Mid-air collision over Brasil

[Richard_Brazil]

Poster George Rock in Brazilian Congressional News

From the official news agency of the Brazilian Chamber of Deputies, this evening. In paragraph four to end, the main focus is George Rock, a poster here. He seems to have successfully taken the fight from online to the real world.
-Richard

Consolidated - 28/05/2007 19:35

Internauts criticize thesis that transponder was turned off
Anna Izabel
[Photo, bearded Congressman in front of PC]

[Photo Caption:] Marco Maia: "Perhaps the American pilots could give us elements [showing] that the transponder was turned off involuntarily"



In a chat organized by Agência Câmara with the report referee of the Aviation Crisis CPI [Parliamentary Commission of Inquiry], congressman Marco Maia (PT-Rio Grande do Sul), air traffic controllers and aircraft pilots criticized the Federal Police investigations that point to the possibility that the Legacy jet's pilots had turned off the aircraft's transponder. The majority believe that for a pilot to intentionally turn off the equipment would be a suicidal act.

Internaut Márcio questioned why a pilot would turn off the transponder knowing that he would be risking his life. Marco Maia affirmed that he also did not understand the reason, but remembered that the investigation proved that the equipment was turned off. The Congressman explained that, on analyzing the data on the accident, he did not manage to identify how the transponder could have been turned off involuntarily. "That is why we are convoking the American pilots to testify to the CPI. Perhaps they can give us elements that permit us to believe is this affirmation that the transponder was turned off involuntarily."

The report referee explained that the CPI is analyzing all the information relative to the accident with the Gol plane. "Various factors contributed to the collision, since an accident like this does not occur only for one error, but rather because of a sequence of errors. In this sequence it is possible, yes, to identify responsibility by the American pilots."

Internaut George Rock asked the Congressman in which data he based his affirmation that the Legacy jet's transponder was turned off. Marco Maia affirmed that his declarations are based on the forensic examinations undertaken both by the companies and by the Federal Police. "The Legacy's transponder had no defect and, therefore, it was turned off."

Technical Problems
Georgerock remembered, during the chat, that the National Transportation Safety Board (NTSB) - an international entity in the area of flight security - emitted recommendations that there be a prominent warning in case of the transponder and TCAS being turned off. Marco Maia affirmed that the internaut's concern is pertinent, because, up to the present, the transponder does not have an alarm in case of failure or disconnection. "This is a recommendation that is being given, including to the manufacturers, for them to include an audio alarm system in new transponders for these cases".

The internaut pointed out other problems such as breakdowns in TCAS, transponders and radios, which have been happening since 2005, the use of non-electricity-conducting silicone in the transponder's connecting terminals, which may interfere with the equipment's functioning; and incorrect information on onboard computers. Marco Maia affirmed that these are new pieces of information, which will be analyzed technically. "What I can affirm to you is that the technical conditions, of the Federal Police as much as the Air Force, are adequate for the analysis of this information. Many of these analysis are being done or were performed in the United States or in Canada. However, you can be certain that we will have very precise information about the functioning of the equipment and the condition of both aircraft at the time of the accident."
Read More:
Controllers and pilots criticize Air Force and ask for greater participation in CPI

The Newsroom
Editing - Patricia Roedel

(Reproductino authorized as long as it contains the signature 'Agência Câmara')

Agência Câmara
Tel. [phone].1852
Fax. [phone]
E-mail:[email protected]

[Thylakoid]

Mr. Maia just stated that the causes were various and sequenced.
The xponder in question ... is the one that goes to standby mode after a few seconds, when a code is not set immediately? I've heard that from a pilot who flies an aircraft with one of those.

Obviously, the authorities have to find the people responsible for the accident, but the Federal Police or the Air Force are the least qualified, in my opinion, to make any findings in any air accident.
They need an independent entity, like the NTSB or the CTSB, composed of qualified accident investigators, to lead that type of analysis.

[alph2z]

Quoted from Richard_Brazil:
".....The internaut pointed out other problems such as breakdowns in TCAS, transponders and radios, which have been happening since 2005, the use of non-electricity-conducting silicone in the transponder's connecting terminals, which may interfere with the equipment's functioning; and incorrect information on onboard computers. Marco Maia affirmed that these are new pieces of information, which will be analyzed technically. "What I can affirm to you is that the technical conditions, of the Federal Police as much as the Air Force, are adequate for the analysis of this information. Many of these analysis are being done or were performed in the United States or in Canada....."

I have some experience with silicon (not) being used in circuits when I worked as an engineer at a major telecom company.

Because of serious problems with silicon very slowly migrating to contacts thus resulting in failures of mechanical contacts in switches and connectors due to detoriating contacts, we were forced in public telephone equipment to not used silicon based pastes.

It gave me major headaches then to find and confirm non-silicon replacements.

Major telephone companies had serious problems with silicon based products.
It is possible that the avionics industry has not caught-up to the telecom industry; or the newer designers have forgotten (or other) about the problems with silicon pastes.
.

[UNCTUOUS]

Tin Whiskers

The possibility also exists that the Legacy 600 transponder "failure into STBY mode" may be one of the early manifestations of the increased incidences (and consequences) of lead-free solder (imposed by the EU's RoHS Directive)
see link and
link
and link
.
Problems noted thus far are:
a. Tin whiskering (hair-like protuberances that grow over time from-lead-free solder that are capable of shorting out surface-mount components on circuit-boards or introducing intermittencies that can be frustratingly "once off" due to individual whiskers completing a circuit but then melting or recoiling under the current flow, or possibly as a result of the changed magnetic field). The requirement to be lead-free has caused the percentage of tin in some solders to exceed 60%.
.
b. Brittle fracture surfaces in lead-free solders causing intermittencies (a greater incidence with some of the new formulations of lead-free solder - of which there are about 700 variants).
.
If the two Legacy pilots want their "get out of jail free" cards stamped, they'd do well to acquire some expert testimony on the new failure modes in PFD's and other sensitive transponder type avionics that are slowly being introduced as the avionics industry compulsorily transitions across to lead-free solder - with its attendant new suite of intermittency problems.
.
When considering the performance variations between pb-rich and pb-free solder, think the difference between a glue that has had it's binding agent removed and replaced by greater amounts of gelatin. Alternatively think of what super-glue used to be like when it first came out and how uselessly ineffectual the modern denatured super-glue is nowadays (after the safety wowsers forced its manufacturers to make it less lethally effective).
.
You can read an extensive array of articles on "tin whiskers" and the problems it causes in modern electronics (since the introduction of lead-free solder) at this
link

[georgecrock]

Legacy Ground Speed as presented on Radar Data Tag on screen: 460 Knots

[broadreach]

Accident committee releases new info

From today’s Folha de São Paulo. I’ve just translated the essence of the article; please forgive any technical inaccuracies on my part.

The airforce’s accident investigation committee concluded that the Legacy pilots mistakenly switched off the aircraft’s transponder when they mistook it for the radio. Both are located in the same box on the control panel.

Folha were informed that the pilots made two attempts to enter radio frequencies. The transponder did not recognize these and switched off. At that point the message “TCAS Off” immediately appeared on the FO’s panel but went unnoticed.

After the collision the pilot asked “hey have you got the TCAS switched off?” to which the FO replied “Yes, the TCAS is off”. Two minutes later it appears to have been reset as the aircraft reappeared on ATC screens.

The accident committee expect to bring forward their report in August or September.

A possible reason for releasing the above, and which the article itself alludes to, is that it may help to clarify one of the issues in the post-crash dispute between controllers and the airforce, namely the existence of a communications “black hole” in Amazon coverage.

Full text in Portuguese:

Folha de São Paulo
Pilotos desligaram transponder, diz FAB
Comissão de inquérito da Aeronáutica concluiu que americanos confundiram o aparelho anticolisão e o rádio do Legacy
Joe Lepore e Jan Paladino teriam digitado os códigos de freqüência do rádio no transponder, prejudicando o funcionamento de ambos
ELIANE CANTANHÊDE
COLUNISTA DA FOLHA
A comissão de inquérito da Aeronáutica que investiga as causas da queda do Boeing da Gol em 29 de setembro do ano passado concluiu que os pilotos americanos Joe Lepore e Jan Paladino desligaram involuntariamente o transponder do jato Legacy que se chocou com o avião, confundindo esse aparelho e o rádio. Os dois ficam dentro da mesma "caixa" do painel de controle.
Conforme a Folha apurou, os pilotos teriam digitado os códigos de freqüência do rádio no transponder e, assim, prejudicado o funcionamento de ambos. O erro apontado pode explicar por que tanto o transponder estava inoperante quanto o rádio não funcionava adequadamente quando ocorreu o choque entre os dois aviões, em pleno ar, resultando na morte de 154 pessoas.
Mais de 20 tentativas de comunicação com o controle em terra foram em vão, porque, segundo as investigações, a freqüência de rádio estava errada e o transponder desligou depois de duas tentativas de inserção de códigos não reconhecidos pelo aparelho.
A digitação equivocada pode ter sido possível porque os pilotos não estavam devidamente preparados para pilotar o Legacy em sua primeira viagem ao sair da fábrica da Embraer em São José dos Campos (SP). Além disso, o rádio e o transponder ficam na mesma "caixa" do painel, entre o piloto e o co-piloto, e são parecidos.
Com o erro, o transponder ficou inoperante e imediatamente apareceu ao lado direito, em frente à poltrona do co-piloto Paladino, sem que ele se desse conta, a mensagem "TCAS off", informando que o TCAS (Traffic Allert and Collision Avoidance System, ou sistema anticolisão) se encontrava desligado.
Acionado pelo transponder, o TCAS evita acidentes com alertas visuais e sonoros aos pilotos, acompanhados da indicação de como eles devem agir, desviando o avião na horizontal e na vertical.
Conforme a gravação das conversas entre Lepore e Paladino, na caixa-preta do Legacy, um deles reagiu com surpresa ao perceber, depois do choque com o Boeing, que o sistema anticolisão estava desligado.
"Cara, você está com o TCAS ligado?", pergunta. O outro admite: "É. O TCAS está desligado". Cerca de dois minutos depois, o aparelho voltou a funcionar, com o transponder enviando sinais normalmente para os centros de controle de tráfego aéreo em terra. Isso indica que foi religado.
Resolvido o último grande mistério do acidente, a comissão poderá antecipar de setembro para agosto o anúncio oficial do resultado das causas do choque, confirmando as informações sobre a seqüência de falhas humanas, tanto dos pilotos quanto dos controladores de vôo, especialmente do Cindacta-1, de Brasília, que resultaram no maior acidente da história da aviação comercial brasileira.
O Comando da Aeronáutica afirma que não influencia conclusões nem prazos para a finalização do inquérito, mas a Folha apurou que vê com bom grado a antecipação do anúncio. Acha que isso poderá tirar um dos focos de tensão dos controladores de vôo, que desde o acidente têm se rebelado contra o Comando e promovido uma série de operações-padrão e greves, na tentativa de denunciar falhas do sistema de controle aéreo.
Caso seja confirmada a apuração de que os pilotos digitaram erroneamente os códigos do rádio e do transponder, isso aliviará, por exemplo, a importância no acidente da existência apontada por controladores de vôo de um "buraco negro" na região onde ocorreu o choque, em Mato Grosso, na altura da serra do Cachimbo.
O relatório deverá mostrar que, apesar de não conseguir contato com o Legacy, os Cindactas tanto de Brasília quanto de Manaus tinham comunicação normal com outras aeronaves na mesma hora e no mesmo espaço, que é sujeito a interferências magnéticas.

[Olindaguy]

Remarks to the comments of Broadreach

Comments to the posts of Broadreach:
You say "The airforce’s accident investigation committee concluded that the Legacy pilots mistakenly switched off the aircraft’s transponder when they mistook it for the radio. Both are located in the same box on the control panel."

I know that this is written in the article of Folha de São Paulo that you quote.
But I have strong doubts that this is the correct version, as the CVR of the Legacy doesn't even have a shadow of such a manipulation in the timeframe minus 5 and plus 5 minutes before/after the transponder went on stand-by at 19.02 UTC, about 30 miles North of BRS.

No remarks about radio manipulations (either Set 1 or Set 2) are present on the CVR. In fact the pilots talk continously about the landing in Manaus and the weather and the runway conditions up there at Eduardo Gomes.
I have strong doubts that this is the correct explanation.

You say further on: "A possible reason for releasing the above, and which the article itself alludes to, is that it may help to clarify one of the issues in the post-crash dispute between controllers and the airforce, namely the existence of a communications “black hole” in Amazon coverage".

You are correct to point this out as the current chief of ACC Brasilia, Commander Raulino, has now officially confirmed that there were black radar holes and blind spots at ACC Brasilia in September 2006, when the crash occured.

In the mean time these holes are "fixed" as a radar source from Manaus was brought in and is now fully available.

Once again it had to occur an accident before well identified safety issues got finally fixed.

All the best
Chris

[Brian Abraham]

Don't know what commonality there may be between the Legacy and ERJ 135 but this bit from post #63 at http://www.pprune.org/forums/showthr...=281098&page=4 perhaps raises some interesting questions.

I can remember some small glitches that popped up when the airplane was initially introduced in the U.S. but nothing big....well sort of. I can still remember being cautioned about the problem with the transponder, how if you start to change the code and then don't touch the knob for more than so many seconds the transponder would switch off. That's right, no warning or a default to the last code inputted, it would just switch off. Remember the crash in Brazil of the 737 after colliding with a Legacy?

[broadreach]

Olindaguy, thanks for the comments. The investigation committee must be under a tremendous amount of pressure from many sides and the interpretation of anything that comes out can be expected to have some bias.

For what it's worth, and I would guess it's about zero, the congressional investigation committee have said they've seen enough evidence to lay blame for the collision on the Legacy pilots. One might suspect that other scandals and other congressional investigation committees are getting more of the limelight these days, so that was the easiest way out. At least that's one distraction out of the way, and the Federal Police investigation also seems to have come to an end as it didn't include cross-examination of the airforce controllers.

The entire issue of civil vs military control now having been thrown back to the airforce, and with a handful of the military ATC people suspended and facing courts-martial/jail, the ATC front has gone very quiet.

[Brian Abraham]

From http://www.faa.gov/other_visit/aviat.../SAFO07005.pdf

Subject: Embraer Legacy/EMB-135, -140, -145 — Be Careful Where You Put Your Foot

Purpose: This SAFO calls attention to the possibility that a pilot of an Embraer Legacy, EMB-135 or -145 (sometimes called EMB-140 in marketing literature) might inadvertently change VHF radio frequencies or place the ATC transponder into standby mode during flight.

Background: During an investigation the FAA discovered that crewmembers who had the simple habit of placing their shoe on the footrest just below the instrument panel could inadvertently put the ATC transponder into standby mode, or change radio frequencies without the crew's awareness. Further, they found that pilots might not notice the corresponding indication on the Pilot Flight Display due to the white colored letters, which are not as noticeable as differently colored caution or warning indications.

Switching a transponder with a functioning traffic alert and collision avoidance system (TCAS) to standby mode renders the TCAS ineffective, and is therefore one of the most serious consequences of a pilot’s foot inadvertently contacting the radio management unit. Two airplanes equipped with TCAS would fail to see each other if they were on a collision course. Pilots could presume TCAS was operating normally if they failed to notice the subtle TCAS OFF indication on the Pilot Flight Display.

Recommended Action: Managers of part 142 training centers where pilot training on the Embraer Legacy, EMB-135, and EMB-145 is conducted should ensure that their trainers caution pilots of this latent hazard and emphasize the importance of being careful when using the footrests provided. Similarly, directors of safety, directors of operations, trainers, and check airmen for operators flying any of these Embraer models should immediately make this hazard known to their pilots and should make sure that it is addressed in their training programs, especially during flight training, supervised operating experience, and line checks.

Any questions regarding the content of this SAFO should be directed to the Air Transportation Division, AFS-200, at [phone].

Slice of Swiss Cheese anyone?

[arcniz]

Background: During an investigation the FAA discovered that crewmembers who had the simple habit of placing their shoe on the footrest just below the instrument panel could inadvertently put the ATC transponder into standby mode, or change radio frequencies without the crew's awareness. Further, they found that pilots might not notice the corresponding indication on the Pilot Flight Display due to the white colored letters, which are not as noticeable as differently colored caution or warning indications.

One of the sub-plots in the drama ensuing from the Gol-Embraer collision is the possibility of direct criminal charges against the Embraer crew and the ensuing arguments about whether or not the pilots should return to Brazilian jurisdiction to provide further testimony, or to submit to trial as criminal defendants.

The post-accident investigative process in Brazil has been marred by conspicuous public confusion of political, military, corporate and personal interests in 'spinning' facts, coloring details, broadcasting unsubstantiated accusations and meddling with the methods of investigation. Few serious observers - with access to information made public - would imagine the investigations have been either fair or thorough.

Under such circumstances, one can see some reason for concern on the part of the pilots that they might be caught in the middle of a political show trial, with objectives other than fairness and fact-finding.

One can also note that the referenced FAA advisory circular, inconspicuous as it is, creates an official standard of plausible deniability for the Embraer crew, in regard to the primary allegation floated about in Brazil - that the crew intentionally disabled the transponder for unspecified reasons. Presumably the FAA kept good notes on the instances and sources indicating the inadvertent shutoff problem they describe in their official circular, so the net effect is to create a strong affirmative defence for any and all claims related to the Embraer crew responsibility for the transponder outage that may have been a factor in the aerial collision.

Certain facts clarified, plot thickens.

[bubbers44]

I do not think the pilots should ever return to Brazil because they can not expect a fair trial. We all know they followed the rules and did nothing to cause this accident. Maybe design flaws in their aircraft caused the transponder to go to standby but they didn't design the aircraft. Going back there would be a big mistake. When ATC puts two aircraft on the same airway at the same altitude with GPS accuracy in opposite directions bad things happen. TCAS was not designed for separation of normal traffic, it was designed to avoid a mid air if ATC screwed up. If it quit working it does not take the responsibility off of ATC.

[green granite]

I do not think the pilots should ever return to Brazil because they can not expect a fair trial.

The problem is of course if they don't return, then the next time something like this happens, the people involved will not be allowed to return home until after the trial which may be years.

[barit1]

If Brazil won't adhere to ICAO norms re impartial safety-oriented accident investigation, why isn't an international boycott by all aircrew a good response?

[A310driver]

barit1

Spot on!

[bubbers44]

Absolutely. No one should be put at risk down there if a mishap puts you on trial as a criminal. Boycot Brazilian airspace if necessary.

[lomapaseo]

If Brazil won't adhere to ICAO norms re impartial safety-oriented accident investigation, why isn't an international boycott by all aircrew a good response?

Simple solution but it never works in a free society.

Where do you draw the line?

Lots of countries besides Brazil have not adopted in full the recommendations of ICAO Annex 13. I take it that you are really paring down the concen only to the criminal part of the investigation and threat of punishment to the flight crew. Else we could add in any criminal investigation leading to punishment of any person including the countries own citizens.

Individual actions by a crew member to refuse to fly a route to such a country are sure to result in unwanted results. So how do you take this up several notches to include all international pilots?

The only way that I am aware, is IFALPA and they were already a non-voting party to the latest ICAO Annex 13 deliberations.

[A310driver]

Unfortunately, this no longer can claim to be the worst air disaster in Brazilian history .

[Brian Abraham]

Just off the press from Avweb

Brazilian Congress Blames Legacy Pilots For Midair

An inquiry conducted by the lower house in Brazil's Congress just concluded U.S. pilots Jean Paul Paladino and Joseph Lepore, who were flying the Embraer Legacy operated by U.S.-based ExcelAire during a midair collision last September with a Gol Transportes Aereos Boeing 737-800, are partially to blame for the fatal accident. Meanwhile, another congressional inquiry, along with an investigation by Brazil's accident investigation team, continues. The completed report found Paladino and Lepore were insufficiently trained in operating the Legacy and negligently disregarded ICAO and Brazilian aviation regulations, engaged in "imprudent handling of the aircraft" and had "poor situational awareness." The inquiry concluded the two pilots should be charged with involuntary manslaughter by having placed an aircraft or vessel at risk. Additionally, the inquiry determined three air traffic controllers had committed the same crime, while one controller should be indicted on voluntary manslaughter. The two pilots and three controllers could face sentences of up to 12 years; the lone controller faces up to 20 years.

Yet the Brazilian Congress' report -- established to look into existing problems with the country's ATC system and corruption, as well as the midair collision -- has come under fire, especially from the body's opposition party. Critics of the filed report point to a lack of technical expertise on the part of those supposedly elected officials lacking an industry background and conducting the inquiry. No timetable was set for the Brazilian Senate to complete its inquiry; the third investigation, being conducted by Brazil's Centre for Investigation of Aeronautical Accidents (CENIPA), is expected to be finished by late August or early September.

[A310driver]

Short Term Solution

All pilots plying the Brazilian airspace should heed the advice of Barit1 in the post of 16 July above. Mere mortals should not venture where angels fear to tread.