baron95
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ATC At Fault In Gol 737-Legacy Collision In Brazil

Tue Jan 23, 2007 4:24 pm

http://www.avweb.com/avwebflash/13_4...trollers_Share_Blame_194287-1.html

Finaly, some inevitable acknowledgments of the root cause of this accident by Brazilian authorities. They still cling to partially/potential/unspecified fault by the legacy crew. However, as it has been known by anyone who has bothered to read the prelim accident reports plus reports on this crash, the primary cause was ATC clearing both airplanes on the same airway at FL370 in oposite direction and then failing multiple times for over 1 hour to take corrective actions as the planes converged.

Sad that it has taken so long. Sadder that misplaced Brazilian patriotism has tried to pin the blane on the Legacy crew. Saddest of all that 154 people are dead because of a basic and fundamental ATC error and string of missed opportunities to correct.

Lets hope the final report is professional and dispassionate in pointing the causes.
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Summa767
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Tue Jan 23, 2007 11:16 pm

What a misleading header! How biased can one be?

Thank you for providing this link, but anyone who follows it, will see that the investigators are not putting the blame on ATC as Baron95 has managed to spin it, but instead "a share of the blame".

And on the question of patriotism, it is best to look for specks's in one's eye before looking for it in others, one could well find a beam.

I have every confidence that the final report will be "professional and dispassionate in pointing the causes"

[Edited 2007-01-23 15:18:43]
 
katekebo
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Tue Jan 23, 2007 11:35 pm

I think Brazilian authorities are demonstrating their professionalism by setting false patriotism and politics aside, and making an objective assessment. If only America government had enough integrity to acknowledge it's mistakes and correct them in due time .....
 
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acontador
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 12:14 am

Interesting to hear the comments from our Brazilian A.netters...

But why scratch the surface when you can go deeper. The big question is really: Why did ATC clear both airplanes on the same airway at FL370 in opposite direction and then failing multiple times for over 1 hour to take corrective actions as the planes converged?

When you start looking at working conditions, local ATC setup, etc., you start to sea the underlying causes, which if not remedied will lead to another incident/accident sooner or later.
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FMAL
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 12:23 am

Very misleading title. Veja, the main Brazilian weekly magazine (our "Time") brings transcripts of the Legacy's black box this week, where the Legacy pilots realize, instants after the crash, that their TCAS/Transponder was off.

This is why they suddenly reappear with full info on the controller's radars moments after the crash. However, this does not excuse the apparent fault by ATC also.

What the reports will likely show is that mistakes by the Legacy pilots and by ATC cause the crash, and both will be blamed for their respective mistakes.
 
LVTMB
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 12:53 am

Well, it has been clear from day one that the obvious main cause of the accident was the fact that both airplanes were placed at the same FL in opposite directions. If you consider that, the obvious conclusion is that air traffic control (as a system) failed, since its main reason of existence is to ensure air traffic separation. Having said that, contributing factors seem to be the Legacy pilots failure to realize their transponder was off, as well as all of the ATC communications snafu.

I have a question for those familiar with the accident investigation: Have the CVR and FDR from the Gol 737 provided any indication of why the Gol crew failed to detect the oncoming Legacy? Was the 737's transponder working? Did TCAS detect the Legacy? By the way, not implying anything whatsoever, just curious.

MB
 
katekebo
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 12:59 am

Quoting LVTMB (Reply 5):
Was the 737's transponder working?

Apparently, yes (based on the available information)

Quoting LVTMB (Reply 5):
Did TCAS detect the Legacy?

No, because the Legacy transponder was off. The TCAS can detect traffic only if the transponders in BOTH aircrafts is on. With the transponder in the Legacy off, there is no way the TCAS in the Boeing could detect the approaching airplane.
 
LipeGIG
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 1:16 am

I will wait for the final report, but in a situation that a LOT of faults from ATC & Legacy Crew, i can only say something: the only one without folk was Gol Crew: without TCAS confirmation (impossible as it's clear Legacy transponder was off), lack of ATC communication, even with a top equipment they paid the higher price in this tragic accident, and despite any patriotism, 154 people died, mostly Brazilians.

Felipe
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FMAL
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 3:00 am

I think there's very little patriotism at hand here.

I'm sure that, as in most of the air disasters in the world, investigations will reveal that a series of oversights and faults, both by controllers and by the Legacy crew, will be the cause of the accident.
 
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 4:00 am

That wasn't the most descriptive of articles, but it mentions that the controllers who are part of the military could spend 12 years in jail for their actions. It seems like a mistake like that which was not intentional doesn't deserve 12 years in jail. That sounds more like a sentence of revenge. Are there precedents on penalties on controllers in other parts of the world that are responsible for incidents?
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tommytoyz
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 4:17 am

ATC has the responsibility to separate traffic, that's why they're there and clear aircraft in a manner they do and aircraft follow their clearances.

Even if the Legacy crew had forgot to switch on their transponder or switched it off somewhere in flight, ATC should have noticed it and asked the crew to ident.

The fact that one plane does not return a transponder signal or ident does not excuse clearing the planes onto conflicting courses and keeping them on conflicting sources for 1 hour or more without correcting the clearances.

After all, the pilots were flying their clearances correctly. If ATC needed more information from the Legacy, they should have said something about it.

If ATC were unable to communicate with the Legacy or of it's exact location, and had wanted to solve the conflict in the previous clearances, they should have told the GOL flight to change course/altitude.

The fact is, ATC lost track of the conflict and never resolved it.

This has nothing to do with transponders being off. ATC should be able to notice if an aircraft has it's transponder off or not right away.

It's also en error to say that if the transponder had been on, that the clearance error would not have happened or would have been resolved before the crash - nobody knows that. All we know is ATC failed in their basic job and they just as well could have let the conflict stand - transponder signal or no transponder signal. ATC already had enough information to know there was a conflict even without a transponder signal and they failed to act on it.

ATC should not become so lazy as to say to themselves that should they make an error that TACAS will bail them out, especially if they have on their screens an aircraft without a transponder signal.

The lack of a transponder signal from the Legacy should have been a red flag to ATC to be even more proactive, as that's not a regular thing.

Yes, TACAS would have warned the pilots that ATC put them on a collision course, but then ATC also knew TACAS wouldn't work in this case with a missing transponder signal.
 
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acontador
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 5:24 am

And still nobody has even started to answer the big question:

Quoting Acontador (Reply 3):
Why did ATC clear both airplanes on the same airway at FL370 in opposite direction and then failing multiple times for over 1 hour to take corrective actions as the planes converged?

If we have a Brazilian ATC on board, maybe he could tell you a little about their working conditions...
Do not forget that this is not the US, and in particular in Brazil ATC is a huge problem.
It is a military organization, the guys working on the screens are NCOs under a strict chain of command, way understaffed and underpaid, there is no radar coverage around the collision area (no money for new radars), etc...are you getting my point?
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philb
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 9:01 am

Tommytoyz, your post is unbalanced.

Sure ATC has responsibilities and must take a percentage of the blame but an aircraft commander is 100% responsible for the safe conduct of his flight and should have been aware that his transponder was not active.

Come down off your patriotic high horse and show some balance.
 
andessmf
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 9:49 am

All accidents have a sequence of events that occur prior to the incident. If any of those events had not occurred, neither would the accident.

ATC may have made a mistake, but:

Quoting Philb (Reply 12):
an aircraft commander is 100% responsible for the safe conduct of his flight and should have been aware that his transponder was not active.
 
ULMFlyer
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 9:52 am

Quoting FMAL (Reply 4):
Veja, the main Brazilian weekly magazine (our "Time") brings transcripts of the Legacy's black box this week, where the Legacy pilots realize, instants after the crash, that their TCAS/Transponder was off.

Although Veja has done a very good job covering the accident, I thought this particular article was very confusing and refrained from posting here its content.

First of all, Veja only provided a translation of some CVR content, not the English transcripts, so it was very hard to judge how accurate it is. In the translation, the pilots note that the TCAS was off. Then Veja goes on to say that the TCAS is bundled with the transponder, so that they're either both on or off. Is this really the case? Baron95? Obviously, if the transponder is off, so is the TCAS, but I'm not sure the converse is true. Nevertheless, it seems both were off, as the B738 TCAS would be able to provide a RA if only the Legacy's transponder were on.

However, if the article is accurate, it provides evidence that the Legacy crew did not intentionally turn either equipment off. Not only there's no mention of this in the CVR (if there were, you bet people would be all over them), but also they seem surprised by the fact. But Veja then states that after they land, one of the pilots apologizes to the other, and then the magazine speculates whether this apology was for having turned the transponder/TCAS off (a cheap shot IMHO, but they at least unsuccessfully tried to contact the pilots for an explanation and let their Brazilian lawyer state that isolated quotes could be misinterpreted out of context).

I thought they should have released the original transcripts by now. Maybe we'll have to wait until the final report is released, as LipeGIG suggests. As of yet, I agree with Baron95 that the main cause rests with ATC, with an equipment malfunction contributing. Unless the crew blatantly failed to notice some PFD/MFD/panel indication that the transponder was off, I can't see how they'd be at fault.
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redflyer
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 10:22 am

Quoting Tommytoyz (Reply 10):
The fact is, ATC lost track of the conflict and never resolved it.

This has nothing to do with transponders being off. ATC should be able to notice if an aircraft has it's transponder off or not right away.

Early last year, I had ATC ask me to ident when the transponder on the old 172 I was flying was malfunctioning. Not sure why when a jet such as the Legacy is flying at altitude in the equivalent of class A airspace in Brazil, which should always be under the control of ATC, that ATC would not notice this problem. In the U.S. -- and under ICAO rules -- any aircraft flying in the equivalent of Class A airspace must be under the control of ATC and is considered to be flying via IFR.

Quoting Philb (Reply 12):
an aircraft commander is 100% responsible for the safe conduct of his flight and should have been aware that his transponder was not active.

What if his transponder was malfunctioning?

Yes, an aircraft commander is 100% responsible for the safe conduct of his flight, but that doesn't mean he can predict what other flights around him are doing. That is why at jet-cruise altitudes aircraft are under the watchful eye of ATC.
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ULMFlyer
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 10:44 am

Quoting RedFlyer (Reply 15):
Not sure why when a jet such as the Legacy is flying at altitude in the equivalent of class A airspace in Brazil, which should always be under the control of ATC, that ATC would not notice this problem.

Because they screwed up. It was clear on their scopes that they were not receiving the transponder signal from the Legacy. Yet, because of a shift change, they went for 24 mins without trying to contact the Legacy. When they finally did, she was in an area of poor radio coverage and couldn't be raised.
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tommytoyz
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RE: ATC At Fault In Gol 737-Legacy Collision In Br

Wed Jan 24, 2007 11:34 am

Quoting Philb (Reply 12):
Come down off your patriotic high horse and show some balance.

What does patriotism have to do with my post? Sorry, that's not called for.

Quoting Philb (Reply 12):
Sure ATC has responsibilities

Absolutely, ATC has responsibilities according to established international aeronautical rules and cross border agreements and I'm sure even domestic Brazilian laws and rules.

All I'm trying to say is that according to these rules and laws, ATC has the entire burden here. In any other situation, ATC would ask the non emitting jet to ident. That is to press the ident button on their transponder so that the controller can see their transponder signal. If this fails, or if the jet does not respond, then other traffic must be vectored to avoid the non responsive jet.

It's pretty standard procedure.

The basic fact here is that ATC was asleep at the wheel, got sloppy, was distracted, had internal miscommunication - whatever you want to call it. It's ATC that put them on the collision course. Both pilots were merely correctly flying their clearances unaware of the conflicting clearance of the other had, as they were both in different ATC sectors when they were given their clearances that put them on a collision course.

They were left on the collision course for so long that there is no excuse. This has nothing to do with a transponder being off. There was a conflict created by ATC and they did not try to correct it in time to avoid disaster. I also never heard them trying to contact the GOL flight to vector them.

TACAS probably would have averted the collision, but it being inop due to the transponder being off did not cause the collision nor put them on a collision course. ATC did that.

The fact that it took ATC so long for them to notice the conflicting clearances makes it clear as day to me they were not paying attention when they should have, not to mention the fact that the clearances should never have conflicted in the first place. The Legacy should not have been cleared to that altitude on that heading. Ditto for the fact that ATC also never noticed that the transponder was as off.

When there is an area that is known for poor radio coverage, it makes it even more important for ATC to be vigilant about a/c clearances going into those areas and sector handoffs, not less - because corrections may be impossible - as seen here.

Basically, ATC caused this. Shame on them for trying to push off the blame. End of story for me.
 
art
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 11:47 am

Quoting LVTMB (Reply 5):
Well, it has been clear from day one that the obvious main cause of the accident was the fact that both airplanes were placed at the same FL in opposite directions.



Quoting Tommytoyz (Reply 10):
ATC has the responsibility to separate traffic, that's why they're there and clear aircraft in a manner they do and aircraft follow their clearances.

It appears that ATC made a basic mistake and put 2 aircraft on a potential collision course. To me that is the essence of the matter. Any failure by the pilots concerned to become aware of the ATC error is not of the same order to me.

The gravity of the ATC's "crime of commission" dwarfs any "crimes of ommision" by the pilots, in my opinion.
 
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 12:37 pm

Quoting Acontador (Reply 11):
And still nobody has even started to answer the big question:

Quoting Acontador (Reply 3):
Why did ATC clear both airplanes on the same airway at FL370 in opposite direction and then failing multiple times for over 1 hour to take corrective actions as the planes converged?

If you go back to old threads you will see many points cited that may have contributed to that.

Renato Sayao iirc is the Federal Police Investigator. That investigation as far as I am concerned is bogus until we hear from the technical investigation (the duly proper investigation) being carried out by the airforce's Accident Investigation and Prevention Team (or some similar title).
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baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 4:24 pm

Quoting ULMFlyer (Reply 14):
Then Veja goes on to say that the TCAS is bundled with the transponder, so that they're either both on or off. Is this really the case? Baron95?

I am certainly not type rated on the Legacy/ERJs nor do I have accss to a flight manual. However, for the planes that I know, transponder and TCAS can be turned on/off independently.

If the Legacy transponder was on but TCAS was off, the GOL/737 TCAS would have interrogated the Legacy transponder and gotten a repply, issued an RA/warning to the Gol crew. The Legacy, on the other hand would have gotten no RA/warning as their TCAS was off (either not interrogating, or not allerting).

On the other hand, if the Legacy transponder was off, but their TCAS was on, their TCAS would still have interrogated the GOL transponder and issue an RA. The GOL/737 would not get an RA as their TCAS would not get a transponder reuturn from their interrogation.

I should note, that this is the mode in planes where TCAS was added as a requirment after main avionics were certified. It is possible that in the Legacy, there is some coupling of transponder and TCAS, but I doubt it. It is certainly possible to turn off TCAS RA alerts with transponder on.

I hope this help, but unfortunately in this case I do not have definitive information. Any ERJ drivers from American Eagle or such out there that can clear up?

Maybe I'll cross post it on tech/ops and see if I get lucky.
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baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 5:10 pm

Quoting Acontador (Reply 3):
The big question is really: Why did ATC clear both airplanes on the same airway at FL370 in opposite direction and then failing multiple times for over 1 hour to take corrective actions as the planes converged?

When you start looking at working conditions, local ATC setup, etc., you start to sea the underlying causes, which if not remedied will lead to another incident/accident sooner or later

There have been too many detailed discussions here as to the causes of this accident - and you are right, the primary objective should be to learn what went wrong so it can be fixed and not happen again. The tone was set wrong by the minister of defense of Brazil (all ATC report to him and all accident investigators report to him) stating early on that ATC was not at fault and that the Legacy crew caused the accident.

To recap the facts that are not in (serious) dispute:
1 - Controllers at the departure airport cleared the Legacy all the way to the destination at FL370, which of course takes precedence over the flight plan filed altitudes (however, it took the Brazilian Minister of Defense and the Brazilian press a few months to stop talking about the Legacy violating the flight plan altitudes).
2 - Brazilian ATC software, has a "feature" (which I call a fatal flaw), where it will automatically update the cleared altitude of plane to the flight plan altitudes EVEN IF A CONTROLLER NEVER CLEARS A FLIGHT TO THAT ALTITUDE. Therefore, as the Legacy passed over Brasilia VOR, the data block of the Legacy was changed to indicate FL360 as the cleared altitude.
3 - Brazilian ATC sector controllers hand-off the Legacy flight to other sectors saying that they were at FL 360. A shift change occurs and again the departing controller briefs his replacement as the Legacy being at FL360. While all that is going on there is a total of only 3 (THREE) targets on that sector.
4 - For 12-24 minutes (I forgot which) after Brasilia the Legacy has a datablock listing that it is at FL370 while being cleared to FL360. Controllers still do nothing, make no calls.
5 - After that, first transponder returns, then communications become intermittent. Only primary radar returns (which have altitude readouts of +- 1,500 feet are available till the collision. We are still 30 minutes away from the collision, still ATC does nothing to clear the airspace. Note that primary radar was still showing the Legacy around FL370+- 1,500 feet.
6 - Now, minutes before the collision, both ATC and the Legacy are trying desperately to reach each other - multiple calls from all sides, only one partially copied by the Legacy. ATC makes no attempt at relaying communications via other aircraft in the area (I'm not sure if that would help, but after the collision the Legacy did get relay comms to ATC via a cargo flight). Is it possible that the Legacy crew is now fidgeting with Radios and transponders to be seen and heard? Yes. Is it likely that they turned off transponder? No. Is it possible that TCAS was off? Yes. Likely that they turned if off? No.
7 - Brasilia sector hands-off the Legacy flight to Manaus, briefing the flight at FL360. No mention that they had no secondary radar (precise altitude). No mention that they have not been cleared to FL360 or 380 as per flight plan. No mention of any concern by Brasilia controllers.
8 - ATC does nothing to move the Gol/737 out of the way.
9 - ATC does nothing to tell "GOL 1907 traffic, 12-oçlock opposite direction 5 miles, FL360", which you would normally get in a RSVM 1,000 ft vertical separation situation.
10 - No call from ATC to the GOL saying traffic 12 o-clock, altitude unknown as is customary when secondary radar (transponder mode C) is not being received.
11 - ATC does nothing to climb, descend or vector the GOL around the possible conflict, EVEN THOUGH THERE WERE NO OTHER PLANES ABOVE, BELOW, OR TO EITHER SIDE.
12 - If you want to be a stickler, BOTH CREWS failed in their see-and-avoide responsibilities since the flights were in clear air with excellent visibility.
13 - The saddest of all things happened - an accident, with a monumental ATC failure as the root cause and several missed opportunities to recover from the root cause. 154 people died. God bless them and their families. PLEASE NOTE THAT THE ATC SYSTEM IS SUPPOSED TO WORK WHEN TRANSPONDERS FAIL, WHEN RADAR FAILS, WHEN COMMS FAIL. It is truly a system where you assume that any link can fail at any time and IFR flights are still properly separated.
14 - Minister of Defense claims that Legacy crew is at fault and ATC did nothing wrong.
15 - Legacy crew has their passports sequestered and can't leave the county for weeks with no charge or process as a critical witness.
16 - ATC workers in CIMDACTA 1 (Brasilia), KNOW THEY WERE AT FAULT, and immediately start a white strike, handling all flights by the book with standard separation. This throws the entire Brazilian aviation system into chaos, with hundreds of cancelled and delayed flights.
17 - When subpoened to give a deposition by the federal police investigators, ALL, Brasilia ATC shift workers obtain a fraudulent doctor's certificate that they are sick and unable to attend a deposition. ALL OF THEM did that. And it stood like that for weeks.
18 - Eventually, due to the weight of the evidence, Brazilian Airforce (in charge of the investigation) officials and the press, start to hint that "ATC may have failed, but primary cause of the accident, rests with the Legacy crew".
19 - Now, they are "co-culprits, both equally responsible", because ATC was supposed to have implemented procedures when the Legacy crew turned off the transponder. NOTE: STILL NO TALK OF ATC BEING THE ROOT CAUSE FOR CLEARING BOTH FLIGHTS TO FL370.
20 - Eventually it may change to ATC being at fault with the Legacy crew contributing due to transponder issue, but it will be a long time till we get there. If ever.
21 - When the final report comes out, there is little reason to expect that it will zero in on the root causes. It will be a defensive (of ATC) report, simply because the organization in charge of the report is the same organization in charge of ATC and their boss already said that ATC did no wrong.

I hope this helps and that I didn't come across as too biased. I do believe that someone must provide a counter to the snow job of the Brazilian Minister of Defense, the Brazilian Airforce investigators and the Brazilian patriotic press.

Cheers.

[Edited 2007-01-24 09:14:33]
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speedbird128
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 6:55 pm

Quoting Tommytoyz (Reply 10):
ATC should not become so lazy as to say to themselves that should they make an error that TACAS will bail them out

THat's out of line Mr TommyToyz. Don't throw your toys about on a subject you apparently know nothing about.

And it is TCAS. Not TACAS.

One day once you've been an ATC and you can understand the responsibility and the number of lives you have to deal with every day - you can comment on how lazy we should not be.
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zeke
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 7:14 pm

Quoting Baron95 (Reply 20):

I hope this help, but unfortunately in this case I do not have definitive information.

Also would be interested to know what warning one gets in the legacy in this situation of a TCAS or transponder being off in flight, in the Airbus we get messages if TCAS is not selected on in flight, or in TA mode only.
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tommytoyz
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Wed Jan 24, 2007 7:48 pm

Quoting Speedbird128 (Reply 22):
One day once you've been an ATC and you can understand the responsibility and the number of lives you have to deal with every day - you can comment on how lazy we should not be.

Speedbird,
I'm referring to the way the government officials were trying shift the blame onto the pilots......by that logic, ATC should be able to rely on pilots avoiding collisions by themselves since they have due to TCAS. I said it badly but meant to point out the logic in the official's argument.
 
baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Thu Jan 25, 2007 1:28 pm

Quoting Zeke (Reply 23):
Also would be interested to know what warning one gets in the legacy in this situation of a TCAS or transponder being off in flight, in the Airbus we get messages if TCAS is not selected on in flight, or in TA mode only.

I checked around, found no ERJ drivers or people with access to the flight manual to confirm this. However I have confirmed that the transponder and TCAS can be turnned on/off independently in every aircraft known to these pilots. A warning message (as you describe Zeke) seems to also be standard if transponder is on and TCAS is off or vice-versa.
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baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Thu Jan 25, 2007 1:33 pm

Quoting Speedbird128 (Reply 22):
One day once you've been an ATC and you can understand the responsibility and the number of lives you have to deal with every day - you can comment on how lazy we should not be.

I don't think anyone in this thread has minimized the importance of ATC and how critical their role is to flight safety. I have dealt with abnoxious controllers (I fly mostly in the DC-New York-Boston area so no surprise there), but I have yet to encounter an incompetent approach/departure/center controller. Some green local/tower controllers, yes. TRACON/Center controllers no.

Which makes it a global emabrassment that professional controllers, when asked to give a statement about an incident on where 154 people died in a head-on, straight and level collision with both planes under positive radar control, call their doctors and produce a phony "I am sick" medical certificate.

These people are an embarrassment to the ATC procession and NO ATC professional anywhere in the world can condone this.
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ULMFlyer
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Thu Jan 25, 2007 2:05 pm

Quoting Baron95 (Reply 26):
Which makes it a global emabrassment that professional controllers

I wouldn't go that far. The true embarrassment is the legislation that allows the criminalization of air accidents, which is not the case is the US. I'm sure the controllers are being instructed by their lawyers and I can't really blame them for exercising their right to remain in silence.

I suppose not many people in this world would be forthcoming with information that would land them in jail for involuntary manslaughter. I apologize if I misunderstood your post.
Let's go Pens!
 
aa87
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Thu Jan 25, 2007 2:07 pm

Question to our airline pilots: putting aside whether, why, how, if the Legacy's TCAS was on or off or not working ..... isn't it plain common sense to visually check it every few minutes ? I can understand not noticing the transponder is off or not working, but the visual display is a basic feature of the TCAS system.

For the record, I have utmost admiration for prof. pilots, especially because I wanted to be one but am a mere mortal, inactive, low hour Cessna pilot. And I generally agree it sounds like ATC is 90%+ to blame. That said, I've been up front dozens of times (pre-9/11 days) and I have noticed that, regardless of phase of flight, the crews generally don't seem to pay much attention to TCAS. Flame me if you want, but is it possible the Legacy crew didn't notice it was off because they were accustomed to ignoring it ? does anyone think its possible crews have been desensitized by TCAS so that they don't scan it unless they hear an aural warning ?
 
baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Thu Jan 25, 2007 3:40 pm

Well, level at FL370, in clear air, under positive radar/ATC control, over the Amazon forest with only 3 other planes reported on the same sector, I'm not sure many pilots would be activelly scanning a blank TCAS screen. There simply wouldn't be any targets on it.

I, for one, still find really hard to believe that the transponder was actually OFF or in the STANDBY position on the Legacy. There would be no reason, logic, to it, unless they were trying to reset it, after not seeing a blinking interrogatin/response light from ATC for some time. Still not likely that it was off. Not impossible, just not very plausible. Pilots typically don't touch the transponder after take-off unless instructed by ATC to reset, change code, ident, etc. It is just not something you do.
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speedbird128
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Thu Jan 25, 2007 9:01 pm

Quoting Tommytoyz (Reply 24):
I'm referring to the way the government officials were trying shift the blame onto the pilots......by that logic, ATC should be able to rely on pilots avoiding collisions by themselves since they have due to TCAS. I said it badly but meant to point out the logic in the official's argument.

 Smile

Perhaps the official (and that term 'official' used loosely) should close his mouth a little. It seems there are very few actual hard facts out there - and much of this whole thing is speculation.

I hope they find all the causes of this accident, and publish it *accurately* so others can learn from the mistakes made. Covering up is not going to get anybody anywhere...
A306, A313, A319, A320, A321, A332, A343, A345, A346 A388, AC90, B06, B722, B732, B733, B735, B738, B744, B762, B772, B7
 
ltbewr
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Thu Jan 25, 2007 9:37 pm

In this case, the Brazilian investigative authorities, the courts and prosecutors should grant immunity to the ATC personal to be able to get their cooperation and testimony. When one figures they will go to jail for making a mistake, they will not cooperate and of course their lawyers and unions will advise their members/employees not incriminate themselves. Of course, key ATC personal should be fired and face non-jail penalties for allowing this to happen. Brazil should change it's laws to international standards like that of the USA, EC, to make immunity the policy, not jail, so the truth can come out in timely fashion. There should also be better laws to limit the statements of the investigative, military and police authorities when an investigation is in process to make sure it is being properly done.
Let's hope it isn't too late to grant this immunity and the truth can come out as to all parties parts in this tragedy.
 
aa87
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Fri Jan 26, 2007 2:06 am

Quoting Baron95 (Reply 29):
Well, level at FL370, in clear air, under positive radar/ATC control, over the Amazon forest with only 3 other planes reported on the same sector, I'm not sure many pilots would be activelly scanning a blank TCAS screen. There simply wouldn't be any targets on it.

That's exactly my point. We now have 2 tragic cases (other being the Swiss midair a few years ago) proving that TCAS, even when functioning, is not a substitute for air crew vigilance. If the Legacy's TCAS was in fact operating at all, that still did not result in a timely warning to either crew. As a backseater I've taken great comfort in TCAS, but less so now. I think scanning TCAS every few minutes -- which takes about 7 seconds -- in all phases of flight should be taught. Out over the Atlantic, with hours of nothing to do but sequenced position reports, crews still scan their instruments, right ? fuel, HSI etc.

Just shows again the human element always was and always will be THE weak link
 
WSOY
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Fri Jan 26, 2007 6:58 am

A summary of the accident here, and more, of the recent cases.
http://www.airaccidentdigest.com/123106.html
"Nukkuessa tulee nälkä" (Nipsu)
 
baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Fri Jan 26, 2007 12:47 pm

Quoting ULMFlyer (Reply 27):
The true embarrassment is the legislation that allows the criminalization of air accidents

Agreed.

Quoting ULMFlyer (Reply 27):
I'm sure the controllers are being instructed by their lawyers and I can't really blame them for exercising their right to remain in silence.

That is not what they did though. They got blatantly fraudulend doctor notes - like school children do in the US.

They should behaved professionally, attend the deposition, and if they believed they could incriminate themselves they could refuse to answer certain questions as is their right. There is an honorable way to exercise your rights, and there is the embarrassing way. They chose the latter.
Killer Fleet: E190, 737-900ER, 777-300ER
 
baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Fri Jan 26, 2007 1:27 pm

Quoting AA87 (Reply 32):
I think scanning TCAS every few minutes -- which takes about 7 seconds -- in all phases of flight should be taught.

OK - I can go along with that, HOWEVER, you have to realize that scanning TCAS every few minutes would not have helped in this case, right?

Lets do some math: The planes were converging head on at a clsure rate of about Mach 1.6 -about 900 knots. Most TCAS setups would not show/highlight/alert anything outside 10nm. The distance between these two planes would go from 10nm to zero in 40 seconds!!!!

In my mind, see-and-avoid, i.e. four pair of Mk II eyeballs looking outside the window scanning for traffic, had the best chance of avoiding this tragedy, once ATC put these two planes on a collision course. 99.9% of the time airliners are flying in the flight levels in cruise they are in visual conditions.

Quoting LipeGIG (Reply 7):
i can only say something: the only one without folk was Gol Crew:

I think he meant to write "fault" where it says "folk".

Technically, an NTSB style final repport is likely to list as contributing factors to the collision "The failure of both flight crews to see and avoid the other aircraft". It is standard in virtually all (if not all) mid-air collision in VMC.
Killer Fleet: E190, 737-900ER, 777-300ER
 
baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Fri Jan 26, 2007 1:49 pm

Quoting WSOY (Reply 33):
A summary of the accident here, and more, of the recent cases.
http://www.airaccidentdigest.com/123....html

Thank you for the link WSOY.

I'd like to point out that there are some innacuracies on the accident news letter (e.g. that it was the right wing/winglet of the Legacy that struck the 737s wing - it was in fact the left winglet - and saying that there were 155 on board the 737 - there were in fact 154).

Overall though it does a nice job of enumerating the two critical points that the final report must address: 1 - Why did ATC placed both planes on a collision course and didn't correct the problem before the collision and 2 - Why did TCAS failed to issue an RA that could have recovered from the ATC mistake. The answers to (1) will cause significant changes to the Brazilian ATC system. The answers to (2) may lead to changes to the TCASII Software.
Killer Fleet: E190, 737-900ER, 777-300ER
 
aa87
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Sun Jan 28, 2007 2:24 pm

Quoting Baron95 (Reply 36):
Why did TCAS failed to issue an RA that could have recovered from the ATC mistake

That's the key here. Of course there was a tragic ATC error, but TCAS was supposed to be the safeguard.

As to your response above -- and remember I have no experience with actually using TCAS -- my point is not that the Legacy crew could have noticed and reacted within 40 seconds (though why not ??). My point was that, if TCAS was not on or not performing normally, regular scans would have allowed the Legacy crew to notice that. And even if no warning is given outside 10NM, presumably regular scans would have allowed the crew to notice a target directly in their flight path, well before the "40 second warning". Do you disagree ? It simply seems to me that for many flight deck crews, TCAS seems to be considered a smoke alarm, not in-cockpit radar. A smoke alarm is silent for only 3 reasons: 1) there's no fire 2) it's off/no power or 3) its defective.

So as you say, the ultimate question is why TCAS didn't prevent this tragedy, even given the causal ATC errors.
 
baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Sun Jan 28, 2007 4:58 pm

Quoting AA87 (Reply 37):
So as you say, the ultimate question is why TCAS didn't prevent this tragedy, even given the causal ATC errors.

I understand and agree 100% with your point on the TCAS scan. On most planes TCAS OFF will show up on the PFD (Primary Flight Display) or ND (Nvigation Display), both of these (specially the PFD) are activelly scanned by the pilots. I believe (but I don't know) that I and most pilots would eventually notice the TCAS OFF flag in cruise flight, but I honestly do not know how long it would take to notice. After every checklist completion I tend to do a full pannel scan. In cruise, being paranoid, I also do regular full pannel scans looking for possible trouble or odd things - but I can't tell you how often I do that. I guess is that it varies between 5 min and 30 min on average.

As for a TCAS RA, most crews these days are trained in the SIM to act instinctively and FAST on an RA. I believe that current training is even too extreme. If you search this forum you'll see the thread on a BA flight departing MIA or ATL where several flight attendands were seriously injured because the crew acted very forcefully on a TCAS RA. I'd hate to see someone die aboard a plane because the crew put the plane on -1g because of a TCAS RA, when typically you have several seconds to act and manouver smoothly. But that is not how crews are being taught to react to TCAS. Crews are being taught to react to TCAS as if a collision is imminent and climb or descent near the edges of the flight envelope. That is not safe to unbuckled passengers.
Killer Fleet: E190, 737-900ER, 777-300ER
 
Electech6299
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Sun Jan 28, 2007 10:38 pm

Quoting Baron95 (Reply 38):
I'd hate to see someone die aboard a plane because the crew put the plane on -1g because of a TCAS RA, when typically you have several seconds to act and manouver smoothly. But that is not how crews are being taught to react to TCAS. Crews are being taught to react to TCAS as if a collision is imminent and climb or descent near the edges of the flight envelope. That is not safe to unbuckled passengers.

I'd hate to see several hundred people die due to a midair because the guidance is relaxed. There is no guarantee of "several seconds" of leeway- especially if the conflicting traffic is not equipped with TCAS and/or does not respond as directed by TCAS. Even so, unbuckled pax would be a secondary concern for me- the F/As would be significantly more likely to be injured in an abrupt maneuver, and they are required to perform their duties. Nobody else (OK, maybe the air marshall) is required to be on that flight, and the odds of some random pax being injured in an unlikely scenario are significantly lower than the odds of cabin crew being injured. (but maybe that's my bias as an occupational health specialist...)
Send not to know for whom the bell tolls...it tolls for thee
 
aa87
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Mon Jan 29, 2007 11:12 am

BTW, I know TCAS will not register a warning for non-TCAS equipped targets, but does such a target show on the TCAS display, like an unidentified target on ATC radar ? if yes, reinforces my point about need to visually scan TCAS regardless. And if not, all the more reason -- as I think you said Baron95 -- to do visual scan for see and avoid in all non-IMC situations.

Horrible crash, very very curious to hear what the technical conclusions are and if any significant disagreements from the various interested parties.
 
baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Mon Jan 29, 2007 2:11 pm

Quoting Electech6299 (Reply 39):
and the odds of some random pax being injured in an unlikely scenario are significantly lower than the odds of cabin crew being injured.

Agreed. Flight attendants in the galley handling hot foor with loose food carts all around them are at a siginificant risk of injury in CAT, TCAS RA Manouvers etc. I just don't think that the flight crew needs to be so "enthusiastic" in the coontrols when they get an RA.
Killer Fleet: E190, 737-900ER, 777-300ER
 
baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Mon Jan 29, 2007 2:32 pm

Quoting AA87 (Reply 40):
BTW, I know TCAS will not register a warning for non-TCAS equipped targets, but does such a target show on the TCAS display, like an unidentified target on ATC radar ?

AA87, I'm not sure how you got this idea that a non-TCAS target will not display. If it has an active transponder and is withing range it will display.

I guess I should take the time to attempt to explain TCAS.

TCAS sends out transponder interrogations just like an ATC Radar. Any transponder (Mode A [no altitude info], C, S) equipped airplane within range should respond to the TCAS interrogation, and if within the selected display range (normally 10 miles) it will be displayed. A traffic advisory will be issued for conflicting Mode C or S targets at the same altitude and mode A targets at any altitude.

If the aircraft is equipped with TCAS II (like the 737, Legacy and all large transport aircraft) and the target is equipped with Mode C or S (altitude repporting) the TCAS II will issue a climb or descend Resolution Advisory (RA).

If the target is also equipped with TCAS II the two TCAS will coordinate the RA - instruct one plane to climb and the other to descend.

TCAS IV, if it ever comes into being will issue RAs with horizontal commands as well (e.g. climbing left turn to one plane and descending right turn to the other).

I hope this clears it up.
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aa87
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Tue Jan 30, 2007 9:12 am

Thaks Baron, I meant issue an RA, not that it won't display non-TCAS targets. Anyway, in my mind your explanation of TCAS just reinforces my view it should be checked visually every minute or so. Non-transponder equipped planes shouldn't be in or even on the edge of controlled airspace, so unless its an errant crop duster or an F-117, chances are pretty high TCAS will at least visually show a potential threat.
 
baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Tue Jan 30, 2007 1:15 pm

Quoting AA87 (Reply 43):
Anyway, in my mind your explanation of TCAS just reinforces my view it should be checked visually every minute or so.

Agreed, so long as the scan is look out the window, look out the window, look at TCAS screen, look out the window, look out the window, look at TCAS screen  Smile

Quoting AA87 (Reply 43):
Non-transponder equipped planes shouldn't be in or even on the edge of controlled airspace, so unless its an errant crop duster or an F-117, chances are pretty high TCAS will at least visually show a potential threat.



It would be nice if it were so, but of course it is legal (in the US) to opperate non-transponder planes in most of controlled airpace (with the exception of class-A, Class B, Class C, etc). Even in class B, C it is possble to get special dispensation to opperate without transponder.

Bottom line, get those Mark II eyeballs pointed outside the cockpit unless in IMC.
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art
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Tue Jan 30, 2007 2:14 pm

Perhaps I'm being ignorant, but why can't there be an audible warning when a new return appears on the screen?
 
baron95
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RE: ATC At Fault In Gol 737-Legacy Collision In Brazil

Tue Jan 30, 2007 4:58 pm

Quoting Art (Reply 45):
Perhaps I'm being ignorant, but why can't there be an audible warning when a new return appears on the screen?

Any new return? That would be extremely distracting. On approach on a busy terminal area you are likely to have a few returns on the scope.

TA/RAs on the other hand have audible alerts - prior to that, traffic will change colors on the display as they start to become "interesting" meaning a potential conflict.

You need to be careful with too many alerts in the cockpit. If you get pilots conditioned that 99.9% of the alerts are irrelevant, they'll start ignoring all alerts and miss that 1 in 1,000 that is of consequence.

I think TCAS has a reasonoble balance. Perhaps the only change I'd like to see implemented is that if someone puts a transponder in stand-by/off or a TCAS in off position it reminds the pilot every 10 minutes audibly that it is off.

For example, you are getting too many alerts on TCAS because you are overflying an area with lots of mode C only traffic. Then you mute/turn it off and forget to turn it on. I'd like the system to allert me 10 minutes later of that fact.
Killer Fleet: E190, 737-900ER, 777-300ER