TCAS safe for ATC?
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Well, that's what most pilots have been trained to do, and it's what airmanship dictates. Unfortunately some obviously either forget or 'don't think it's important.' This seems to be the case here. Believe me, usually, passing the traffic info should prevent this.
It's odd that the other aircraft didn't have an RA though, if his TCAS system is switched on, the RA should be coordinated and both aircraft will get one.
It's odd that the other aircraft didn't have an RA though, if his TCAS system is switched on, the RA should be coordinated and both aircraft will get one.
Ok, to throw the bomb out there, just what is wrong with "position and hold." vrs Line up and wait???? Don't say just cause that is ICAO. That doesn't hold water with me. ICAO makes changes, just like that stupid one not so long about on changing to taxi to holding position.... Looks to me like they CAUSED more of a problem.
If everyone were to use the consistent phraseology of "line-up and wait", then the phraseology "taxi to holding position" wouldn't have been a problem. It's only because a significant proportion of the world chooses to use the non-ICAO "position and hold" that "taxi to holdin position" has a potential ambiguity to that subset of pilots. AFAIK, no one died uncovering the ambiguity.
Ohcirrej
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Quick question for the drivers out there.
As we often run visual approaches here in the frozen north, I've lost count on the number of times I've passed the traffic on the one ahead, to recieve the reply "Ummm, we can't see them, got them on TCAS". Often makes me scratch my head as to what exactly is being implied.
As we often run visual approaches here in the frozen north, I've lost count on the number of times I've passed the traffic on the one ahead, to recieve the reply "Ummm, we can't see them, got them on TCAS". Often makes me scratch my head as to what exactly is being implied.
Nothing really. The TCAS will aid me in finding the traffic once you point it out. If as in the enroute environment we receive traffic calls well outside of viewing distance, I can keep myself updated to its position in relation to me. Given that, I don't really expect too many updates once I say I see it on the metal detector. Not required by SOP or practice, I guess you could make an argument it borders on excessive verbiage.
Ohcirrej
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Thanks Westy. I know you and I have been here before about "situational awareness" and is the traffic on your TCAS actually the one I'm pointing out to you.
Excessive verbage is a good description, but I would hate to think a driver, having supposedly identified the pointed out traffic on the box, but never visually aquiring it then bases a "visual" call solely on the TCAS showing a target in the general direction (can anybody remind me of the azmiuth error please) correclating to traffic they can see there.
Excessive verbage is a good description, but I would hate to think a driver, having supposedly identified the pointed out traffic on the box, but never visually aquiring it then bases a "visual" call solely on the TCAS showing a target in the general direction (can anybody remind me of the azmiuth error please) correclating to traffic they can see there.
Can't say as I have or have I seen anyone else call traffic in sight solely off the TCAS. Bad habit if they do. I would be afraid in some situations to do it. I could see doing it while not actually seeing the plane. This to be followed by something to the effect of maintain visual separation, the traffic will climb through your altitude. Likely cause the liar to fess up.
Strikes me that visual acquisition is one of the least reliable of methods of keeping aircraft apart. It's all too easy to sight an aircraft, and then, because of the background clutter or change in motion geometry, lose it again. The most famous example happened in West Coast's back yard. At least a contact, once on TCAS, tends to stay on TCAS.
Jerricho, what do you expect as a response to your traffic call? Are you using it for reducing standard separation? If so, do you accept "traffic in sight" as the criterion for reducing separation, or do you require a positive confirmation that the pilot of the following aircraft can maintain visual separation?
Jerricho, what do you expect as a response to your traffic call? Are you using it for reducing standard separation? If so, do you accept "traffic in sight" as the criterion for reducing separation, or do you require a positive confirmation that the pilot of the following aircraft can maintain visual separation?
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At least a contact, once on TCAS, tends to stay on TCAS.
Especially in the example given above, all that you know is that you've got some target on your TCAS. In Jerricho's example, that's not worth a thing. It could be anything, it could be totally different from the target Jerricho is trying to point out.
Jerricho, keep scratching your head. If the reply is 'we can't see him but he's on TCAS' I would advise you to ignore the last part. They can't see him. Period.
Ohcirrej
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Bookworm, the response I am looking for one of two responses:
"Visual with the traffic", in which case the pilot will be cleared for the approach and instructed to follow the preceeding or;
"Not visual", in wich case I will vector them and be responsible for separation.
(Here in Canada, there isn't the same "reduced separation in the vicinity" as in the UK.)
As I mentioned, I am just curious as to the "got him on TCAS" call, as it means nothing to ATC, they're still going to separate you. Yet it's something I hear on a daily, if not hourly basis.
"Visual with the traffic", in which case the pilot will be cleared for the approach and instructed to follow the preceeding or;
"Not visual", in wich case I will vector them and be responsible for separation.
(Here in Canada, there isn't the same "reduced separation in the vicinity" as in the UK.)
As I mentioned, I am just curious as to the "got him on TCAS" call, as it means nothing to ATC, they're still going to separate you. Yet it's something I hear on a daily, if not hourly basis.
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Scott,
You didn’t read the full text of my message. US are a signatory to the ICAO convention. That to me, means that they agree to abide by the rules. If every signatory did the same, then we would not be in the silly mess we find ourselves in. Can you imagine a basketball or baseball game being played with differing rules being applied to either team? Mayhem!! And that’s what we’ve got.
So how best to fix it then?
Agreed, the ICAO change from “holding point” to “holding position” was a disaster. They however, have recognised this fact and have changed back. To me that shows an understanding of the issues and how best to resolve them. The “be reasonable – do it my way” approach is not appropriate here.
My hope is that such a lead can be followed by others, especially so in this case where on our side of the pond, the issue of runway incursions gives us so much grief, especially where the procedures are applied differently dependant on where the aircraft concerned comes from.
A touch of reasonableness I think should prevail, and the high horse attitude knocked over.
You didn’t read the full text of my message. US are a signatory to the ICAO convention. That to me, means that they agree to abide by the rules. If every signatory did the same, then we would not be in the silly mess we find ourselves in. Can you imagine a basketball or baseball game being played with differing rules being applied to either team? Mayhem!! And that’s what we’ve got.
So how best to fix it then?
Agreed, the ICAO change from “holding point” to “holding position” was a disaster. They however, have recognised this fact and have changed back. To me that shows an understanding of the issues and how best to resolve them. The “be reasonable – do it my way” approach is not appropriate here.
My hope is that such a lead can be followed by others, especially so in this case where on our side of the pond, the issue of runway incursions gives us so much grief, especially where the procedures are applied differently dependant on where the aircraft concerned comes from.
A touch of reasonableness I think should prevail, and the high horse attitude knocked over.
Especially in the example given above, all that you know is that you've got some target on your TCAS. In Jerricho's example, that's not worth a thing. It could be anything, it could be totally different from the target Jerricho is trying to point out.
As Jerricho pointed out, there is an azimuth error inherent in TCAS (30 degrees iirc).
That's where the danger lies in using TCAS to 'identify' target aircraft.
But with the additional situational awareness afforded by TCAS, when the aircraft pops out of the clouds and traffic is seen, wouldn't the crew then be entitled to call visual ? provided they give a range and bearing to target aircraft that checked with the radar information ?
Does this example save RT loading by obviating the need for further traffic info ? after all, standard separation is still applied till the aircraft is visual.
Maybe 'we have him on TCAS' , in some cases at least, means we'll keep a look out and call you when we're visual.
That's where the danger lies in using TCAS to 'identify' target aircraft.
But with the additional situational awareness afforded by TCAS, when the aircraft pops out of the clouds and traffic is seen, wouldn't the crew then be entitled to call visual ? provided they give a range and bearing to target aircraft that checked with the radar information ?
Does this example save RT loading by obviating the need for further traffic info ? after all, standard separation is still applied till the aircraft is visual.
Maybe 'we have him on TCAS' , in some cases at least, means we'll keep a look out and call you when we're visual.
Mostly Harmless
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"position and hold"
Maybe coz everybody else on earth will think about the instruction for a bit, than agree to hold where ever they are and report their position.
Back to the thread...
If the TCAS has gone off the controller has (probably) already farked it up (unless the other traffic is unknown to him/her/it). We have to be mindfull that if we notice traffic in unsafe proximity and attract the attention of one aircraft and take some sort of action the other may be reacting to the beeping on the dashboard.
This 5 degree bank thing is a worry, we currently take the above to mean vector like mad in such collision avoidance situations, and leave the vertical to the gizmo????
Our radar gear is designed to help us preserve separation standards, so it's ok to be about 6 seconds behind reality.
Maybe coz everybody else on earth will think about the instruction for a bit, than agree to hold where ever they are and report their position.
Back to the thread...
If the TCAS has gone off the controller has (probably) already farked it up (unless the other traffic is unknown to him/her/it). We have to be mindfull that if we notice traffic in unsafe proximity and attract the attention of one aircraft and take some sort of action the other may be reacting to the beeping on the dashboard.
This 5 degree bank thing is a worry, we currently take the above to mean vector like mad in such collision avoidance situations, and leave the vertical to the gizmo????
Our radar gear is designed to help us preserve separation standards, so it's ok to be about 6 seconds behind reality.
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But why is that different to a visual contact, Phoenix_X? It's just a shape in the distance -- it doesn't have an id-tag attached. At least on TCAS I'd know its level and probably have a better idea of its relative motion
. Except for maybe seeing the a/c type and company, it's not much better than TCAS. I won't argue that!However, the point remains that thinking you're clear of a TCAS target, may not
A) Mean you're actually clear due to the position error
B) Mean that you're clear of the aircraft that's conflicting with you
At least if you actually see an aircraft point (A) is solved. I agree (B) is not. Thanks for the heads-up!
As Jerricho pointed out, there is an azimuth error inherent in TCAS (30 degrees iirc).
That's where the danger lies in using TCAS to 'identify' target aircraft.
That's where the danger lies in using TCAS to 'identify' target aircraft.
Bookworm, a valid point. I believe the problem arises when 11 o'clock traffic appears at 1 o'clock on TCAS. The clock code will always tell you whether traffic is left or right. (providing the controller doesn't get it wrong 
)
Can anyone else confirm the 5 degree bank limit when taking avoiding action ?
)Can anyone else confirm the 5 degree bank limit when taking avoiding action ?
"Can anyone else confirm the 5 degree bank limit when taking avoiding action ?"
Are you talking about action initiated by ATC or the TCAS? TCAS RA's provide no lateral instructions in the escape manuever, strictly in the vertical.
Are you talking about action initiated by ATC or the TCAS? TCAS RA's provide no lateral instructions in the escape manuever, strictly in the vertical.
Ohcirrej
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I have a similar question about banking/turning during an RA manoeuvre. Hammy will probably tell the story better, but was privy to a situation where a potential TCAS RA situation was about to unfold and the controller issued avoiding action involving a turn was given. Moments later "*** TCAS climb" came over the r/t and it looked as if the turn stopped. SOPs?