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Please, there are some fundamental issues not explained in this article, and could be better written in order to a non expert person, like me, understand it.
I think that those issues must be better explained here. Only experts can understand this article. Lmc9 ( talk) 00:50, 10 December 2009 (UTC)
Crum375, thank you very much for your explanations, but it seems to me that you are an “expert” reader of those huge reports, and by your high quality comments, you do not even need Wikipedia to understand this accident. It’s impossible to us (me), that just travel by planes understand those technical reports. I think that Wikipedia, as an online encyclopedia, should use a language and explanations that an “average” reader can understand it, something like “Gol flight 1907 collision for dummies”. I think, just an opinion for the guys that write here, that they should read your comments posted here and them complete the article, explaining those issues. But one thing I don’t understand in what you said (don’t think I am too stupid, but I’m not an “aircraft expert”). You said “This is done by ATC "clearing" blocks of airspace at given locations, times and altitudes for individual aircraft”. How ATC clears blocks of airspace for individual aircraft if they don’t see them in radar screen? It is said here it “disappeared completely from the radar screen”. How can they separate them without seeing them in radar screen? How ATC knows where is aircraft? How they know that the aircraft have not crashed? How they know that another aircraft that has just departed is not crossing its way? How they know that an aircraft is not in the wrong way by an instrument failure? I’ve read somewhere that ATC amends aircraft altitude all the time, asking them to climb and descend, due to winds, weather and other aircrafts that crosses their way. How they can amend altitude without knowing where is aircraft? What for radar is used? How ATC can do their work without radar? All these issues are not answered in this article. Thank you again, but I think that this article misses a lot of thinks. We read it and keep not understanding why this tragedy happened. Lmc9 ( talk) 11:37, 10 December 2009 (UTC)
Crum, there are more fundamental issues not explained in this article:
Regards, Lmc9 ( talk) 15:04, 12 December 2009 (UTC)
Crum, if you allow me, I can help you. 1) Crew awareness - CENIPA says that "(...) according to the interviews, the flight crew showed a lack of attention to the flight plan and was not able to interpret the routes and flight level changes prescribed in item 18 of their ICAO flight plan form". According "to the CVR data, the pilots did not make any comments concerning the flight management, such as, for example, the thirty-degree heading change to the left (from 006º to 336º) at the vertical of BRS VOR [Brasilia]. There were no comments about the joining of the new airway, or the possibility of a flight level change. The left turn was made automatically by the autopilot, and the CVR did not record any supervising action by the crew at that moment". And follows "When, at an interview, the crew was asked about having entered a wrong flight level for the heading they were flying, they said it is not uncommon to receive non-standard levels from the air traffic control [indeed, it is very, very uncommon as you can check by yourself, monitoring flights online]. According to them, they were flying en route, under radar contact, and did not receive any instruction from the control unit whose frequency they were monitoring. They were in accordance with the last instructions received". So, apparently they were not aware. 2) Flight plan - The file plan profile had been produced by the software of an American commercial flight planning service program considering the winds aloft available at the several WIND ALOFT charts for the FL300, FL340 and FL390. This is a long story, but making it short, CENIPA says that the navigation presented to crew was rather "unusual". Nobody is able to explain it, because those charts are valid for 12 hours, and they asked the flight plan a few days before departure. 3) Clearance - Yes, it was an ordinary clearance issued by airport towers, but has omitted "then as filed" or also could be said "limit Brasilia". 4) Transponder status not observed - Since the beginning of the recording of the Legacy CVR, the PIC and SIC were together using a notebook to calculate and obtain data of the landing and takeoff performance relative to Manaus. The crew was learning how to use it in the calculation of the aircraft weight and balance. There was a distraction from the focus of the routines relative to the monitoring of the flight progress, which made the crew direct their attention to the search and analysis of the available data relative to the remaining fuel, as well as the information contained in the software of the notebook, during a long time, possibly longer than the one that was recorded in the CVR. Between 19:00:01.5 UTC and 19:01:44.3 UTC occurs the interruption of the transponder transmission. The pilots confirmed that, at this moment, the SIC was with the laptop and worked on it alone during the two minutes; he neither passed it to the PIC, nor placed it next to the panel. The PIC, who had declared in his last interview not recalling exactly what he had been doing during this period of silence, may have been still focused on their calculation of the fuel for the departure from Manaus (seemingly) to check the current fuel status of the N600XL. The subject of the drawing of the attention of the crew to it was only solved (closing of the notebook), approximately 11 minutes after the transponder had stopped transmitting. There was a distraction from the focus of the routines relative to the monitoring of the flight progress, which made the crew direct their attention to the search and analysis of the available data relative to the remaining fuel, as well as the information contained in the software of the notebook, during a long time, possibly longer than the one that was recorded in the CVR. They didn't observed the instruments, because during this long period of time, they were working with a notebook in the cockpit, which is prohibited by many commercial airlines and even led to FAA revoke the pilots certificates in the recent incident of Northwest Airlines Flight 188. Herbmartin ( talk) 01:55, 13 December 2009 (UTC)
These are my comments about this article, and if editors allow me, I would like to edit it.
Gol Transportes Aéreos Flight 1907
This article says:
“The accident was investigated by both the Brazilian Air Force Centro de Investigação e Prevenção de Acidentes Aeronáuticos (CENIPA) and the U.S. National Transportation Safety Board (NTSB), with a final report issued on December 10, 2008. CENIPA concluded that the accident was caused by errors committed both by air traffic controllers and by the Embraer's pilots, while the NTSB determined that all pilots acted properly and were placed on a collision course by a variety of "individual and institutional" air traffic control errors”.[1][2][6][7]
The sentence “NTSB determined that all pilots acted properly” is nonspecific, cannot be verified, and was extracted of its context. Indeed, what NTSB says is that “there was no evidence of regulatory violations”. This does not mean that “pilots acted properly”. NTSB even recognizes some crew mistakes, as for instance, “[...] they did have a long term opportunity to note a nonstandard situation and request clarification or confirmation from ATC. For about 1 hour the significance of the long time period spent at a nonstandard cruise altitude for the flight direction by N600XL was not recognized”, and “Without question, N600XL proceeded for an inordinately long time without two-way communication”.
Therefore, the sentence should be corrected to:
The accident was investigated by both the Brazilian Air Force Centro de Investigação e Prevenção de Acidentes Aeronáuticos (CENIPA) and the U.S. National Transportation Safety Board (NTSB), with a final report issued on December 10, 2008. CENIPA concluded that the accident was caused by many errors committed both by air traffic controllers and by the Embraer's pilots and doesn’t point a single cause. Whereas NTSB argues that none of the errors committed by Embraer’s pilots pointed by CENIPA are evidences of regulatory violations, and they flew the route precisely as cleared and complied with all ATC instructions. NTSB concludes that accident probable cause was that aircrafts were placed on a collision course by a variety of "individual and institutional" air traffic control errors. [1][2][6][7].
Embraer aircraft and crew
The topic omits an important issue and should be amended with:
CENIPA says that Embraer’s crew had little experience of the N600XL, and had never flown together as part of the same crew. The experience of the pilot-in-command in the installed avionics of the Embraer airplane was restricted to the hours spent in the simulator, plus the 5 hours and 35 minutes of flight time prior to the accident. Even though the second-in-command was already certified in a similar Embraer model, with a total of 368 hours flown, the company decided to send him for a complete training program. [1]
Embraer flight and communication sequence
“At 16:02, seven minutes after crossing the Brasilia VOR, secondary radar contact was lost with the Embraer, thus stopping the display of the Embraer's reported altitude (Mode C) on the controller's radar screen.[note 12].”
This sentence leads the reader to understand that there was a radar failure. It is not explained that secondary radar relies on transponder signal. These are the crucial moments, fundamental to accident comprehension. It should be more detailed. I would redact the topic this way:
At 16:02, seven minutes after crossing the Brasilia VOR, secondary radar contact was lost with the Embraer, thus stopping the display of the Embraer's reported altitude (Mode C) on the controller's radar screen. According to the information available, the loss of the Transponder signal indicates that the STANDBY feature of the transponder had probably been selected.
CENIPA says that “the analysis of the CVR showed that the atmosphere in the cockpit was rather relaxed, with the pilots working with a notebook. According to the CVR data, the pilots did not make any comments concerning the flight management, such as, for example, the thirty-degree heading change to the left (from 006º to 336º) at the vertical of BRS VOR. There were no comments about the joining of the new airway, or the possibility of a flight level change. The left turn was made automatically by the autopilot, and the CVR did not record any supervising action by the crew at that moment. The pilots were busy, making use of a laptop in the cockpit, for calculations and for obtaining data relative to the landing at and takeoff from Manaus, in the software provided by Embraer for performance and weight and balance calculations. The change to “STANDBY” occurred at the end of the period of crew silence, when the second-in-command suddenly informed the pilot-in-command, who was probably working with the RMU (Radio Management Unit), that he had finally obtained in his notebook the information which would allow them to depart from Manaus airport on the following day. The Transponder / TCAS system of the Legacy is operated through two Radio Management Units (RMU), both located on the frontal instrument panel in the cockpit.
CENIPA findings show that at 19:38, the primary radar contact was lost, and Embraer aircraft was completely out of radar screen. They say that if the transponder had been transmitting, the secondary radar coverage would have been available to the controllers. From the moment that the Transponder entered standby mode, the altitude information relative to that aircraft was being obtained by 3D primary radar equipment and not from the Transponder mode C any longer. The secondary radars are utilized by the ATC for the provision of vertical separation, and the 3D radar does not have a documentation approved by the ICAO concerning its use for traffic separation. The Brazilian ATC system does not use the 3D radar for the provision of vertical separation. It is used only for air defense purposes. When the mode C was lost, the real altitude field in radar screen started showing variable altitudes at values around 360, although the information in the data block was clearly warning that the information was coming from a 3D radar, requiring immediate actions to be taken by the controller. According to CENIPA the controller failed to act probably caused by a lack of perception or a mistaken perception of the information conveyed by the data block displayed in his radar screen.
NTSB Safety Recommendation
This topic should be amended with the final report findings, that are:
CENIPA argues in final report that it was observed that the pilots dedicated themselves to the investigation of the weight and balance software that had been inserted in the Captain’s laptop, an aspect that distracted them from the prescribed tasks of aircraft monitoring. The N600XL crew remained distracted and work while keeping their heads down for a long time.
Conflicting CENIPA and NTSB conclusions
“[...] whereas the NTSB focuses on the controllers and the ATC system, concluding that both flight crews acted properly [...] [2][6][7][47][48][49]”
The sentence is not verifiable in NTSB report and in any of the references (2,6,7,47,48,49). NTSB’s comments say that “there was no evidence of regulatory violations” which is different. The sentence should be changed to:
“[...] whereas the NTSB focuses on the controllers and the ATC system, concluding that Embraer airplane was placed on a collision course by the air traffic controllers, and that there was no evidence of regulatory violations by the crewmembers. [2][6][7][47][48][49]”
“According to Aviation Week, [...]”. That is a signed article, and then it should be written: “According to Jim Swickard in Aviation Week, [...]”.
“Aviation Week adds that "the Brazilian military operates that country's air traffic control system, conducted the investigation and authored the report.". This sentence inside “Conflicting Conclusions” must be excluded or should be in another place. It induces readers that there is a conspiracy theory of the report produced by CENIPA.
Sdruvss (
talk)
18:23, 15 December 2009 (UTC)
Crum, you are compromising the small credibility that Wikipedia have. Your strategy is demoralizing yourself. Sharkey becomes discredited when he choose to be supported by Pedicini. Now, you choose to be support by Pedicini. You choose your way. I thought you were smarter. You reveled the true story behind this article. Sdruvss ( talk) 23:02, 15 December 2009 (UTC)
Seção de Prevenção de Acidentes Aeronáuticos
DEFINIÇÃO
Prevenção de Acidentes Aeronáuticos, de Incidentes Aeronáuticos e Ocorrência de Solo é o conjunto de atividades destinadas a impedir essas ocorrências, evitando assim custos adicionais desnecessários à operação através da preservação dos recursos humanos e materiais. Os elementos que constituem a base e o objeto de toda a atividade de Prevenção de Acidentes Aeronáuticos são definidos no trinômio “homem-meio-máquina”.
PRINCÍPIOS BÁSICOS DO SIPAER
a) “Todo acidente aeronáutico pode e deve ser evitado”;
- All aviation accidents can be prevented
b) “Todo acidente aeronáutico resulta de uma seqüência de eventos, e nunca de uma causa isolada”;
- All aviation accidents result from a chain of events; never from a single isolated cause
c) “Todo acidente aeronáutico tem um precedente”;
- All aviation accidents have a precedent
d) “Prevenção de acidentes aeronáuticos é uma tarefa que requer mobilização geral”;
e) “O propósito da Prevenção de Acidentes Aeronáuticos não é restringir a atividade aérea, mas estimular o seu desenvolvimento com segurança”;
f) “Os Comandantes, Diretores e Chefes são os principais responsáveis pelas medidas de segurança”;
g) “Em prevenção de acidentes aeronáuticos não há segredos nem bandeiras”;
- There are no secrets nor borders (flags) in the prevention of aviation accidents
h) “Acusações e punições agem contra os interesses da Prevenção de Acidentes Aeronáuticos”.
- Accusations and punishments do not serve the interests of preventing aviation accidents
Crum, you are doing a very bad job with this article, making large use of partisan unreliable sources, not obeying WP content and BLB policies, intentionally messing up what primary and secondary sources are. Acting this way, covering up important issues in this accident, you collaborate to further disasters that will hurt other families. Since you speak Portuguese, it seems to me that you are one of Pedicini's sockpuppets, and then it would be clear your job here. I have these questions for you:
1. Why do you prohibit me to write in the article that FL370 in UZ6 is unusual (according to NTSB, and thousands of other sources)?
2. Why do you prohibit me to write that according to final report (and thousands of other sources) crew was distracted using a notebook when transponder turned to standby and was used in the cockpit for almost one hour?
3. Why do you prohibit me to write that according to all sources (primary, secondary, tertiary, whichever) turning off transponder makes an aircraft not being identifiable in radar screen? That is what "squawk ident" means.
4. Why do you prohibit me to write in the article that according to NTSB, the crew "acted according to appliable rules" instead of which was written here, that "they acted properly"? Which has a different meaning.
Sdruvss (
talk)
20:19, 16 December 2009 (UTC)
Dear Crum, I apologyse by my words. As you well said: "of the investigation". The subject of this article is the accident and not the "investigation". NTSB is not close to the accident, they are one step away, they are close to its investigation, what is completely different. As WP says "A secondary source contrasts with a primary source, which is an original source of the information being discussed. They are not an original source of the information of the accident. As you well said "they are equivalent to a scientist investigating a specific phenomenon", and all WP articles are based in reliable scientific research. And as WP says "Secondary sources involve generalization, analysis, synthesis, interpretation, or evaluation of the original information". This is clearly what CENIPA and NTSB do. A primary source has information and provide raw material to be analyzed. Who wants to analyze raw material? Not me, for sure, but CENIPA and NTSB do. With your good explanation about the job of CENIPA and NTSB, we both agree that facing WP policies they are secondary source. But you said "...but to interpret them properly". Who wants to interpret them? Not me. Every time I comment I quote them. I use their phrases, expressions and words. Do we have a consensus that I am not interpreting a primary source, but as a matter of fact, I am citing a reliable secondary source? We need to go deeper in this debate or it is enough? Regards, Sdruvss ( talk) 02:01, 17 December 2009 (UTC)
Sdruvss, all of these are contentious issues, and may not be analyzed or interpreted unless attributed to highly reliable secondary sources. The point, again, is not just the interpretation per se, in each case, but the very fact that it is plucked out of many other details inside the investigative reports (which are primary sources), because just mentioning a contentious issue is effectively promoting it. So if something is important, it will be picked up by a secondary source and if that source is highly reliable, as required in a contentious WP:BLP case, we can then use it. Crum375 ( talk) 14:14, 17 December 2009 (UTC)
Let me add a technical correction to your point 3 above. Although what exactly happened to the Embraer's transponder and why is unknown and open to speculation, what you say is technically incorrect. As mentioned in the article, the first event was that the transponder's "secondary signal", including the aircraft's altitude (Mode C), stopped being received by ATC. This means that ATC's radar screen reverted to displaying a "primary" target (unrelated to Wikipedia's primary source concept), which normally (in civilian radars) does not include an altitude readout. In the case of the Embraer, however, according to CENIPA and NTSB reports, ATC radar kept displaying both the primary target as well as an altitude value, apparently because the radar facility was a military installation. Some military radars (which are intended for air defense) can also display altitude for aircraft along with their position, even if their transponders are off, while civilian radars will only display the position (and speed) for no-transponder aircraft. The altitude display in such cases is of limited accuracy, since it is derived from a calculation based on the target's distance and angle above the horizon. This is mentioned in current footnote 12. Crum375 ( talk) 15:28, 17 December 2009 (UTC)
Sdruvss, a secondary signal from an aircraft's onboard transponder helps ATC identify the aircraft (which target on my screen is which aircraft?) and increases the maximum range (distance from radar antenna) at which it can be seen. A modern transponder also includes
Mode C, which provides an altitude readout. If there is no secondary signal, for example if the transponder is turned off, in standby, or malfunctioning, there will be a "primary target" visible on the radar screen while the aircraft is "in range", which for high altitudes can be well over 100 miles from the radar antenna (and there are multiple antennas). So aircraft do not automatically become "invisible", or disappear from radar screens if their transponders stop functioning; their display reverts to a primary target, normally an icon displayed on the controller's screen without an associated altitude. Except, in this particular case, because Brasilia ATC was a military facility, it had radar equipment designed for air defense purposes, which kept displaying an altitude value for the Embraer's primary target icon, even after its transponder signal was lost. This altitude value was less accurate and reliable than the Mode C derived altitude, and may have contributed to the controllers' confusion about the Embraer's altitude, and perhaps caused ATC to think that the target was still a secondary target, when in fact it became primary.
You ask why this is contentious? Because
living people are involved and there are accusations of negligence and incompetence, with 154 people dead. We therefore must strictly follow our BLP and other content policies, to maintain the highest possible quality and avoid
original research.
Crum375 (
talk)
12:53, 18 December 2009 (UTC)
Sdruvss, I am not aware of any report of any malfunction in the ATC "radar infrastructure." Could you please tell me (please quote) where in the article it currently says or implies that? Thanks, Crum375 ( talk) 19:39, 18 December 2009 (UTC)
At 16:02, seven minutes after crossing the Brasilia VOR, Embraer's transponder stopped transmitting causing ATC secondary radar to lose contact with the aircraft. Without current altitude readout from secondary radar, ATC computer system started to display primary radar unreliable altitude readout, and a symbol in the flight label that it was not working with secondary radar. At the same time, radar screen data block started displaying that the Embraer's flight plan foresaw a descent from FL370 to FL360 when passing Brasilia. It's not clear what exactly happened among ATC controllers, but investigations concluded that they were confounded by these data. Evidences gathered in the investigations demonstrated that controllers believed that Embraer was flying at FL360 after passing Brasilia, although Embraer's crew had never received any instructions to change levels.
No attempt was made by either the Embraer or Brasilia Center to contact each other from 15:51 until 16:26 when, 24 minutes after the loss of secondary radar contact, Brasilia Center called the Embraer and received no reply. During investigations, it was verified that the radio frequency provided by ATC to the crew didn't reach the point where aircraft was flying, and a suitable frequency was not commnicated to the crew, as would be expected to.
From 16:02 until 16:30 Embraer's altitude in radar screen changed very much. Starting 16:30 the Embraer's primary radar target, a label which indentify the flight in radar screen, became intermittent, and the identification disappeared completely from the radar screen by 16:38, eight minutes later. The flight became an unidentified target.
Brasilia Center unsuccessfully attempted to effect a handoff of the Embraer to Amazonic Center at 16:53, by calling the Embraer in the blind.[note 14]
Sdruvss, perhaps you missed my above question, so I'll ask it again. You said that the article says or implies that there was a "malfunction" in the "radar infrastructure". I am not aware of any report which says that. Can you please show me (please quote) where in the current article it says or implies that? Thanks, Crum375 ( talk) 20:50, 19 December 2009 (UTC)
Sdruvss, I am sorry for possibly being dense, but you say "the way it is written, it seems that the ATC lost altitude control of the Legacy because there was a malfunction in its radar infrastructure." (emphasis added) I asked you to please quote specific words which say or imply there was any kind of malfunction with the radar. If you have quoted such words which say or imply there was a malfunction, I can't find them. If you'd like to have a meaningful discussion, we need to progress step by step. If you say the current version says or implies a malfunction, you need to be able to quote the words that say or imply it. Thanks, Crum375 ( talk) 13:54, 20 December 2009 (UTC)
Sdruvss, I am not playing any game. You are criticizing the current version by saying it says or implies there was a malfunction in the radar. I can't find where it says or implies it. I ask you to please quote the specific words which say or imply the radar malfunction. If you don't provide such a quote, I can't understand or address your criticism, and we can't progress unless I understand you. Crum375 ( talk) 14:12, 20 December 2009 (UTC)
I am sorry again, but I am still not following. You said above, "the way it is written, it seems that the ATC lost altitude control of the Legacy because there was a malfunction in its radar infrastructure." (emphasis added) I asked you to please show me where it says that there was a "radar malfunction", and to please quote the specific words which say or imply there was a radar malfunction. Can you please do that? If there is a problem with the wording, we need to fix it, but we first need to understand the problem, and the first step is to quote the words in the current version which you believe say or imply "there was a malfunction in its radar infrastructure." Can you understand that without explaining yourself by presenting an exact quote, we can't proceed?
Crum375 (
talk)
15:58, 20 December 2009 (UTC)
Crum, as I said, many times, I would like to change this text:
ATC maintained normal two-way radio contact with the Embraer up until 15:51, when the last successful radio exchange with the Embraer was made on VHF frequency 125.05 MHz with Brasilia Center.[note 10] At that point the Embraer was just approaching the Brasilia VOR.[note 11] The Embraer overflew the Brasilia VOR at 15:55, four minutes later, and proceeded northwest-bound along UZ6. At 16:02, seven minutes after crossing the Brasilia VOR, secondary radar contact was lost with the Embraer, thus stopping the display of the Embraer's reported altitude (Mode C) on the controller's radar screen.[note 12]
No attempt was made by either the Embraer or Brasilia Center to contact each other from 15:51 until 16:26 when, 24 minutes after the loss of secondary radar contact,[note 13] Brasilia Center called the Embraer and received no reply.
Brasilia Center then unsuccessfully attempted to contact the Embraer six more times, between 16:30 and 16:34. At 16:30 the Embraer's primary radar target became intermittent, and disappeared completely from the radar screen by 16:38, eight minutes later. Brasilia Center unsuccessfully attempted to effect a handoff of the Embraer to Amazonic Center at 16:53, by calling the Embraer in the blind.[note 14]
To this text:
ATC maintained normal two-way radio contact with the Embraer up until 15:51, when the last successful radio exchange with the Embraer was made on VHF frequency 125.05 MHz with Brasilia Center.[note 10] At that point the Embraer was just approaching the Brasilia VOR.[note 11] The Embraer overflew the Brasilia VOR at 15:55, four minutes later, and proceeded northwest-bound along UZ6.
At 16:02, seven minutes after crossing the Brasilia VOR, Embraer's transponder stopped transmitting causing ATC secondary radar to lose contact with the aircraft. Without current altitude readout from secondary radar, ATC computer system started to display primary radar unreliable altitude readout, and a symbol in the flight label that it was not working with secondary radar. At the same time, radar screen data block started displaying that the Embraer's flight plan foresaw a descent from FL370 to FL360 when passing Brasilia. It's not clear what exactly happened among ATC controllers, but investigations concluded that they were confounded by these data. Evidences gathered in the investigations demonstrated that controllers believed that Embraer was flying at FL360 after passing Brasilia, although Embraer's crew had never received any instructions to change levels.
No attempt was made by either the Embraer or Brasilia Center to contact each other from 15:51 until 16:26 when, 24 minutes after the loss of secondary radar contact, Brasilia Center called the Embraer and received no reply. During investigations, it was verified that the radio frequency provided by ATC to the crew didn't reach the point where aircraft was flying, and a suitable frequency was not commnicated to the crew, as would be expected to.
From 16:02 until 16:30 Embraer's altitude in radar screen changed very much. Starting 16:30 the Embraer's primary radar target, a label which indentify the flight in radar screen, became intermittent, and the identification disappeared completely from the radar screen by 16:38, eight minutes later. The flight became an unidentified target.
Brasilia Center unsuccessfully attempted to effect a handoff of the Embraer to Amazonic Center at 16:53, by calling the Embraer in the blind.[note 14]
Is this clear? Do you agree? Regards. Sdruvss ( talk) 16:28, 20 December 2009 (UTC)
The reason was explained many times and must be stated here why this article is biased: this article omits intentionally in the body of the text that the current altitude of Embraer was lost in radar system because transponder was turned to standby, turning this information into a footnote. Sdruvss ( talk) 17:01, 20 December 2009 (UTC)
Crum, I said many times, and you don't read: you didn't explicitly write it. I would have to quote the intire article. I said that you omit the reasons why secondary radar data was lost. As you don't explain it, people reading the article could understand that it was a probable radar malfunction. Why do you refuse to include this little neutral piece of information into the body of the text? It seems that this is a big issue to you, is it? Sdruvss ( talk) 17:27, 20 December 2009 (UTC)
Crum, The problem is that the entire section is full of omissions, and that is why it should be rewritten. This is the point here. It omits that secondary radar has as source of altitude information the transponder signal, It omits that controller was confounded by the lack of current altitude of Embraer. It omits that crew use a notebook in cockpit by almost one hour, and they were using the notebook when transponder was turned off. Those issues are fundamental to understand the accident, are factual and not disputed by anyone.
You systematically refuse to include this neutral factual information playing all sorts of games. You make large use of selectively quoting investigation report and unreliable tertiary sources, blocking other people that want to improve this text. You became the owner of this article and use puppets to create a "community" that supports you. You make this article biased, partisan and unreliable.
But I think it is enough. It is obvious that you won't include these important factual omissions, and will run over all resources you have in your hands to achieve your goal. It has became clear your purpose with this article. Don't mind, there is lot of very interesting material here to write about WP unreliability and manipulation. This article is one more to include in your list of manipulated articles in WP. Congratulations Crum, you are becoming famous, I've read a lot about you in internet, and predictably all are verifiable. Regards
Sdruvss (
talk)
23:23, 20 December 2009 (UTC)
My contributions:
I hope they help. Regards Sdruvss ( talk) 20:42, 22 December 2009 (UTC)
This page is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Please, there are some fundamental issues not explained in this article, and could be better written in order to a non expert person, like me, understand it.
I think that those issues must be better explained here. Only experts can understand this article. Lmc9 ( talk) 00:50, 10 December 2009 (UTC)
Crum375, thank you very much for your explanations, but it seems to me that you are an “expert” reader of those huge reports, and by your high quality comments, you do not even need Wikipedia to understand this accident. It’s impossible to us (me), that just travel by planes understand those technical reports. I think that Wikipedia, as an online encyclopedia, should use a language and explanations that an “average” reader can understand it, something like “Gol flight 1907 collision for dummies”. I think, just an opinion for the guys that write here, that they should read your comments posted here and them complete the article, explaining those issues. But one thing I don’t understand in what you said (don’t think I am too stupid, but I’m not an “aircraft expert”). You said “This is done by ATC "clearing" blocks of airspace at given locations, times and altitudes for individual aircraft”. How ATC clears blocks of airspace for individual aircraft if they don’t see them in radar screen? It is said here it “disappeared completely from the radar screen”. How can they separate them without seeing them in radar screen? How ATC knows where is aircraft? How they know that the aircraft have not crashed? How they know that another aircraft that has just departed is not crossing its way? How they know that an aircraft is not in the wrong way by an instrument failure? I’ve read somewhere that ATC amends aircraft altitude all the time, asking them to climb and descend, due to winds, weather and other aircrafts that crosses their way. How they can amend altitude without knowing where is aircraft? What for radar is used? How ATC can do their work without radar? All these issues are not answered in this article. Thank you again, but I think that this article misses a lot of thinks. We read it and keep not understanding why this tragedy happened. Lmc9 ( talk) 11:37, 10 December 2009 (UTC)
Crum, there are more fundamental issues not explained in this article:
Regards, Lmc9 ( talk) 15:04, 12 December 2009 (UTC)
Crum, if you allow me, I can help you. 1) Crew awareness - CENIPA says that "(...) according to the interviews, the flight crew showed a lack of attention to the flight plan and was not able to interpret the routes and flight level changes prescribed in item 18 of their ICAO flight plan form". According "to the CVR data, the pilots did not make any comments concerning the flight management, such as, for example, the thirty-degree heading change to the left (from 006º to 336º) at the vertical of BRS VOR [Brasilia]. There were no comments about the joining of the new airway, or the possibility of a flight level change. The left turn was made automatically by the autopilot, and the CVR did not record any supervising action by the crew at that moment". And follows "When, at an interview, the crew was asked about having entered a wrong flight level for the heading they were flying, they said it is not uncommon to receive non-standard levels from the air traffic control [indeed, it is very, very uncommon as you can check by yourself, monitoring flights online]. According to them, they were flying en route, under radar contact, and did not receive any instruction from the control unit whose frequency they were monitoring. They were in accordance with the last instructions received". So, apparently they were not aware. 2) Flight plan - The file plan profile had been produced by the software of an American commercial flight planning service program considering the winds aloft available at the several WIND ALOFT charts for the FL300, FL340 and FL390. This is a long story, but making it short, CENIPA says that the navigation presented to crew was rather "unusual". Nobody is able to explain it, because those charts are valid for 12 hours, and they asked the flight plan a few days before departure. 3) Clearance - Yes, it was an ordinary clearance issued by airport towers, but has omitted "then as filed" or also could be said "limit Brasilia". 4) Transponder status not observed - Since the beginning of the recording of the Legacy CVR, the PIC and SIC were together using a notebook to calculate and obtain data of the landing and takeoff performance relative to Manaus. The crew was learning how to use it in the calculation of the aircraft weight and balance. There was a distraction from the focus of the routines relative to the monitoring of the flight progress, which made the crew direct their attention to the search and analysis of the available data relative to the remaining fuel, as well as the information contained in the software of the notebook, during a long time, possibly longer than the one that was recorded in the CVR. Between 19:00:01.5 UTC and 19:01:44.3 UTC occurs the interruption of the transponder transmission. The pilots confirmed that, at this moment, the SIC was with the laptop and worked on it alone during the two minutes; he neither passed it to the PIC, nor placed it next to the panel. The PIC, who had declared in his last interview not recalling exactly what he had been doing during this period of silence, may have been still focused on their calculation of the fuel for the departure from Manaus (seemingly) to check the current fuel status of the N600XL. The subject of the drawing of the attention of the crew to it was only solved (closing of the notebook), approximately 11 minutes after the transponder had stopped transmitting. There was a distraction from the focus of the routines relative to the monitoring of the flight progress, which made the crew direct their attention to the search and analysis of the available data relative to the remaining fuel, as well as the information contained in the software of the notebook, during a long time, possibly longer than the one that was recorded in the CVR. They didn't observed the instruments, because during this long period of time, they were working with a notebook in the cockpit, which is prohibited by many commercial airlines and even led to FAA revoke the pilots certificates in the recent incident of Northwest Airlines Flight 188. Herbmartin ( talk) 01:55, 13 December 2009 (UTC)
These are my comments about this article, and if editors allow me, I would like to edit it.
Gol Transportes Aéreos Flight 1907
This article says:
“The accident was investigated by both the Brazilian Air Force Centro de Investigação e Prevenção de Acidentes Aeronáuticos (CENIPA) and the U.S. National Transportation Safety Board (NTSB), with a final report issued on December 10, 2008. CENIPA concluded that the accident was caused by errors committed both by air traffic controllers and by the Embraer's pilots, while the NTSB determined that all pilots acted properly and were placed on a collision course by a variety of "individual and institutional" air traffic control errors”.[1][2][6][7]
The sentence “NTSB determined that all pilots acted properly” is nonspecific, cannot be verified, and was extracted of its context. Indeed, what NTSB says is that “there was no evidence of regulatory violations”. This does not mean that “pilots acted properly”. NTSB even recognizes some crew mistakes, as for instance, “[...] they did have a long term opportunity to note a nonstandard situation and request clarification or confirmation from ATC. For about 1 hour the significance of the long time period spent at a nonstandard cruise altitude for the flight direction by N600XL was not recognized”, and “Without question, N600XL proceeded for an inordinately long time without two-way communication”.
Therefore, the sentence should be corrected to:
The accident was investigated by both the Brazilian Air Force Centro de Investigação e Prevenção de Acidentes Aeronáuticos (CENIPA) and the U.S. National Transportation Safety Board (NTSB), with a final report issued on December 10, 2008. CENIPA concluded that the accident was caused by many errors committed both by air traffic controllers and by the Embraer's pilots and doesn’t point a single cause. Whereas NTSB argues that none of the errors committed by Embraer’s pilots pointed by CENIPA are evidences of regulatory violations, and they flew the route precisely as cleared and complied with all ATC instructions. NTSB concludes that accident probable cause was that aircrafts were placed on a collision course by a variety of "individual and institutional" air traffic control errors. [1][2][6][7].
Embraer aircraft and crew
The topic omits an important issue and should be amended with:
CENIPA says that Embraer’s crew had little experience of the N600XL, and had never flown together as part of the same crew. The experience of the pilot-in-command in the installed avionics of the Embraer airplane was restricted to the hours spent in the simulator, plus the 5 hours and 35 minutes of flight time prior to the accident. Even though the second-in-command was already certified in a similar Embraer model, with a total of 368 hours flown, the company decided to send him for a complete training program. [1]
Embraer flight and communication sequence
“At 16:02, seven minutes after crossing the Brasilia VOR, secondary radar contact was lost with the Embraer, thus stopping the display of the Embraer's reported altitude (Mode C) on the controller's radar screen.[note 12].”
This sentence leads the reader to understand that there was a radar failure. It is not explained that secondary radar relies on transponder signal. These are the crucial moments, fundamental to accident comprehension. It should be more detailed. I would redact the topic this way:
At 16:02, seven minutes after crossing the Brasilia VOR, secondary radar contact was lost with the Embraer, thus stopping the display of the Embraer's reported altitude (Mode C) on the controller's radar screen. According to the information available, the loss of the Transponder signal indicates that the STANDBY feature of the transponder had probably been selected.
CENIPA says that “the analysis of the CVR showed that the atmosphere in the cockpit was rather relaxed, with the pilots working with a notebook. According to the CVR data, the pilots did not make any comments concerning the flight management, such as, for example, the thirty-degree heading change to the left (from 006º to 336º) at the vertical of BRS VOR. There were no comments about the joining of the new airway, or the possibility of a flight level change. The left turn was made automatically by the autopilot, and the CVR did not record any supervising action by the crew at that moment. The pilots were busy, making use of a laptop in the cockpit, for calculations and for obtaining data relative to the landing at and takeoff from Manaus, in the software provided by Embraer for performance and weight and balance calculations. The change to “STANDBY” occurred at the end of the period of crew silence, when the second-in-command suddenly informed the pilot-in-command, who was probably working with the RMU (Radio Management Unit), that he had finally obtained in his notebook the information which would allow them to depart from Manaus airport on the following day. The Transponder / TCAS system of the Legacy is operated through two Radio Management Units (RMU), both located on the frontal instrument panel in the cockpit.
CENIPA findings show that at 19:38, the primary radar contact was lost, and Embraer aircraft was completely out of radar screen. They say that if the transponder had been transmitting, the secondary radar coverage would have been available to the controllers. From the moment that the Transponder entered standby mode, the altitude information relative to that aircraft was being obtained by 3D primary radar equipment and not from the Transponder mode C any longer. The secondary radars are utilized by the ATC for the provision of vertical separation, and the 3D radar does not have a documentation approved by the ICAO concerning its use for traffic separation. The Brazilian ATC system does not use the 3D radar for the provision of vertical separation. It is used only for air defense purposes. When the mode C was lost, the real altitude field in radar screen started showing variable altitudes at values around 360, although the information in the data block was clearly warning that the information was coming from a 3D radar, requiring immediate actions to be taken by the controller. According to CENIPA the controller failed to act probably caused by a lack of perception or a mistaken perception of the information conveyed by the data block displayed in his radar screen.
NTSB Safety Recommendation
This topic should be amended with the final report findings, that are:
CENIPA argues in final report that it was observed that the pilots dedicated themselves to the investigation of the weight and balance software that had been inserted in the Captain’s laptop, an aspect that distracted them from the prescribed tasks of aircraft monitoring. The N600XL crew remained distracted and work while keeping their heads down for a long time.
Conflicting CENIPA and NTSB conclusions
“[...] whereas the NTSB focuses on the controllers and the ATC system, concluding that both flight crews acted properly [...] [2][6][7][47][48][49]”
The sentence is not verifiable in NTSB report and in any of the references (2,6,7,47,48,49). NTSB’s comments say that “there was no evidence of regulatory violations” which is different. The sentence should be changed to:
“[...] whereas the NTSB focuses on the controllers and the ATC system, concluding that Embraer airplane was placed on a collision course by the air traffic controllers, and that there was no evidence of regulatory violations by the crewmembers. [2][6][7][47][48][49]”
“According to Aviation Week, [...]”. That is a signed article, and then it should be written: “According to Jim Swickard in Aviation Week, [...]”.
“Aviation Week adds that "the Brazilian military operates that country's air traffic control system, conducted the investigation and authored the report.". This sentence inside “Conflicting Conclusions” must be excluded or should be in another place. It induces readers that there is a conspiracy theory of the report produced by CENIPA.
Sdruvss (
talk)
18:23, 15 December 2009 (UTC)
Crum, you are compromising the small credibility that Wikipedia have. Your strategy is demoralizing yourself. Sharkey becomes discredited when he choose to be supported by Pedicini. Now, you choose to be support by Pedicini. You choose your way. I thought you were smarter. You reveled the true story behind this article. Sdruvss ( talk) 23:02, 15 December 2009 (UTC)
Seção de Prevenção de Acidentes Aeronáuticos
DEFINIÇÃO
Prevenção de Acidentes Aeronáuticos, de Incidentes Aeronáuticos e Ocorrência de Solo é o conjunto de atividades destinadas a impedir essas ocorrências, evitando assim custos adicionais desnecessários à operação através da preservação dos recursos humanos e materiais. Os elementos que constituem a base e o objeto de toda a atividade de Prevenção de Acidentes Aeronáuticos são definidos no trinômio “homem-meio-máquina”.
PRINCÍPIOS BÁSICOS DO SIPAER
a) “Todo acidente aeronáutico pode e deve ser evitado”;
- All aviation accidents can be prevented
b) “Todo acidente aeronáutico resulta de uma seqüência de eventos, e nunca de uma causa isolada”;
- All aviation accidents result from a chain of events; never from a single isolated cause
c) “Todo acidente aeronáutico tem um precedente”;
- All aviation accidents have a precedent
d) “Prevenção de acidentes aeronáuticos é uma tarefa que requer mobilização geral”;
e) “O propósito da Prevenção de Acidentes Aeronáuticos não é restringir a atividade aérea, mas estimular o seu desenvolvimento com segurança”;
f) “Os Comandantes, Diretores e Chefes são os principais responsáveis pelas medidas de segurança”;
g) “Em prevenção de acidentes aeronáuticos não há segredos nem bandeiras”;
- There are no secrets nor borders (flags) in the prevention of aviation accidents
h) “Acusações e punições agem contra os interesses da Prevenção de Acidentes Aeronáuticos”.
- Accusations and punishments do not serve the interests of preventing aviation accidents
Crum, you are doing a very bad job with this article, making large use of partisan unreliable sources, not obeying WP content and BLB policies, intentionally messing up what primary and secondary sources are. Acting this way, covering up important issues in this accident, you collaborate to further disasters that will hurt other families. Since you speak Portuguese, it seems to me that you are one of Pedicini's sockpuppets, and then it would be clear your job here. I have these questions for you:
1. Why do you prohibit me to write in the article that FL370 in UZ6 is unusual (according to NTSB, and thousands of other sources)?
2. Why do you prohibit me to write that according to final report (and thousands of other sources) crew was distracted using a notebook when transponder turned to standby and was used in the cockpit for almost one hour?
3. Why do you prohibit me to write that according to all sources (primary, secondary, tertiary, whichever) turning off transponder makes an aircraft not being identifiable in radar screen? That is what "squawk ident" means.
4. Why do you prohibit me to write in the article that according to NTSB, the crew "acted according to appliable rules" instead of which was written here, that "they acted properly"? Which has a different meaning.
Sdruvss (
talk)
20:19, 16 December 2009 (UTC)
Dear Crum, I apologyse by my words. As you well said: "of the investigation". The subject of this article is the accident and not the "investigation". NTSB is not close to the accident, they are one step away, they are close to its investigation, what is completely different. As WP says "A secondary source contrasts with a primary source, which is an original source of the information being discussed. They are not an original source of the information of the accident. As you well said "they are equivalent to a scientist investigating a specific phenomenon", and all WP articles are based in reliable scientific research. And as WP says "Secondary sources involve generalization, analysis, synthesis, interpretation, or evaluation of the original information". This is clearly what CENIPA and NTSB do. A primary source has information and provide raw material to be analyzed. Who wants to analyze raw material? Not me, for sure, but CENIPA and NTSB do. With your good explanation about the job of CENIPA and NTSB, we both agree that facing WP policies they are secondary source. But you said "...but to interpret them properly". Who wants to interpret them? Not me. Every time I comment I quote them. I use their phrases, expressions and words. Do we have a consensus that I am not interpreting a primary source, but as a matter of fact, I am citing a reliable secondary source? We need to go deeper in this debate or it is enough? Regards, Sdruvss ( talk) 02:01, 17 December 2009 (UTC)
Sdruvss, all of these are contentious issues, and may not be analyzed or interpreted unless attributed to highly reliable secondary sources. The point, again, is not just the interpretation per se, in each case, but the very fact that it is plucked out of many other details inside the investigative reports (which are primary sources), because just mentioning a contentious issue is effectively promoting it. So if something is important, it will be picked up by a secondary source and if that source is highly reliable, as required in a contentious WP:BLP case, we can then use it. Crum375 ( talk) 14:14, 17 December 2009 (UTC)
Let me add a technical correction to your point 3 above. Although what exactly happened to the Embraer's transponder and why is unknown and open to speculation, what you say is technically incorrect. As mentioned in the article, the first event was that the transponder's "secondary signal", including the aircraft's altitude (Mode C), stopped being received by ATC. This means that ATC's radar screen reverted to displaying a "primary" target (unrelated to Wikipedia's primary source concept), which normally (in civilian radars) does not include an altitude readout. In the case of the Embraer, however, according to CENIPA and NTSB reports, ATC radar kept displaying both the primary target as well as an altitude value, apparently because the radar facility was a military installation. Some military radars (which are intended for air defense) can also display altitude for aircraft along with their position, even if their transponders are off, while civilian radars will only display the position (and speed) for no-transponder aircraft. The altitude display in such cases is of limited accuracy, since it is derived from a calculation based on the target's distance and angle above the horizon. This is mentioned in current footnote 12. Crum375 ( talk) 15:28, 17 December 2009 (UTC)
Sdruvss, a secondary signal from an aircraft's onboard transponder helps ATC identify the aircraft (which target on my screen is which aircraft?) and increases the maximum range (distance from radar antenna) at which it can be seen. A modern transponder also includes
Mode C, which provides an altitude readout. If there is no secondary signal, for example if the transponder is turned off, in standby, or malfunctioning, there will be a "primary target" visible on the radar screen while the aircraft is "in range", which for high altitudes can be well over 100 miles from the radar antenna (and there are multiple antennas). So aircraft do not automatically become "invisible", or disappear from radar screens if their transponders stop functioning; their display reverts to a primary target, normally an icon displayed on the controller's screen without an associated altitude. Except, in this particular case, because Brasilia ATC was a military facility, it had radar equipment designed for air defense purposes, which kept displaying an altitude value for the Embraer's primary target icon, even after its transponder signal was lost. This altitude value was less accurate and reliable than the Mode C derived altitude, and may have contributed to the controllers' confusion about the Embraer's altitude, and perhaps caused ATC to think that the target was still a secondary target, when in fact it became primary.
You ask why this is contentious? Because
living people are involved and there are accusations of negligence and incompetence, with 154 people dead. We therefore must strictly follow our BLP and other content policies, to maintain the highest possible quality and avoid
original research.
Crum375 (
talk)
12:53, 18 December 2009 (UTC)
Sdruvss, I am not aware of any report of any malfunction in the ATC "radar infrastructure." Could you please tell me (please quote) where in the article it currently says or implies that? Thanks, Crum375 ( talk) 19:39, 18 December 2009 (UTC)
At 16:02, seven minutes after crossing the Brasilia VOR, Embraer's transponder stopped transmitting causing ATC secondary radar to lose contact with the aircraft. Without current altitude readout from secondary radar, ATC computer system started to display primary radar unreliable altitude readout, and a symbol in the flight label that it was not working with secondary radar. At the same time, radar screen data block started displaying that the Embraer's flight plan foresaw a descent from FL370 to FL360 when passing Brasilia. It's not clear what exactly happened among ATC controllers, but investigations concluded that they were confounded by these data. Evidences gathered in the investigations demonstrated that controllers believed that Embraer was flying at FL360 after passing Brasilia, although Embraer's crew had never received any instructions to change levels.
No attempt was made by either the Embraer or Brasilia Center to contact each other from 15:51 until 16:26 when, 24 minutes after the loss of secondary radar contact, Brasilia Center called the Embraer and received no reply. During investigations, it was verified that the radio frequency provided by ATC to the crew didn't reach the point where aircraft was flying, and a suitable frequency was not commnicated to the crew, as would be expected to.
From 16:02 until 16:30 Embraer's altitude in radar screen changed very much. Starting 16:30 the Embraer's primary radar target, a label which indentify the flight in radar screen, became intermittent, and the identification disappeared completely from the radar screen by 16:38, eight minutes later. The flight became an unidentified target.
Brasilia Center unsuccessfully attempted to effect a handoff of the Embraer to Amazonic Center at 16:53, by calling the Embraer in the blind.[note 14]
Sdruvss, perhaps you missed my above question, so I'll ask it again. You said that the article says or implies that there was a "malfunction" in the "radar infrastructure". I am not aware of any report which says that. Can you please show me (please quote) where in the current article it says or implies that? Thanks, Crum375 ( talk) 20:50, 19 December 2009 (UTC)
Sdruvss, I am sorry for possibly being dense, but you say "the way it is written, it seems that the ATC lost altitude control of the Legacy because there was a malfunction in its radar infrastructure." (emphasis added) I asked you to please quote specific words which say or imply there was any kind of malfunction with the radar. If you have quoted such words which say or imply there was a malfunction, I can't find them. If you'd like to have a meaningful discussion, we need to progress step by step. If you say the current version says or implies a malfunction, you need to be able to quote the words that say or imply it. Thanks, Crum375 ( talk) 13:54, 20 December 2009 (UTC)
Sdruvss, I am not playing any game. You are criticizing the current version by saying it says or implies there was a malfunction in the radar. I can't find where it says or implies it. I ask you to please quote the specific words which say or imply the radar malfunction. If you don't provide such a quote, I can't understand or address your criticism, and we can't progress unless I understand you. Crum375 ( talk) 14:12, 20 December 2009 (UTC)
I am sorry again, but I am still not following. You said above, "the way it is written, it seems that the ATC lost altitude control of the Legacy because there was a malfunction in its radar infrastructure." (emphasis added) I asked you to please show me where it says that there was a "radar malfunction", and to please quote the specific words which say or imply there was a radar malfunction. Can you please do that? If there is a problem with the wording, we need to fix it, but we first need to understand the problem, and the first step is to quote the words in the current version which you believe say or imply "there was a malfunction in its radar infrastructure." Can you understand that without explaining yourself by presenting an exact quote, we can't proceed?
Crum375 (
talk)
15:58, 20 December 2009 (UTC)
Crum, as I said, many times, I would like to change this text:
ATC maintained normal two-way radio contact with the Embraer up until 15:51, when the last successful radio exchange with the Embraer was made on VHF frequency 125.05 MHz with Brasilia Center.[note 10] At that point the Embraer was just approaching the Brasilia VOR.[note 11] The Embraer overflew the Brasilia VOR at 15:55, four minutes later, and proceeded northwest-bound along UZ6. At 16:02, seven minutes after crossing the Brasilia VOR, secondary radar contact was lost with the Embraer, thus stopping the display of the Embraer's reported altitude (Mode C) on the controller's radar screen.[note 12]
No attempt was made by either the Embraer or Brasilia Center to contact each other from 15:51 until 16:26 when, 24 minutes after the loss of secondary radar contact,[note 13] Brasilia Center called the Embraer and received no reply.
Brasilia Center then unsuccessfully attempted to contact the Embraer six more times, between 16:30 and 16:34. At 16:30 the Embraer's primary radar target became intermittent, and disappeared completely from the radar screen by 16:38, eight minutes later. Brasilia Center unsuccessfully attempted to effect a handoff of the Embraer to Amazonic Center at 16:53, by calling the Embraer in the blind.[note 14]
To this text:
ATC maintained normal two-way radio contact with the Embraer up until 15:51, when the last successful radio exchange with the Embraer was made on VHF frequency 125.05 MHz with Brasilia Center.[note 10] At that point the Embraer was just approaching the Brasilia VOR.[note 11] The Embraer overflew the Brasilia VOR at 15:55, four minutes later, and proceeded northwest-bound along UZ6.
At 16:02, seven minutes after crossing the Brasilia VOR, Embraer's transponder stopped transmitting causing ATC secondary radar to lose contact with the aircraft. Without current altitude readout from secondary radar, ATC computer system started to display primary radar unreliable altitude readout, and a symbol in the flight label that it was not working with secondary radar. At the same time, radar screen data block started displaying that the Embraer's flight plan foresaw a descent from FL370 to FL360 when passing Brasilia. It's not clear what exactly happened among ATC controllers, but investigations concluded that they were confounded by these data. Evidences gathered in the investigations demonstrated that controllers believed that Embraer was flying at FL360 after passing Brasilia, although Embraer's crew had never received any instructions to change levels.
No attempt was made by either the Embraer or Brasilia Center to contact each other from 15:51 until 16:26 when, 24 minutes after the loss of secondary radar contact, Brasilia Center called the Embraer and received no reply. During investigations, it was verified that the radio frequency provided by ATC to the crew didn't reach the point where aircraft was flying, and a suitable frequency was not commnicated to the crew, as would be expected to.
From 16:02 until 16:30 Embraer's altitude in radar screen changed very much. Starting 16:30 the Embraer's primary radar target, a label which indentify the flight in radar screen, became intermittent, and the identification disappeared completely from the radar screen by 16:38, eight minutes later. The flight became an unidentified target.
Brasilia Center unsuccessfully attempted to effect a handoff of the Embraer to Amazonic Center at 16:53, by calling the Embraer in the blind.[note 14]
Is this clear? Do you agree? Regards. Sdruvss ( talk) 16:28, 20 December 2009 (UTC)
The reason was explained many times and must be stated here why this article is biased: this article omits intentionally in the body of the text that the current altitude of Embraer was lost in radar system because transponder was turned to standby, turning this information into a footnote. Sdruvss ( talk) 17:01, 20 December 2009 (UTC)
Crum, I said many times, and you don't read: you didn't explicitly write it. I would have to quote the intire article. I said that you omit the reasons why secondary radar data was lost. As you don't explain it, people reading the article could understand that it was a probable radar malfunction. Why do you refuse to include this little neutral piece of information into the body of the text? It seems that this is a big issue to you, is it? Sdruvss ( talk) 17:27, 20 December 2009 (UTC)
Crum, The problem is that the entire section is full of omissions, and that is why it should be rewritten. This is the point here. It omits that secondary radar has as source of altitude information the transponder signal, It omits that controller was confounded by the lack of current altitude of Embraer. It omits that crew use a notebook in cockpit by almost one hour, and they were using the notebook when transponder was turned off. Those issues are fundamental to understand the accident, are factual and not disputed by anyone.
You systematically refuse to include this neutral factual information playing all sorts of games. You make large use of selectively quoting investigation report and unreliable tertiary sources, blocking other people that want to improve this text. You became the owner of this article and use puppets to create a "community" that supports you. You make this article biased, partisan and unreliable.
But I think it is enough. It is obvious that you won't include these important factual omissions, and will run over all resources you have in your hands to achieve your goal. It has became clear your purpose with this article. Don't mind, there is lot of very interesting material here to write about WP unreliability and manipulation. This article is one more to include in your list of manipulated articles in WP. Congratulations Crum, you are becoming famous, I've read a lot about you in internet, and predictably all are verifiable. Regards
Sdruvss (
talk)
23:23, 20 December 2009 (UTC)
My contributions:
I hope they help. Regards Sdruvss ( talk) 20:42, 22 December 2009 (UTC)