Mid-air collision over Brasil
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TCAS does not need any line of sight with ground equipment. It only looks at other Mode C transponders and gives climb or descent commands in coordination with the other TCAS. My question was if they lost Mode C with Legacy and also VHF com maybe they were in one of their blind spots because of line of sight not allowing either to work. As far as the temperature of the transponder equipment I agree most equipment would probably be in the pressurized climate controlled part of the aircraft but skin temperatures and coax to antennas have to be eventually routed to an external antenna which may be affected by cold temperatures. If on their next flight they had the same problem then we would know what caused the failure. If it didn't happen it could be just the conditions not being the same.
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Okay, let's assume for the sake of argument the "Worst Case" scenario for everyone involved, based on the evidence "leaked". This is far from factual -- just what the "best possible case" the FP would have:
Rookie FO on his first flight with the company, and with his bosses in back, fumbles when told to ident, and somehow shuts off the transponder.
ATC is watching the football match, and doesn't notice the transponder problem.
Both sides make a halfhearted attempt to establish radio contact.
After impact, when the Legacy crew turns to squawk 7700, one of them says "Oh ****, the transponder's in standby", and turns it back on.
So, if this were the case they had, who would get what out of it?
In any reasonable country, even this scenario wouldn't result in criminal charges, except perhaps to whoever setup the policies by which ATCs operate (and even in reasonable countries, those guys are well protected): there's no clear reason why the transponder was turned off, and no other evidence to suggest this was a conscious error, or one that occurred through willful incompetence.
Aviation Safety is severely damaged in Brazil: if you're gonna make a mistake and turn something off, better start with the CVR; and with a couple of controllers in jail, you think any future ATC tapes are going to survive without damage?
On the other hand, the provincial FP running the case becomes a nationally known figure. Perhaps noting how Tsolakis flight, catapulted to regional fame as the head of the Greek investigatory board inquiring into the Helios tragedy, the Brazilian Federal Police are making sure they be the focus of attention, not the investigators.
And that's the "Best Case" scenario, assuming the absolute worst of the pilots and controllers.
In short, it's a political game with very few winners, and millions of losers.
Rookie FO on his first flight with the company, and with his bosses in back, fumbles when told to ident, and somehow shuts off the transponder.
ATC is watching the football match, and doesn't notice the transponder problem.
Both sides make a halfhearted attempt to establish radio contact.
After impact, when the Legacy crew turns to squawk 7700, one of them says "Oh ****, the transponder's in standby", and turns it back on.
So, if this were the case they had, who would get what out of it?
In any reasonable country, even this scenario wouldn't result in criminal charges, except perhaps to whoever setup the policies by which ATCs operate (and even in reasonable countries, those guys are well protected): there's no clear reason why the transponder was turned off, and no other evidence to suggest this was a conscious error, or one that occurred through willful incompetence.
Aviation Safety is severely damaged in Brazil: if you're gonna make a mistake and turn something off, better start with the CVR; and with a couple of controllers in jail, you think any future ATC tapes are going to survive without damage?
On the other hand, the provincial FP running the case becomes a nationally known figure. Perhaps noting how Tsolakis flight, catapulted to regional fame as the head of the Greek investigatory board inquiring into the Helios tragedy, the Brazilian Federal Police are making sure they be the focus of attention, not the investigators.
And that's the "Best Case" scenario, assuming the absolute worst of the pilots and controllers.
In short, it's a political game with very few winners, and millions of losers.
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http://video.msn.com/v/us/fv/msnbc/f...id/3032633/&fg=
8 minute, 42 second interview on the "Today Show" of both Joe & Jan (and their lawyer), by Matt Lauer. Very interesting. It's in English.
8 minute, 42 second interview on the "Today Show" of both Joe & Jan (and their lawyer), by Matt Lauer. Very interesting. It's in English.
Can't play the clip. Once past the ads, robot woman announces that "the clip is being prepared in a format that will be compatible with your system..."
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regarding the transponder.
if you had made 12 attempts to contact atc via vhf radio and didn't get hold of anyone, wouldn't you at least think about selecting 7600 in the transponder...mind you I am not saying to do it just yet, but at least think of it?
honestly, if I hadn't had any radio transmissions in a certain amount of time, I would look at my tcas to see if there were any other planes nearby for a relay or at least a radio check.
and when looking at my tcas display ( unless it is one of the real small cheap ones) I would certainly see any warning that it wasn't working because my transponder was off...
just questions and not judgements yet.
pilots do have to think and question and consider situations.
if you had made 12 attempts to contact atc via vhf radio and didn't get hold of anyone, wouldn't you at least think about selecting 7600 in the transponder...mind you I am not saying to do it just yet, but at least think of it?
honestly, if I hadn't had any radio transmissions in a certain amount of time, I would look at my tcas to see if there were any other planes nearby for a relay or at least a radio check.
and when looking at my tcas display ( unless it is one of the real small cheap ones) I would certainly see any warning that it wasn't working because my transponder was off...
just questions and not judgements yet.
pilots do have to think and question and consider situations.
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jondc9, the issue for me is not really about humans failing to notice their Xponder was off or on SBY for so long, , but the sofware trap that caused the system to shut down that way, and the HMI design that prevented the crew from noticing it.
Because it happened before ( in Switserland and France recently, both involving E145 with Primus ), and so, most probably, it will happen again .
The idiocy of this is that by switching itself off, it also disable ( ACAS) as well.
So the end result of this is depriving you in one go of your 2 main anticollison systems : ATC and ACAS.
This is half of the cause of this collision. The other half is on the ground and there apparently, also caused by 2 software traps that led the controllers to beleive the aircrfat was not at the altitude he actually was .
I think we should far more focus on HMI and computers/man decisions processes integration than about blaming their operators .
But this is far less popular.
Because it happened before ( in Switserland and France recently, both involving E145 with Primus ), and so, most probably, it will happen again .
The idiocy of this is that by switching itself off, it also disable ( ACAS) as well.
So the end result of this is depriving you in one go of your 2 main anticollison systems : ATC and ACAS.
This is half of the cause of this collision. The other half is on the ground and there apparently, also caused by 2 software traps that led the controllers to beleive the aircrfat was not at the altitude he actually was .
I think we should far more focus on HMI and computers/man decisions processes integration than about blaming their operators .
But this is far less popular.
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Making numerous attempts at communications down there isn't uncommon so squacking 7600 never occured to me because usually the radar wasn't available either. I routinely found that places as close as Kingston seemed to make it a game to see how many times you would call them without them answering. I finally would just make two calls then one in the blind giving my position and ETA. This always got a response because it was treating them like a 3rd world country.
Pilots Say They Flew Assigned Altitude Before Crash (Update1)
By John Hughes
Dec. 15 (Bloomberg) -- Two U.S. pilots said they were flying at their assigned altitude of 37,000 feet when their small jet collided with a Brazilian airliner in September, killing 154 people in that country's worst aviation accident.
``We cannot leave our altitude without instructions from air-traffic control,'' pilot Jan Paladino said on the ``Today Show'' on NBC-TV. ``We were doing exactly what we were supposed to be doing.''
By John Hughes
Dec. 15 (Bloomberg) -- Two U.S. pilots said they were flying at their assigned altitude of 37,000 feet when their small jet collided with a Brazilian airliner in September, killing 154 people in that country's worst aviation accident.
``We cannot leave our altitude without instructions from air-traffic control,'' pilot Jan Paladino said on the ``Today Show'' on NBC-TV. ``We were doing exactly what we were supposed to be doing.''
The accident was a tragedy, but it is a miracle that one plane landed safely.
I'm probably naively repeating much of what has been said already, but my best wishes go out to everyone involved.
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Be sure you have Windows Media Player version 9 or later.
Not available in stores.
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A generally good interview on Today, but does anybody know where that animation came from? It seems more than a bit sloppy to portray the Legacy losing the entire port side of the horizontal stab and entire winglet when the still photo clearly showed the damage was not that severe. One could overlook the winglet, but if they had lost that much of the stab one might conclude they would have suffered the same unfortunate fate as the Gol 737.
It was also interesting to hear that due to translation issues the reports that made it appear they were formally "charged" just before their release also seem to have been somewhat exaggerated.
Best of luck to you, guys, we're pulling for you.
It was also interesting to hear that due to translation issues the reports that made it appear they were formally "charged" just before their release also seem to have been somewhat exaggerated.
Best of luck to you, guys, we're pulling for you.
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ATC Watcher/jondc9
ATC
I do not believe you should lump together "ATC and (T)ACAS" as the two primary anti-collision systems. This , of course, is not true. They are not co-equals. ATC is the primary collision avoidance system ....that is its primary role, ie, separation.... other than eyeballs (which is interesting since there has been no discussion of looking out the window...have we given this up because of closure rates or other factors for all aircraft at flight levels above 180 ?)
what is becoming more and more obvious......
ATC cleared both aircraft to the same level without proper coordination between adjoining sectors. Through inadvertence, complicated by possible flaws in its procedures, equipment performance or design, ATC was neither able to recognize the nature of the situation that was unfolding and communicate this to other sectors nor communicate with the Legacy to issue an appropriate clearance or confirm its level. Contributing factors were poor communictions coverage and failure or improper operation of the transponder aboard the Legacy.
jondc9
your characterization of the twelve calls as being sufficient cause to select
7600 does not consider that those calls occurred in 4 minute period(not very long in this environment) followed by what probably appeared to them as a response from ATC to their calls (which, in fact, appears to have been a blind call from ATC) requesting that they change frequency. I suggest that the lost-comm situation began following the crew's subsequent unsuccessful attempts to contact ATC....just two minutes or so before impact. At this point the ATC controller should have been on the horn to the next sector controller (who was in contact with GOL) advising of the NORDO Legacy at an unconfirmed FL360. Since the collision occurred at or near the sector boundary, it will be interesting to learn whether the Brasilia controller had the GOL flight on his display and for how long.
I do not believe you should lump together "ATC and (T)ACAS" as the two primary anti-collision systems. This , of course, is not true. They are not co-equals. ATC is the primary collision avoidance system ....that is its primary role, ie, separation.... other than eyeballs (which is interesting since there has been no discussion of looking out the window...have we given this up because of closure rates or other factors for all aircraft at flight levels above 180 ?)
what is becoming more and more obvious......
ATC cleared both aircraft to the same level without proper coordination between adjoining sectors. Through inadvertence, complicated by possible flaws in its procedures, equipment performance or design, ATC was neither able to recognize the nature of the situation that was unfolding and communicate this to other sectors nor communicate with the Legacy to issue an appropriate clearance or confirm its level. Contributing factors were poor communictions coverage and failure or improper operation of the transponder aboard the Legacy.
jondc9
your characterization of the twelve calls as being sufficient cause to select
7600 does not consider that those calls occurred in 4 minute period(not very long in this environment) followed by what probably appeared to them as a response from ATC to their calls (which, in fact, appears to have been a blind call from ATC) requesting that they change frequency. I suggest that the lost-comm situation began following the crew's subsequent unsuccessful attempts to contact ATC....just two minutes or so before impact. At this point the ATC controller should have been on the horn to the next sector controller (who was in contact with GOL) advising of the NORDO Legacy at an unconfirmed FL360. Since the collision occurred at or near the sector boundary, it will be interesting to learn whether the Brasilia controller had the GOL flight on his display and for how long.
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but thinking about 7600 on the transponder MIGHT, key word MIGHT, have made the legacy pilots look at the transponder and see if there was a reply light illuminating at regular intervals.
if you have charts for brazil, does the airway/jet route show "communications gap" for the area involved?
also, did the legacy pilots attempt contact on all comm radios? some comm radios are wired to the top antenna, some to the bottom and sometimes (not always) this might make a difference.
if you have charts for brazil, does the airway/jet route show "communications gap" for the area involved?
also, did the legacy pilots attempt contact on all comm radios? some comm radios are wired to the top antenna, some to the bottom and sometimes (not always) this might make a difference.
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A310 driver
You read my post too fast I think , look again : I did not say that ATC and ACAS were " primary" means of separation, but " main" means. Because I agree with you, in IFR , the primary means of anti-collision is ATC, and ACAS is the ultimate last minute one. (In between there is visual aquisition) .
The rest of your post is fully correct, except that the communication problems were not between adjacent sectors, ( i.e sectors within a same unit, seing teh same radar picure ) but adjacent centres , i.e 3 different ATC units located hunderds of miles appart and using diferent ATC systems and radars.
From what it transpires now, Manaus expected the legacy a 360 and since they never saw it coming as the Xponder was not on, and it did not call already , they had little reason to " move" the 737 out of the airway . What happened in Campos and Brasilia is less clear.The transcript of the coordination between the two will probably shed some light when we see it.
The Brasilia ATC system showed the legacy at 360 ( while it was in fact at 370) that we know, and we know why.
I do not think Brasilia had the 737 on radar nor on R/T contact. Again the radar recording of Brasilia will show this when it will become public.
( and check your PM)
The rest of your post is fully correct, except that the communication problems were not between adjacent sectors, ( i.e sectors within a same unit, seing teh same radar picure ) but adjacent centres , i.e 3 different ATC units located hunderds of miles appart and using diferent ATC systems and radars.
From what it transpires now, Manaus expected the legacy a 360 and since they never saw it coming as the Xponder was not on, and it did not call already , they had little reason to " move" the 737 out of the airway . What happened in Campos and Brasilia is less clear.The transcript of the coordination between the two will probably shed some light when we see it.
The Brasilia ATC system showed the legacy at 360 ( while it was in fact at 370) that we know, and we know why.
I do not think Brasilia had the 737 on radar nor on R/T contact. Again the radar recording of Brasilia will show this when it will become public.
( and check your PM)
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If Brazil has a radar facility that receives Mode C transponder data why wouldn't they have a VHF transceiver at the same site so they could talk to them since they both operate with line of sight frequencies? Are they sure the transponder failed on Legacy when ATC lost it or were they out of range in one of their blind areas. Since ATC didn't question the loss of Mode C they must have experienced it routinely so didn't question them. Why would software in their radar room automatically display them at their flight planned altitude because they lost Mode C? The shift change might have contributed to why them reporting in at FL370 and later displaying FL360 didn't get picked up.
I think Brazil has to fix their ATC problems quickly because blaming the American pilots isn't going to bail them out.
I think Brazil has to fix their ATC problems quickly because blaming the American pilots isn't going to bail them out.
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way back when...
in the US atc was required to point out jet traffic to other traffic as a matter of course...
even if seperated by altitude or heading.
and if brazil atc had done this just as a matter of course, eg: GOL AIR, JET TRAFFIC 12 o'clock, radar shows at FL360
at least GOL could have been looking...might have then mentioned not seen on TCAS (we mention that here in the states all the time)
the more technology becomes involved and the more good people become less involved you will get problems.
in the US atc was required to point out jet traffic to other traffic as a matter of course...
even if seperated by altitude or heading.
and if brazil atc had done this just as a matter of course, eg: GOL AIR, JET TRAFFIC 12 o'clock, radar shows at FL360
at least GOL could have been looking...might have then mentioned not seen on TCAS (we mention that here in the states all the time)
the more technology becomes involved and the more good people become less involved you will get problems.
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Collision was inside Manaus (Cindacta 4) covering.
(this should answer the question of A310driver).
In another news was said that Gol received radio transmisions from Brasilia ATC to the Legacy, and the captain Decio Chaves listened them.
http://g1.globo.com/Noticias/Brasil/...98-295,00.html
Last edited by caos; 17th Dec 2006 at 01:04. Reason: add info
foxtrot xray
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Atc Watcher
Regarding your post above, you are technically correct regarding center/sector boundaries.
However,there is no functional difference between a sector boundary and a center boundary within the same country in a modern ATC system even though the physical facilities of the centers may be hundreds of miles apart. When I transit the Cleveland Center / New York Center boundary or the Cleveland / Chicago or the NY/Washington Center boundary yes the controllers are hundreds of miles apart but the radar and communications systems are integrated such that there is no practical difference from being handed off to a controller working another sector within a center boundary. What you imply may be true crossing an international center boundary, like Cleveland/Toronto or Miami/Havana but has no relevance in this discussion as it occurred wholly within the Brazil domestic system.
However,there is no functional difference between a sector boundary and a center boundary within the same country in a modern ATC system even though the physical facilities of the centers may be hundreds of miles apart. When I transit the Cleveland Center / New York Center boundary or the Cleveland / Chicago or the NY/Washington Center boundary yes the controllers are hundreds of miles apart but the radar and communications systems are integrated such that there is no practical difference from being handed off to a controller working another sector within a center boundary. What you imply may be true crossing an international center boundary, like Cleveland/Toronto or Miami/Havana but has no relevance in this discussion as it occurred wholly within the Brazil domestic system.
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There is a long interview with Lepore and Paladino (and their lawyer, Torricella) in the Sunday Folha. The online version is more complete than the printed version, and can be found (in Portuguese translation) at
http://www1.folha.uol.com.br/folha/c...5u129463.shtml
Principal items of interest here are:
1) The radio was functioning just fine. Paladino says, "We received transmissions in Portuguese from Brasilia during the whole flight." He also says that when he did talk to the controller in Brasilia, [IIRC, a few minutes before the collision], to get the frequency in Manaus, there was "no urgency" in the controller's voice.
2) Asked about why they didn't set the transponder to code 7600 [ATC has said they should have], registering communications difficulties, Paladino again says, "7600 isn't for difficulty in talking to the control center, it's for equipment failure. That wasn't the case. The radio was perfectly fine. What we we have to do, in these cases, is search for another frequency, more appropriate for the route, which is what I did."
3) Police have claimed there's a dialogue between the pilots recognizing that transponder was turned off. Lawyer (who reporter describes as being like "a lioness defending her cubs") wouldn't let them answer that.
4) Lepore claimed that "It happens all the time, that you have a flight plan at one altitude and you are authorized to fly at another. Let's say it happens 99% of the time."
5) Something online, not in the printed newspaper, is about the Legacy not descending to 360 over Brasilia. Paladino says, "We're not expected to contract the control tower on flying over Brasilia". The lawyer, Torricella, says, "The regulation for when you're under radar vigilance is that the control tower is who defines the rules and altitudes is the contol center. The law is clear."
6) The pilots indicated they were quite familiar with the Legacy; Lepore had 20 hours of simulator and a lot of time in very similar aircraft; Paladino had flown a lot as commandant of an Embraer 145, an exact copy of the Legacy.
----
It's an honest interview. The reporter, Eliane Cantanhêde, asks the tough questions and they answer, except that the lawyer won't let them reproduce dialogues for which the police are withholding the transcripts. This was in contrast to the travesty of the interview with the controllers in Época magazine, in which they didn't even give their names, and got only soft questions, with Época tiptoeing around the real issues.
Note that the interview was taped in English, transcribed to Portuguese, and the taped destroyed, presumably to keep lawyers from playing the word games they so love. Quotes above are my own translations back to English, and certainly vary from what was actually said.
They are only unconvincing when Cantanhêde asks what they think of the Brazilian press coverage, and all three respond diplomatically. Though the less Portuguese one speaks, the better the coverage appears. The accusations against the pilots have been compared by others to the worst excesses of the Brazilian media.
http://www1.folha.uol.com.br/folha/c...5u129463.shtml
Principal items of interest here are:
1) The radio was functioning just fine. Paladino says, "We received transmissions in Portuguese from Brasilia during the whole flight." He also says that when he did talk to the controller in Brasilia, [IIRC, a few minutes before the collision], to get the frequency in Manaus, there was "no urgency" in the controller's voice.
2) Asked about why they didn't set the transponder to code 7600 [ATC has said they should have], registering communications difficulties, Paladino again says, "7600 isn't for difficulty in talking to the control center, it's for equipment failure. That wasn't the case. The radio was perfectly fine. What we we have to do, in these cases, is search for another frequency, more appropriate for the route, which is what I did."
3) Police have claimed there's a dialogue between the pilots recognizing that transponder was turned off. Lawyer (who reporter describes as being like "a lioness defending her cubs") wouldn't let them answer that.
4) Lepore claimed that "It happens all the time, that you have a flight plan at one altitude and you are authorized to fly at another. Let's say it happens 99% of the time."
5) Something online, not in the printed newspaper, is about the Legacy not descending to 360 over Brasilia. Paladino says, "We're not expected to contract the control tower on flying over Brasilia". The lawyer, Torricella, says, "The regulation for when you're under radar vigilance is that the control tower is who defines the rules and altitudes is the contol center. The law is clear."
6) The pilots indicated they were quite familiar with the Legacy; Lepore had 20 hours of simulator and a lot of time in very similar aircraft; Paladino had flown a lot as commandant of an Embraer 145, an exact copy of the Legacy.
----
It's an honest interview. The reporter, Eliane Cantanhêde, asks the tough questions and they answer, except that the lawyer won't let them reproduce dialogues for which the police are withholding the transcripts. This was in contrast to the travesty of the interview with the controllers in Época magazine, in which they didn't even give their names, and got only soft questions, with Época tiptoeing around the real issues.
Note that the interview was taped in English, transcribed to Portuguese, and the taped destroyed, presumably to keep lawyers from playing the word games they so love. Quotes above are my own translations back to English, and certainly vary from what was actually said.
They are only unconvincing when Cantanhêde asks what they think of the Brazilian press coverage, and all three respond diplomatically. Though the less Portuguese one speaks, the better the coverage appears. The accusations against the pilots have been compared by others to the worst excesses of the Brazilian media.
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A310driver
...the radar and communications systems are integrated such that there is no practical difference from being handed off to a controller working another sector within a center boundary. What you imply ..... has no relevance in this discussion as it occurred wholly within the Brazil domestic system.
I do not think this whole integration apply for Brazil, but you can correct me if you have the facts of course.
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well, the feeling and meaning is odd in the above interview.
IF the radios were working "just fine" then why couldn't they talk to anyone? even if given the wrong frequency, you go back to the good one, or look at your chart and find the nearest ATC facility and call them and when in doubt, 121.5mhz.
and according to the US AIM, check out sections 6-4-1 (2,3), : if an aircraft with a coded radar beacon transponder experiences a loss of two-way radio capability, the pilot should adjust the transponder to reply on Mode A/3 , Code 7600.
this does not say: equipment faliure.
it goes on to encourge use of 121.5mhz and ARINC and listening on VOR's.
IF the radios were working "just fine" then why couldn't they talk to anyone? even if given the wrong frequency, you go back to the good one, or look at your chart and find the nearest ATC facility and call them and when in doubt, 121.5mhz.
and according to the US AIM, check out sections 6-4-1 (2,3), : if an aircraft with a coded radar beacon transponder experiences a loss of two-way radio capability, the pilot should adjust the transponder to reply on Mode A/3 , Code 7600.
this does not say: equipment faliure.
it goes on to encourge use of 121.5mhz and ARINC and listening on VOR's.