Primarily for general aviation discussion, but other aviation topics are also welcome.
#1645361
Personally, I would have...

Traffic in sight - no need for further updates.

Traffic not sighted - update further as necessary.

Roger - if not advised sighted/not sighted by pilot in due course, update further as necessary.

Got it on TCAS - equates to traffic not sighted or roger as far as the controller is concerned. Edit - actually no, for me equates to traffic not sighted for all intents and purposes.

Criterion for traffic not sighted or roger? If you find ambiguity in air traffic services useful, say roger when you could have said sighted/not sighted.

That said, it may be a pilot can’t immediately come back with a sighted/not sighted response so justifiably says roger. But I’d have hoped for an update asap in order to plan/provide/not provide updates accordingly (especially if providing the service as a secondary task).
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By TC_LTN
#1645448
I agree with Mike's interpretation but would still ask your consideration of incorporating an electronic depiction of partially detected multiple contacts into a traffic scenario.

Below is a depiction of a surveillance display being used by a radar controller to provide a traffic service;
Image

G-ABCD is in receipt of a traffic service. The controller has just passed the following traffic information;

"Traffic left, 10 o'clock range 2 miles converging, no height information and further traffic left, 10 o'clock range 2 1/2 miles indicating 200ft below, should pass down your left-hand side"

The pilot looks to his/her left and sees an aircraft slightly below passing down his/her left hand side. The pilot also notes their SkyDemon traffic display connected to PAW indicating the following;
Image

Which aircraft pointed out is depicted on SkyDemon and is he/she immediately in conflict with another aircraft?

Or, you receive the same traffic information but your SD traffic display connected to PAW shows you this;
Image

Which aircraft is depicted on SkyDemon? Which did he/see out of the window?
#1645453
flybymike wrote:
Criterion for traffic not sighted or roger? If you find ambiguity in air traffic services useful, say roger when you could have said sighted/not sighted.

And if you like further ambiguity, use the daft phrases
“Traffic sighted”/“Traffic not sighted”


What's ambiquous? Better than the spamcan driver who insisted on keep saying; 'Tally' and 'Tally-ho" in response to traffic information, last week.
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By Gertie
#1645454
flybymike wrote:And if you like further ambiguity, use the daft phrases
“Traffic sighted”/“Traffic not sighted”

I know this has been done before, but I still don't get what was wrong with the unambiguous "traffic in sight" or "negative contact" that I was brought up with.
#1645455
Gertie wrote:
flybymike wrote:And if you like further ambiguity, use the daft phrases
“Traffic sighted”/“Traffic not sighted”

I know this has been done before, but I still don't get what was wrong with the unambiguous "traffic in sight" or "negative contact" that I was brought up with.

Nothing wrong with it but you were just brought up using the wrong phrase. I deal, day in, day out, with pilot's making up bits of phraseology or just using non-standard phraseology. Most of the time it doesn't really matter, just occasionally it does.
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#1645459
TC_LTN asked again
Which did he/see out of the window?


In either senario what does it matter? You can see one contact with Mk1 and one on SD, they may or may not be the same plane, that will probably become obvious shortly if it hasn't already. But if you need to take evasive action from either, you can. All the time you are still scanning the sky for any other aircraft, the possible 2nd you have been told about and the 3rd or 4th or 5th that you haven't been told about but that might still be there. Because not even radar sees EVERYTHING.

In reality such a situation is unlikely to happen, aircraft do not suddenly appear on EC 1.5 miles away, you see them long before or not at all (unless bearingless but that's a different scenario). If on a converging course at a similar height (which is actually quite rare), I certainly adjust my track and or height long before they get uncomfortably close or if there is a gaggle of gliders a few miles ahead adjust my course to give them a wide berth. Therefore I often never actually see the EC contacts with the MK1 eyeball despite looking, because I've made sure they are a safe distance from me. It's invariably the non EC contacts that are the close ones.
#1645478
Mike Tango wrote:Personally, I would have...

Traffic in sight - no need for further updates.

Traffic not sighted - update further as necessary.


I agree that implicitly that's exactly what is intended. But there's nothing in CAP 413 or CAP 774 to make that link.

While "got it on TCAS" is not standard phraseology, does it not have exactly the same implication, that the pilot is able to monitor the development of a potential conflict without further updates?

In fact, I would say that it's more likely that visual acquisition would be subsequently lost than TCAS acquisition. Not sure about other forms of EC.
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By T67M
FLYER Club Member  FLYER Club Member
#1645479
TC_LTN wrote:
flybymike wrote:And if you like further ambiguity, use the daft phrases
“Traffic sighted”/“Traffic not sighted”


What's ambiquous?


"Traffic...err...{static} sighted"

In an unreliable link, such as speech radio, positive and negative messages should be significantly different rather than relying on a single negating syllable such as "not", "un" etc.
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By James Chan
FLYER Club Member  FLYER Club Member
#1645481
I see “Negative contact” is the standard ICAO phrase. (Section 6.4 in ICAO 9432)

“Traffic not sighted” is a UK peculiarity.
Last edited by James Chan on Thu Oct 18, 2018 8:18 am, edited 1 time in total.
#1645483
TC_LTN wrote:Nothing wrong with it but you were just brought up using the wrong phrase.


I'm pretty confident that "negative contact" used to be the right phrase.

PANS ATM Doc 4444 14ed (2001) gives the following ICAO standard responses

*c) LOOKING OUT;
*d) TRAFFIC IN SIGHT;
*e) NEGATIVE CONTACT [reasons];

I believe the change in the UK was made about 5 years ago.

I share flybymike's frustration that the old way was better, because the phrases "traffic in sight" and "negative contact" are much more easily distinguished than "traffic in sight" and "traffic not sighted".
johnm, James Chan, GrahamB and 3 others liked this
#1645488
TC_LTN wrote:n the spamcan driver who insisted on keep saying; 'Tally' and 'Tally-ho" in response to traffic information, last week.


I know it's wrong and very bad of me, but I have a grudging admiration for that man. 8)

Rob P
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#1645492
bookworm wrote:
While "got it on TCAS" is not standard phraseology, does it not have exactly the same implication, that the pilot is able to monitor the development of a potential conflict without further updates?


In theory I guess yes, but in current practice in line with current procedures as I last knew them, no.

It would need rules/procedures/guidance to be changed to be considered an acceptable response following which no further traffic updates from ATC were required.
#1648299
leemoore1966 wrote: does anybody recall the CAA instigated a survey in August of 2017 for types of EC used by Pilots. [...] I have never seen the content published - and its now over a year old, the survey closed on 29/Sept/2017 [...]
I wonder what the holdup is ?


It's now published in CAP1726.
Minimum analysis and conclusion. No announcement.


[edit]Typo[/edit]
Last edited by xtophe on Thu Nov 01, 2018 10:06 am, edited 1 time in total.
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By Dave W
FLYER Club Member  FLYER Club Member
#1648300
CAP1726 wrote:Conclusions:
 89% pilots surveyed agree that full electronic conspicuity would benefit GA safety
 The only group having different views are balloon pilots – further discussions needed
 Lower price is the main factor which would encourage pilots to adopt Low Power ADS-B –
device for under £250 could potentially be adopted by 86% of pilots.
 44% pilots currently use Mode S so it is important that new device can be used with existing
Mode S
 CAP1391 is focused on benefits-led approach and survey shows that safety related benefits
are most important for GA pilots.
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