Talk:Traffic collision avoidance system

TCAS is a proprietary system. "Airborne collision avoidance system" is a generic term covering all such systems. Who has redirected the latter to the former? This is like redirecting "Aspirin" to "Bayer aspirin."PrairieOjibway (talk) 19:56, 27 March 2009 (UTC)

I Am currently working on a project at the ECAT (European Center for Aerospace Training) that would develop the current TCAS system into somthing that could improve international airspace dramatically and reduce delays greatly. If anyone has any information or circuit diagrams that may be relevant to this research (Especially systems that may use longitude and latidue), please e-mail me at stato62@hotmail.com or leave a message on my answer phone (+44) 0114 3311408. Many thanks, Sam - 12 November 2007

This is really not the place for this. Xihr 19:57, 12 November 2007 (UTC)

I'm currently working on this article, but feel free to work on this if you like; I would especially like ideas on how to structure this article so it is friendly for readers with little background on aviation issues. -- Alanl 09:33, 21 January 2006 (UTC)

I'm currently working on my final year project which has to do with collision avoidance, please I am looking forward to hearing from you all on what ever you know about this topic and relevant circuit diagrams to support. You can reach me at slim525@engineer.com and oluwatomilola.o.ayeni@exxonmobil.com. -- Tomi 14:09, 26 June 2006

Eurocontrol is not a regulatory agency, nor is ICAO. The European regulation that requires the carriage of ACAS is probably from EASA, but at the moment I cannot locate chapter and verse. -- treesmill 12:34, 8 August 2006 (UTC)

PCAS is a proprietary system unrelated to TCAS. Unless I see a reasonable argument to the contrary in a few days I shall remove the references to it from the TCAS article. -- treesmill 15:15, 1 September 2006 (UTC)

I have revised and expended the article (incorporating the above comments). I think it is improved but could still do with an expert's revision. -- FirstPrinciples 04:44, 5 October 2006 (UTC)

How many passenger seats?

In the introduction, it says that TCAS must be fit in an aircraft with at least 19 passenger seats. In the table at the bottom it says 30 seats. A recent article in Slate says that it must be fit to all planes with more than 10 seats. So which one is it now? The current figures, 19 and 30, are not referenced. --ZeroOne (talk | @) 09:36, 5 October 2006 (UTC)

I don't have access to the ICAO Annex at present, but I believe that the figure of 19 or 5700 kg is correct for that reference, however, ICAO annexes are Standards and Recommended Practices, not regulations, and it may be that the regulatory authorities referenced later have different requirements and the figures in the article are correct. I'll check next week. treesmill 16:02, 6 October 2006 (UTC)

relationship to Automatic Dependent Surveillance?

Does TCAS use the same broadcast radio signals as Automatic Dependent Surveillance? Can it use those same signals? If so, this article should say so; if not, this article might want to mention that the two systems are distinct, or that one obsoletes/supersedes the other (whichever the case may be). —Steve Summit (talk) 18:51, 4 November 2006 (UTC)

I've added some information about using ADS-B messages with TCAS. Maybe someone with more in-depth knowledge could add more details on hybrid surveillance. Richwing 17:07, 8 November 2006 (UTC)

AIS-P

The material on AIS-P doesn't appear to belong in this article. It's presented as additional information in the section on TCAS Basics, but since it is discussed as an alternative technology, should probably be presented in an article of its own. There appear to be several places throughout WP that have had similar AIS-P material added recently. All these separate treatments could be collected into one article dedicated to the topic. PhilosopherBruce 08:36, 26 December 2006 (UTC)

Biased against airspace fees?

In the Drawbacks section, there is "By declaring position and velocity and unique name, this allows for billing each aircraft for ATC time in the air." This seems unnecessarily biased against airspace fees. I don't support ATC user fees due to safety issues, but this reads like a cheap shot to me. -- 74.134.114.185 18:13, 20 January 2007 (UTC)

Removed paragraph from "Current implementation"

I'm taking out the following text from the section "Current implementation":

There are also some interesting combinatorial implementations of TCAS II along with Mode S transponder and ATCRBS transponder systems. For example, in the case of a conflict between a 234 hour old 737-800 and a new Legacy 600, about 30 km. from Peixoto de Azevedo in the Brazilian state of Mato Grosso, at FL370 a point about 460 nautical miles north-northwest of BRS, on airway UZ6, each aircraft with the newest TCAS II, on September 29th, 2006, it is suspected that the Honeywell TCAS II did not have its ATCRBS squawk code dialed in by its operator on the Legacy 600 within the limit of 5 seconds (perhaps distraction reduced the mandatory dialing speed proficiency for commercial pilots required by this Honeywell equipment). This may have caused the Mode S transponder to go entirely off-line for 50 minutes before the collision. One result would cause the TCAS II on the 737-800 to not be able to see the target dead ahead at the same altitude. The other result would be to also have caused ATC to experience drop out with the subsequent coast mode showing the Legacy 600 at its pre-flight filed paper flight plan altitude 1000 feet in difference to the ATC more recently assigned altitude clearance. By connecting the transmission function with the reception function, the third result would then also have caused the TCAS II system in the Legacy 600 to go entirely off-line for 50 minutes before the collision, which caused the Legacy 600 TCAS II to be unable to see the target dead ahead at the same altitude.

Rationale

• Text is entirely unclear. I can't even figure out if the planes collided in the end or not (mentions "the collision" like a fact, but uses "would" for describing the results as if they're speculative)
• Bad style (second sentence has some 5 lines)
• Unexplained terms, lots of them (UZ6? Mode S transponder? ATCRBS squawk code?)
• Dubious terms (combinatorial implementation? Combinatorics is a branch of mathematics dealing with collections of objects)
• Unspecific. "Some interesting implementations": What's interesting about them?
• Odd linkage ("Sept. 29th 2006" links to a blog--not an entry, but the front page)

Rewriting the paragraph would be a good idea, because there's a nice anecdote in there (I imagine). Unfortunately I just don't understand it. --193.99.145.162 00:46, 4 February 2007 (UTC)

As far as I remember the only instructions that take precendence over a TCAS RA are GPWS and wind shear (which is also GPWS). No mentioning of stall warning. Can anyone confirm what the hard/soft order of warnings is for a particular type, or could anyone reference an electronic ops manual? -- Sonicflight (talk) 17:21, 16 November 2007 (UTC)

RA Definition

The term TCAS RA is mentioned before the text "Resolution Advisory". Any chance of putting this acronym nearer the top? People search for this term (from outside the world of aviation) such as myself might be otherwise confused as to it's meaning. Given the prevalence of TCAS II in Commercial Airliners, might it be suitable to include this term in the page summary? -- 82.70.110.134 (talk) 00:09, 21 January 2008 (UTC)

TCAS warning sounds

Why don't we add this section on the wiki? I heard people have been wandering what a TCAS 'warning sounds' sounds like. Can any of you put a media file or just an article like "lists of TCAS warnings"? Some of the warnings that I know: "descent, descent" "increase descent" "climb, climb" "increase climb" Just an idea to improve the page. —Preceding unsigned comment added by 218.185.9.242 (talk) 10:59, 28 October 2008 (UTC)

More Sources/Links (TCAS Limitations)

• http://techaidproducts.com/PDFs/TCASUncovered.pdf
• http://www.arinc.com/downloads/tcas/tcas.pdf —Preceding unsigned comment added by Parallelized (talk • contribs) 19:05, 17 February 2010 (UTC)
• TCAS/ACAS Limitations
• Exploration of Algorithms for the NextGen Collision Avoidance System
• Autonomous In-Flight Path Planning to replace pure Collision Avoidance for Free Flight Aircraft using Automatic Dependent Surveillance Broadcast
• http://crewtraining.se/LFT_NEWS_021202.HTM
• http://www.sisadminov.net/tcas/docs/TCAS_II_V7.pdf
• http://www.caasd.org/work/project_details.cfm?item_id=153
• http://www.dicksmithflyer.com.au/article_67.php
• http://www.dicksmithflyer.com.au/Ten_years_of_aviation_safety_neglect.php
• http://www.eurocontrol.int/acas/
• http://www.honeywelltcas.com/products_pages/cas81_6mcu/cas81_pilotguide.pdf
• http://dspace.mit.edu/bitstream/1721.1/38468/1/Lester-ADS-B.pdf
• http://www.mitre.org/news/events/exchange08/3869.pdf
• http://www.eue24.net/pi/index.php?StoryID=253&articleID=160945
• http://www.flightglobal.com/articles/2001/07/24/133771/tcas-and-its-limitations.html
• http://www.narcap.org/articles/205s001.pdf
• http://www.airliners.net/aviation-forums/tech_ops/read.main/954/
• http://www.pprune.org/tech-log/345780-tcas-ra-aircrafts-certified-ceiling.html
• http://www.pprune.org/questions/337186-does-tcas-know-aeroplanes-performance-limitations.html

--Parallelized (talk) 23:56, 2 April 2009 (UTC)

TCAS Issues

• http://www.eurocontrol.int/sites/default/files/content/documents/nm/safety/ACAS/safety-acas-collision-risk-due-to-tcas-safety-issues-20100510.pdf
• http://www.ifalpa.org/downloads/Level1/Briefing%2520Leaflets/Air%2520Traffic%2520Services/12ATSBL04%2520-%2520TCAS%2520pilot%2520training%2520issues.pdf
• http://www.skybrary.aero/bookshelf/books/101.pdf — Preceding unsigned comment added by Parallelized (talk • contribs) 10:27, 19 February 2013 (UTC)
• http://asrs.arc.nasa.gov/publications/directline/dl4_tcas.htm — Preceding unsigned comment added by Parallelized (talk • contribs) 13:04, 16 August 2012 (UTC)
• http://asrs.arc.nasa.gov/docs/cb/cb_321.pdf
• http://www.tls.cena.fr/divisions/SAS/doc/Public/SICASP/stockholm94/NT94-1.ps.gz
• http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=331148
• http://www.narcap.org/articles/892905.pdf
• http://www.nytimes.com/1989/05/26/opinion/l-collision-avoiding-device-needs-uncrowded-skies-problems-abound-376189.html?pagewanted=1
• http://www.airliners.net/aviation-forums/tech_ops/read.main/43240/
• http://www.princeton.edu/~ota/disk1/1989/8929/892906.PDF
• http://www.patent-de.com/20090122/DE102007032084A1.html
• http://answers.yahoo.com/question/index?qid=20081115015029AAesJxu
• http://asrs.arc.nasa.gov/publications/directline/dl4_tcas.htm
• http://www.iasa.com.au/folders/Safety_Issues/RiskManagement/skyguided-3.html
• http://www.icao.int/anb/panels/scrsp/meetings/ASP%20Working%20Group%2019%20to%2023%20May%202008r/WP%20ASP04-34%20Analysis%20of%20TCAS%20responsibility%20issues.doc
• http://journals.cambridge.org/production/action/cjoGetFulltext?fulltextid=331148
• http://www.freepatentsonline.com/EP1147506.html
• http://ieeexplore.ieee.org/iel2/3487/10318/00482819.pdf
• http://www.flightsafety.org/asw/apr09/asw_apr09_p34-37.pdf
• http://www.cs.virginia.edu/~wsg6p/docs/slides/false_advice.ppt
• http://www.ecacnav.com/content.asp?PageID=77
• http://portal.acm.org/ft_gateway.cfm?id=1082339&type=pdf
• http://www.afceaboston.com/documents/events/cnsatm2007/presentations/2007%20CNSATM%20Presentations/101%20Tutorials/Surv/Traffic%20and%20Collision%20Avoidance%20System%20(TCAS)%202007%20Conference%20Tutorial.pdf
• http://www.copac.es/direcciones/Seguridad/seguridad-ATC/BOLETIN%20ACAS/Bolet%C3%ADn%20ACAS%20N%C2%BA4%20TCAS%20II%20and%20VFR%20traffic.pdf
• http://adsb.tc.faa.gov/TCAS/CPs/CP116.pdf
• http://ieeexplore.ieee.org/iel2/610/4750/00185847.pdf?arnumber=185847
• http://www.airliners.net/aviation-forums/tech_ops/read.main/43187/
• http://web.mit.edu/aeroastro/www/labs/ASL/PRO_DASC/pro_dasc.html
• http://www.questia.com/PM.qst?a=o&se=gglsc&d=5008765282
• http://www.accessmylibrary.com/coms2/summary_0286-37982660_ITM
• http://www.emeraldinsight.com/Insight/ViewContentServlet?contentType=Article&Filename=/published/emeraldfulltextarticle/pdf/1270620406.pdf
• http://www.icea.gov.br/ead/ACASII/material/novo/TCAS.pps
• http://www.washingtonexaminer.com/opinion/columns/BarbaraHollingsworth/Study-found-nine-daily-near-misses-at-Bostons-Logan-Airport-44581187.html
• http://www.skybrary.aero/index.php/Solutions_talk:TCAS

Safety studies

FTA: "Safety studies on TCAS estimate that the system improves safety in the airspace by a factor of between 3 and 5." -- does that mean that 2/3 - 4/5 of accidents were prevented? Should that paragraph link to some references? Ojw (talk) 15:20, 20 October 2008 (UTC)

Please give us an example.

As a layman reading this out of fascination, I think the article needs an example of how TCAS would work. An example could be: aircraft A and aircraft B are fitted with TCAS. A and B could collide if no action is taken. In this example, how would TCAS actually help?

I think an example would make the article easier to understand and make it more fascinating.

Thank you for reading. :) TurboForce (talk) 00:22, 14 March 2010 (UTC)

TACAS

I fail to see how "traffic alert and collision avoidance system" abbreviates to "TCAS." Wouldn't it abbreviate to "TACAS?" Whoop whoop pull up (talk) 00:56, 30 September 2010 (UTC)

The title of the article, and the system is Traffic Collision Avoidance System, or TCAS for short. -SidewinderX (talk) 11:38, 30 September 2010 (UTC)

Multithreat in Limitations

"TCAS was specifically designed to handle 2-way conflicts between just two aircraft, more complex conflict scenarios such as 3-way conflicts are not supported by the current design and TCAS has been reported to perform badly under such circumstances [3] [4]"

This is factually incorrect. TCAS (v7.0, I believe 6.04A as well) supports multiple threat encounters(conflicts with more than 1 intruder). The threat logic generates a response against each intruder and then has rules to produce a final RA which attempts to provide separation from both intruders. While separation is more complex, not guaranteed, and may lead to problematic encounters, the scenarios are supported by TCAS and provide a safety benefit. This can all be found in the "Introduction to TCAS II" documents and MOPS.

The citation provided is just a forum thread with people guessing what happens. I am removing the sentences. — Preceding unsigned comment added by Soccerpall86 (talk • contribs) 03:52, 1 November 2012 (UTC)

External links modified (January 2018)

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I have just modified 28 external links on Traffic collision avoidance system. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

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