for MAP alt if wx conditions suitable.
So seems not so cut and dried as I would have thought.
There is a bit of confusion about this, and pretty much always has been.
The confusion seems to have increased in more recent times, with some operators not able to circle under any circumstances, the published minimum in the chart being lower than the accepted industry standard minimum for cat C (at least in Wellington) (1500/8km vs 2000/8km) and the often subjective area of "how much turbulence and windshear exists, and is it likely to make the circuit unacceptable"?
Basically the AIP states that any time a crew cannot accept a circuit, approach control should be informed of that fact. (Don't have the AIP reference, sorry. 1: I'm at home, and 2: That document is counter-intuitive to navigate these days.)
Once approach has been informed, the likely result is that a 175kt speed restriction is placed on the approach, commencing at 10DME final. Reason: Tower is able to provide the protections based on tables issued for each a/c performance category. (These tables can be complicated.) Tower is unable to make a value judgement of this; the separations applied are delegated for use, and it's an approach separation. The distances used have been worked out using the simulator, and where indicated, tweaked over time and real life experience.
You should interpret the "may require an aircraft to enter the circuit.." as "That's quite likely to happen unless you've told us otherwise," and if you'd prefer the MAPP (but don't actually need it) let us know; it may be available.
It should be simple. If the weather was always clear cut, and everyone had a similar performance, and there weren't terrain issues affecting the ability to turn off the MAPP at WN, it would be. Unfortunately, reality all too frequently intrudes.
Where approach has previously advised a speed restriction and then cancels it, it simply means that Tower has no departing traffic to go ahead of the inbound. Where "no speed restriction" is advised, without previous discussion, you can fly at the barbers pole to the threshold, if you want. (The subsequent overshoot would be fun to watch, I'm sure, but you get the idea.)
As stated above, when the arriving a/c is believed to be able to enter the circuit, the required space between it and a preceding departure may be based on visual means, rather than radar (min. 3nm, which means the "gap" can be anything from 4nm to 12nm.)) which increases runway capacity significantly.
There was a recent change in the AIP concerning the ATIS. Up until recently, the ATIS included a phrase like "All aircraft category A and B advise approach on first contact if unable to enter the circuit in the event of an overshoot." Terrible.Wordy. You could die of hunger waiting for the ATIS to cycle. (Anyone dying of hunger here reading this?) Now that requirement is published in the AIP instead, and it is up to the crew to decide based on the reported wx, and up to us to try and report the wx accurately.
There can be several different reasons for speed restrictions on approach generally; the circling status is one of them, so in answer to your question re "no speed via libri", I don't know.
Do you fly a '738, perchance?
Sorry to waffle. I'm like that on the radio, too.
The confusion seems to have increased in more recent times, with some operators not able to circle under any circumstances, the published minimum in the chart being lower than the accepted industry standard minimum for cat C (at least in Wellington) (1500/8km vs 2000/8km) and the often subjective area of "how much turbulence and windshear exists, and is it likely to make the circuit unacceptable"?
Basically the AIP states that any time a crew cannot accept a circuit, approach control should be informed of that fact. (Don't have the AIP reference, sorry. 1: I'm at home, and 2: That document is counter-intuitive to navigate these days.)
Once approach has been informed, the likely result is that a 175kt speed restriction is placed on the approach, commencing at 10DME final. Reason: Tower is able to provide the protections based on tables issued for each a/c performance category. (These tables can be complicated.) Tower is unable to make a value judgement of this; the separations applied are delegated for use, and it's an approach separation. The distances used have been worked out using the simulator, and where indicated, tweaked over time and real life experience.
You should interpret the "may require an aircraft to enter the circuit.." as "That's quite likely to happen unless you've told us otherwise," and if you'd prefer the MAPP (but don't actually need it) let us know; it may be available.
It should be simple. If the weather was always clear cut, and everyone had a similar performance, and there weren't terrain issues affecting the ability to turn off the MAPP at WN, it would be. Unfortunately, reality all too frequently intrudes.
Where approach has previously advised a speed restriction and then cancels it, it simply means that Tower has no departing traffic to go ahead of the inbound. Where "no speed restriction" is advised, without previous discussion, you can fly at the barbers pole to the threshold, if you want. (The subsequent overshoot would be fun to watch, I'm sure, but you get the idea.)
As stated above, when the arriving a/c is believed to be able to enter the circuit, the required space between it and a preceding departure may be based on visual means, rather than radar (min. 3nm, which means the "gap" can be anything from 4nm to 12nm.)) which increases runway capacity significantly.
There was a recent change in the AIP concerning the ATIS. Up until recently, the ATIS included a phrase like "All aircraft category A and B advise approach on first contact if unable to enter the circuit in the event of an overshoot." Terrible.Wordy. You could die of hunger waiting for the ATIS to cycle. (Anyone dying of hunger here reading this?) Now that requirement is published in the AIP instead, and it is up to the crew to decide based on the reported wx, and up to us to try and report the wx accurately.
There can be several different reasons for speed restrictions on approach generally; the circling status is one of them, so in answer to your question re "no speed via libri", I don't know.
Do you fly a '738, perchance?
Sorry to waffle. I'm like that on the radio, too.
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It shouldnt really be a big deal as long as you brief for it..or at the very least have a plan.
Click..Click..get the automatics out (if you've got them) and do some proper aviating
I wonder what kind of separation are we talking about? is it 2.5 miles? and are we talking about differing types? i.e. A320 on a shortish final..and a ATR about to depart etc.
Click..Click..get the automatics out (if you've got them) and do some proper aviating
I wonder what kind of separation are we talking about? is it 2.5 miles? and are we talking about differing types? i.e. A320 on a shortish final..and a ATR about to depart etc.
I wonder what kind of separation are we talking about? is it 2.5 miles? and are we talking about differing types? i.e. A320 on a shortish final..and a ATR about to depart etc.
A320 (or Boeing) ahead of another jet on final, the distance is 4 miles. Slow a/c (eg C208) ahead of a jet on final, straight ahead SID, required distance is a whopping 12 miles. We are not permitted to shorten that distance.
The types that regularly operate IFR range from Caravan to A320/B737. On a day when the conditions are below circling for all, delays become substantial.
There's a tabular distance promulgated for all combinations of types/SIDS, and it's different for each runway.
The minimum radar separation is 3 miles.
The whole thing is a bit of a blunt tool, and there is, at times, a lot of wasted airspace. For example, no allowance is made for the fact that a lower performance departure might climb like a rocket. Nor for the fact that, although the speed of approach tested on the sim is 175, most a/c will be 10-30kt slower than that for the last 4 miles of the approach. Ironically, if a departure can accept a visual departure - which is surprisingly often even when below circling conditions exist for cat C - then visual separation may be applied up to the point geographical exists, or (as happens 99% of the time) the arriving a/c has landed.
Does it not actualy say to advise on first contact if unable to carry out a visual citcuit in the event of a "GO- AROUND" not a MAPP.
The 2 are completely different.
The 2 are completely different.
Thanks for pointing out that the two are completely different.
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So tarq57, if one was to commence a missed approach from an ILS in WLG and the weather is suitable for circling visually....You would expect us to carry out the ILS missed approach and climb to 3000' unless you cleared us to join the circuit visually. Is that a fair comment.
Thanks
Thanks
I suppose that's the original question.
I'm going to presuppose that when you say
you mean "if one was to go-around from..." (which might then become a MAPP or a circuit)
The answer is somewhat dependent on the situation.
1) You are still IMC; say, unstable on the approach (or config warning or other problem) and can not safely continue to VMC, then, even without your saying you have an emergency, ATC would treat it as such- at least in regard to other traffic - and pull something out of the bag of tricks to make sure you didn't collide with anything ahead while you are on the missed approach. It's unusual, it happens sometimes, we drop everything else and make it work. (It will work, because in this situation you are likely to be at least a 5nm final when you overshoot.We have time and space.)
2) You've heard the ATIS, and decided in advance you don't want any part of the circuit, and advised approach control accordingly, we expect the MAPP and have planned for it with the appropriate gap for the last departure ahead of you.
3) You are VMC, have to overshoot on short (ish) final for a more mundane reason (cabin not secure, too high/fast etc) we expect you to make the call and then respond to ATC instructions, which would often/usually be to join the circuit. This could vary depending on the traffic. And that's the bit, I think, where the problem lies.
What if you have a comms failure at (3)? (Or tower has a comms failure.I've had two in the past two days.)
I'd expect you to choose a course of action, squawk 7600 (which in theory sounds great, but in a high workload situation like this, I appreciate that it might take you a minute to do that, and either fly the circuit or the full MAPP, and be ready to respond to any TCAS warning.
Obviously in a highly fluid environment the traffic situation is changing. At Wellington it's not unusual to get a windshear. (Someone has to be the first on any one day to experience it.) Some companies have SOP's that say that you don't do a circuit in certain conditions of windshear/turbulence.
(3) would be a very weird occurrence. ATC would definitely treat it as an emergency, in regard to traffic management, and get circuit traffic (or IFR traffic ahead) out of the way ASAP. And hope you had a cell phone on board.
Sorry if that doesn't help much. I'd suggest default #1, if you haven't previously advised approach that the circuit is a no-go, is that you plan on joining the circuit. For us to get a Cessna downwind in VMC out of your way will happen very quickly, once we've realized the necessity. For the radar controller to get a preceding C208 in IMC heading for TY (worst case scenario) out of the way will take longer.Maybe quite a bit longer. There would fairly likely be a loss of separation.
I'm going to presuppose that when you say
if one was to commence a missed approach from an ILS in WLG
The answer is somewhat dependent on the situation.
1) You are still IMC; say, unstable on the approach (or config warning or other problem) and can not safely continue to VMC, then, even without your saying you have an emergency, ATC would treat it as such- at least in regard to other traffic - and pull something out of the bag of tricks to make sure you didn't collide with anything ahead while you are on the missed approach. It's unusual, it happens sometimes, we drop everything else and make it work. (It will work, because in this situation you are likely to be at least a 5nm final when you overshoot.We have time and space.)
2) You've heard the ATIS, and decided in advance you don't want any part of the circuit, and advised approach control accordingly, we expect the MAPP and have planned for it with the appropriate gap for the last departure ahead of you.
3) You are VMC, have to overshoot on short (ish) final for a more mundane reason (cabin not secure, too high/fast etc) we expect you to make the call and then respond to ATC instructions, which would often/usually be to join the circuit. This could vary depending on the traffic. And that's the bit, I think, where the problem lies.
What if you have a comms failure at (3)? (Or tower has a comms failure.I've had two in the past two days.)
I'd expect you to choose a course of action, squawk 7600 (which in theory sounds great, but in a high workload situation like this, I appreciate that it might take you a minute to do that, and either fly the circuit or the full MAPP, and be ready to respond to any TCAS warning.
Obviously in a highly fluid environment the traffic situation is changing. At Wellington it's not unusual to get a windshear. (Someone has to be the first on any one day to experience it.) Some companies have SOP's that say that you don't do a circuit in certain conditions of windshear/turbulence.
(3) would be a very weird occurrence. ATC would definitely treat it as an emergency, in regard to traffic management, and get circuit traffic (or IFR traffic ahead) out of the way ASAP. And hope you had a cell phone on board.
Sorry if that doesn't help much. I'd suggest default #1, if you haven't previously advised approach that the circuit is a no-go, is that you plan on joining the circuit. For us to get a Cessna downwind in VMC out of your way will happen very quickly, once we've realized the necessity. For the radar controller to get a preceding C208 in IMC heading for TY (worst case scenario) out of the way will take longer.Maybe quite a bit longer. There would fairly likely be a loss of separation.
You're welcome.
FWIW, wouldn't be at all surprised if one day, maybe in the not too distant future, a circuit in the event of an overshoot is a thing of the past. All departures/arrivals could end up having standard gaps. RNP and all maneuvers programmed into the FMS will be the norm. And I'll have a big dog watching me, just like you.
FWIW, wouldn't be at all surprised if one day, maybe in the not too distant future, a circuit in the event of an overshoot is a thing of the past. All departures/arrivals could end up having standard gaps. RNP and all maneuvers programmed into the FMS will be the norm. And I'll have a big dog watching me, just like you.