I couldn't find the last thread but thought it was time for a new one anyway since I just found interesting new developments:

Today a Brazilian Airforce R99 AWACS aircraft located the severed wings of the GOL jet miles away from the main impact site. Military personell arrived on the scene shortley afterwards and it has now been confirmed that the left wing was ripped off the aircraft

*article in Portuguese*

http://www.uai.com.br/uai/noticias/agora/nacional/265659.html

A high ranking official from the Secretary of Defense confirmed that the Legacy's winglets acted like a sharp knife going through butter when it sliced the GOL's wing off. This caused a near free fall of the 737 from 36k feet. The same report also states that most passengers were probably unconscious at time of impact due to the depressurization of the aircraft.

This article, also in Portuguese

http://www.uai.com.br/uai/noticias/agora/nacional/265658.html

states that the Legacy flew for 50 minutes without being in contact with ATC; and confirmed that the transponder was off. CINDACATA 1-Brasilia Center- tried various times to contact the Legacy to instruct them to fly their assigned altitude AND turn on their transponder. This has been confirmed by various aircraft who were on that same frequency that day; the Legacy pilots never made contact with ATC until they declared an emergency; at which point the transponder came back on squwking 7700.

An airborne laboratory Hawker Siddeley 800 of the Brazilian Airforce flew multiple test flights at the exact location of the collision and determined that all ATC equipment are 100% operational and not disfunctional.

That same report stated that the Legacy utilizes the most modern TCAS system in use today, the TCAS 2000 which detects airborne aircraft as far as 120 km away. If the transponder were to experience a mechanical problem a backup system would activate automatically. According to senior officals, this makes the possiblity of a transponder failure impossible. Only turning it off manually would result in a complete transponder/TCAS shutdown.

[Edited 2006-10-08 00:53:06]

[Edited 2006-10-08 00:54:39]

[Edited 2006-10-08 01:10:43]

This accident is getting stranger with every news report. Why would they turn off the transponder? Sounds kinda fishy. But anyway, it is now officially confirmed that there was a mid-air collision?

Quoting Varig (Thread starter): According to senior officals, this makes the possiblity of a transponder failure impossible. Only turning it off manually would result in a complete transponder/TCAS shutdown.

There is, however, an AD that affects Embraer aircraft transponders (as well as others). The issu is not a malfunction, but something that could accidentaly put the transponder into stand-by mode, which would not alert the TCAS.

Link to AD:
http://www.tdatacorp.com/iaprch/06-19-04.htm

PS: This is part 6 btw.

Hi Varig,

Thanks for the update. Since the Brazilian Airforce tested the radio coverage within the area, is there any explanation on why the 737 was not contacted???

To my best knowledge, we were not sure why the 737 was not contacted when the Legacy did not respond to the ATC, but it was debated that poor radio coverage could be to blame.

mbg

I have been asking and wondering that same question mbg. My best guess is that the CINDACATA 1 controller never contacted the CINDACATA 4 controller-the center GOL was in contact with-to relay the information.

Instead they repeated their attempts to get through to the Legacy pilots; probably unaware themselves the Legacy and GOL were on a collision coarse.

Note that the CINDACATA 1 controller had no idea what altitude the Legacy was flying since they were not receiving any info from their transponder. Thus they had no way of knowing the jet was flying at the same altitude as the 737. They simply repeated multiple times to the Legacy their assigned altitude, 37k feet, and requested that they turn on their transponder. No communication was ever received until after the accident.

Those pilots are definitely going to prison. And that's if they're only guilty of accidentally leaving the TCAS and the transponder and the damn radio off for forty minutes. If it was all switched off on purpose cos they were up to some kind of no good, who knows where this might end.

The AD from the FAA raises an interesting point. If you take longer than 5 seconds to change the squawk code, the transponder switches to standby mode - although it would appear to be switched on to the crew and there would be no TCAS fail indications on the EHSI. After the collission ATC reported that they picked up the Legacy on secondary radar squawking 7700. Before the collision all they were getting from the Legacy was a return on the primary radar showing the approx position of the Legacy. The simple act of changeing the squawk code from the allocated to the 7700 emergency code would have been enough to wake the transponder from it's Standby state.

Would the Legacy have been given a Squawk change while flying enroute over Brazilian airspace, or would it have retained the initial Squawk code that had been issued to the aircraft before take off?

Quoting McG1967 (Reply 6): Would the Legacy have been given a Squawk change while flying enroute over Brazilian airspace, or would it have retained the initial Squawk code that had been issued to the aircraft before take off?

Would there be any reason to change it when they crossed BSB (the point where they were supposed to switch from an odd-numbered FL to even)?

Quoting Varig (Reply 4): I have been asking and wondering that same question mbg. My best guess is that the CINDACATA 1 controller never contacted the CINDACATA 4 controller-the center GOL was in contact with-to relay the information. Instead they repeated their attempts to get through to the Legacy pilots; probably unaware themselves the Legacy and GOL were on a collision coarse.

Another reason for which CINDACATA 1 did not attempt to contact the Gol airplane is because the Gol B737 was still in CINDACATA 4 control zone and has not been transferred to CINDACATA 1. The CINDACATA 1 controller probably didn't even know about the existance of the Gol aiplane. All he new was that there was a Legacy with his TCAS off, and probably at wrong altitude.

I hope we hear the results from the 737 black box soon!

Airbrasil

Laura Brown, a spokeperson of the FAA, stated that the Legacy's transpoder was NOT the same one in the AD, so it should had been working fine.

Link in Port. only:
http://oglobo.globo.com/pais/mat/2006/10/07/286024963.asp

[Edited 2006-10-08 04:38:50]

Quoting Katekebo (Reply 8): Another reason for which CINDACATA 1 did not attempt to contact the Gol airplane is because the Gol B737 was still in CINDACATA 4 control zone and has not been transferred to CINDACATA 1. The CINDACATA 1 controller probably didn't even know about the existance of the Gol aiplane. All he new was that there was a Legacy with his TCAS off, and probably at wrong altitude.

My question was why the CINDACATA 1 controller did not contact the CINDACATA 4 controller directly. I know he can't contact an aircraft out of his airspace but he can contact the controller to advise of the situation.

But like I said, Brasilia Center had no way of knowing the Legacy's altitude or that it was heading straight for a 737 in cruise flight.

And no, there would be no reason to change squawk codes once in-flight even if you are switching Center frequencies and/or waypoints. But like PPVRA pointed out that AD didn't apply to Legacy aircraft anyways. I am really anxious to hear info on both CVRs and FDRs.

Quoting Varig (Thread starter): Today a Brazilian Airforce R99 AWACS aircraft located the severed wings of the GOL jet miles away from the main impact site. Military personell arrived on the scene shortley afterwards and it has now been confirmed that the left wing was ripped off the aircraft

Am I dreaming or was there not photographs of releatively intact wings on a previous thread. How come the Brazillian Air Force have now discovered a "severed wing" somewhere else? What are we not getting??

They found the actual part of the outer wing that was sliced off by the Legacy winglet. What you have been seeing on various photos are the center wing box and landing gears.

If all this turns out to be true I really hope the pilots are persecuted to the fullest extent of the law and serve a long, looong time in prison. Even in the even the transponder did malfunction, which doesn't seem to be the case as it has been stated the transponder model is not the same as in the AD, the pilots failed to respond to 40 minutes of radio commands which to me shows a complete lack of respect for ATC authority or just simple carelessness. Granted, all this could have somehow been an accident on the Legacy crew's part, but from the information presented at the moment, it unfortunately doesn't seem like it. Their failure to conduct their flight safely and in a procedurally found fashion resulted in the death of 155 people and they should really be made to pay the price. I do agree that the situation is extremely fishy because it still strikes me as absolutely dumbfounding that two pilots could blatantly ignore everything they have been taught. Maybe there is something more to this?

I thought that all civilian aircraft fitted with a transponder by law had to have it on?? Am i mistaken?
Thanks
A320ajm

This is the first thread I've read on this subject, so forgive me if this has been mentioned, but in this day of hightened security, how come an aircraft is allowed to fly for 40 minutes without radio contact, without being intercepted? Or were they just gonna wait to see where it was going first and scramble the jets when it was too late?

EDIT: Just been thinking about it. I guess radar coverage in that part of the region is non-existant? Hence they didn't know where the bizjet was?

[Edited 2006-10-08 11:28:38]

Quoting Sean377 (Reply 16): Just been thinking about it. I guess radar coverage in that part of the region is non-existant? Hence they didn't know where the bizjet was?

Radar Coverage i believe is existant, not sure of the quality and acuuracy.

Good question tho, why where jets not scrambled, maybe it was due to it being over the jungle and no high pop area. if it wasa flight inb to say London, i dam hope that fighters would be scrambled

Quoting Thomson735 (Reply 17): maybe it was due to it being over the jungle and no high pop area

Best place to intercept if you ask me. Well, best place to shoot it down, if that were needed!

My guess is that the Legacy crew were playing with their new toy and showing their pax what they were able to do with it. Same happens when you buy a new car or a new whatever.
Just my guess though

Quoting Icaro (Reply 19): My guess is that the Legacy crew were playing with their new toy and showing their pax what they were able to do with it. Same happens when you buy a new car or a new whatever. Just my guess though

...or they simply forgot to turn the tcas on and won't admit it?!

I really cant believe that any pilot would intentionly turn the Transponder off, its a crazy thought.

When i think of a cause i often then try to think of why would they do that, and i cant think of any reason for a crew to turn the transponder off except maybe if they didnt want to be seen aswell yet lol i cant think of why theyd wanna do that either

I wonder what angle the collision occured that one plane sheared off the wing of another. How could the pilots of the Legacy not know they sheared off the wing of a 737?

The wing of any airplane is the strongest part of it's structure. I'm having a very hard time believing that the Legacy's plastic or composite winglet could "slice off" a 737's wing. Some chain of events caused an inflight breakup of the 737, and I'll wait for the investigation to prove exactly what.

Well from the picture below, it looks as though both wings are in the viscinity of the main crash site. Could they have meant the left vertical stabiliser and elevator?



(Photo: Sebastião Moreira/AE)

Could it have been possible that the GOL crew, in trying to avoid the other aircraft overstressed the B737 and that caused a structural failure besides the damage from the actual collision?

The FDR and CVR should be able to shed light on this.

Quoting Thomson735 (Reply 17): Quoting Sean377 (Reply 16): Just been thinking about it. I guess radar coverage in that part of the region is non-existant? Hence they didn't know where the bizjet was? Radar Coverage i believe is existant, not sure of the quality and acuuracy. Good question tho, why where jets not scrambled, maybe it was due to it being over the jungle and no high pop area. if it wasa flight inb to say London, i dam hope that fighters would be scrambled

Yes, there is radar coverage. It's a brand new system, too, and before there were no coverage at all - pilots kept that region safe by flying strictly their flight plan and radio contact with ATC.

I've thought about why they did not scramble aircraft. Well, they weren't suspicious for one (keep in mind that the Brazilian military is probably (looking out for drug traffic and they are in that mindset). Also, the Legacy had a scheduled stop in MAO, so why scramble any aircraft now?

Can it be that the pilots set a wrong frequency ? How they can not answer the ATC call attempts for around 40 minutes ? Very strange, because this is as it looks not only confirmed by ATC, but also from pilots who were in this region during that time. So fact is they not replied, plus switched off the transponder and flew an flight level which was not assigned to them. I think this is against all rules of flying what the guys did there.

Quoting Jbguller (Reply 24): Well from the picture below, it looks as though both wings are in the viscinity of the main crash site. Could they have meant the left vertical stabiliser and elevator?

Look carefully at the left wing, it HAS failed. What you are looking at is the lower skin only and bits of the leading edge. You can tell because you can see the ground through all the missing access panels.


T prop.

Quoting Kellmark (Reply 25): Could it have been possible that the GOL crew, in trying to avoid the other aircraft overstressed the B737 and that caused a structural failure besides the damage from the actual collision?

Yea im thinking along these lines aswell, the Term "sliced" the wing from the 737 is maybe innacurate, but im sure the legacy caused sufficiant damage to the wing to cause it to break up at some stage

Thomson735

Quoting Icaro (Reply 19): My guess is that the Legacy crew were playing with their new toy and showing their pax what they were able to do with it.

IMHO I agree. This sounds a lot like the Pinnacle/Northwest Airlink CRJ 200 that crashed in Missouri in 2004 because the pilots were screwing around on a ferry flight. I know the results of this crash are still preliminary, but from what I have learned on A-Net, that seems to be the cause.

http://aviation-safety.net/database/record.php?id=20041014-1&lang=en

First, yes the Amazon region of Brazil does have extensive radar coverage. It is controlled by a system known as SIVAM

http://en.wikipedia.org/wiki/Sistema...e_Vigil%C3%A2ncia_da_Amaz%C3%B4nia

and is one of the most modern radar programs in the world. Plus it has been determined that all ATC and radar equipment were 100% funtional on that day.

Second, it is not hard to imagine a winglet slicing a wing of a 737 off at all. The wings of an aircraft are realtively fragile when compared to the rest of the plane and not to mention thin. Plus, physics would tell us that an object with a distinct angle-such as a winglet-when scraped against a moving surface, and those two moving objects were moving at a combined airspeed of over 700 knots, all this would at the very least cause the structure to loose its integrity, in other words it would slice a gash into it.

At that point it would only be a matter of seconds for the rest of the wing to come apart from the point of contact outward. On another note investigators are looking into the probabilty that the Legacy pilots turned down the volume of their COMM radios on purpose so as not to be bothered by ATC. This would explain their not answering the controllers for 50 minutes. It has been confirmed that following the collision the pilots made contact for the first time in almost an hour and began squawking again on the emergency code.

As to why no fighters were scrambled, it is hard to say but my guess is that the threat from the Airforce's point of view was low. First, the aircraft was on secondary radar the entire time-albeit they had no idea at what altitude-and had no reason to suspect a hijacking. Plus as PPVRA pointed out the Legacy had a scheduled stop in Manaus coming up.

Second, all this happened over a very sparsely populated region. Had all this happened over a metropolitan area or especially over the capital of Brasilia then interceptors would definently have been scrambled.

That is what happened in 1989 when a VASP flight on its way to Sao Paulo from Belo Horizonte was hijacked by a man who wanted the Captain to fly it into the Presidential house in Brasilia. Within 15 minutes of the Captain squawking 7500 2 fighters were escorting the 737, ready to shoot it down should they receive the order.

[Edited 2006-10-08 19:35:02]

Quoting Varig (Thread starter): the Legacy flew for 50 minutes without being in contact with ATC; and confirmed that the transponder was off.

Are we talking about pilot negligence here??

I'm a Pilot my self and I can't Imagine being 50 minutes without contacting the ATC, I can understand that the transponder don't work but failure to communicate to the ATC seems very strange.

Negligence is paid with jail time, I hope this is not the case with the legacy pilots.

I'd tend to agree with Jbguller.

Even if a good portion of the 737's left wing was sheared off by the WINGLET of the Legacy, which i have a very hard time believing, the plane would have a relatively good chance of survival (think of the DHL A300 that was hit by a missile over Iraq and had a fair chunk of its wing mangled). But if the elevator/horizontal stabilizer was sheared off, all pitch control would be lost, and it would make sense that it would enter the "freefall" that was mentioned earlier. It would also be much more credible that the Legacy's winglet could critically damage the smaller horizontal stabilizer and not the craft's actual wing.

What I don't understand is how the pilots/passengers in the Legacy did not realize that they had just clipped a 737. Also, I'm not positive, but weren't the two going on exact opposite courses? If so, it would be physically impossible for the Legacy to clip the 737's horizontal stabilizer from that angle as they would have hit the main wing or fuselage before (clipping the wing would still be possible), suggesting that a composite winglet on a business jet sheared off a piece of an extremely sound metal composite 737 wing.

To me, this is starting to seem like an extremely unfortunate chain reaction, typical to most major aviation accidents. I doubt that the Legacy pilots turned off their transponder intentionally (any benefits from doing so?), and I'll bet we'll find that the Legacy, at fault of its pilots and ATC, disabled the 737's elevator, rendering it uncontrollable.

Just my   

-Regards

Tom

I did forget to mention that the investigators did indeed state that there is a high probability the horizontal stabalizer was also sheered off by the same impact, but they have not confirmed this yet.

If all this is true I find it hard to believe that the Legacy pilots did not see what they hit. They would have seen much more than a shadow as they claimed. That could be a cover up on their part...we shall find out for sure from the CVR recordings.

Let me add a little fuel to the fire:

1) As I understand it, this was a new Legacy with very few hours on it. New airframes from any manufacture frequently have issues with them, as is to be expected from anything handbuilt containing thousands of parts. Systems failures are common in new planes, including radios. Could the cannon plug from the radio have failed? How about the transponder? I assume the investigating authorities will check the Legacy over, but I have seen failures in new aircraft (A Gulfstream IV) where the cable lines were so tight, that when the airplane was pressurized it streched the airframe just enough to disconnect COMM1, and when it de-pressurized, COMM1 came back on-line.

2) Winglets on most aircraft are not that strong. In fact many simply bolt on and have little structural integrity. I'm not a engineer, but I have a hard time buying the argument that a Legacy winglet could slice through a 737 wing like butter. The entire leading edge of a wing has to be built to withstand a hail storm, and somehow fist size balls of frozen water seem to sound worse than a hollow thin aluminum (or even fiberglass) winglet. Are there any engineers here who can lend some true expertice?

3) The unusual attitude theory. Based on the fact that the winglet and the end of the horizontal stab of the Legacy were damaged, a logical argument stands that the 737 was at a significant angle of bank, and that one wing of the 737 hit both the horizontal stab and the winglet. That would indicate about a 45 degree bank angle. Similar to a steep turn. This would make sense if the captain of the GOL flight saw the Legacy at the last moment and attempted to manuver in a radical fashion. Remember, the autopilot would have to be disconnected first (red button on the yoke) then a hard turn of the yoke to start the turn. Could this have concluded in an unusual attitude? And could this unusual attitude have led to an unrecoverable situation? THe black box would provide answers. Another question, could the pilot of the GOL flight overstress the controls, leading to control failure? ITs amazing how much force a person can put into a control when they fear a colision.

Thoughts?

Are you saying hail is stronger than winglets? If so there must be a lot of winglet repairs.

Hail can do a lot of damage to aircraft.

Imagine something as heavy as a winglet coming at the speed as in this case...

There was a case many years ago where a Swedish Air Force fighter had a collission with a bird in high speed. The bird (soft..) went thru the canopy and ripped the shoulder of the pilot.

/JM

I agree that only an aeronautical engineer would could tell us for sure. Since I'm not one, and as far as I know the rest of us are'nt either, then we really don't know if a winglet can do that to a wing.

That is however the current statement from the ongoing investigation, which I'm sure is composed of various aeronautical engineers including EMBRAER ones. But I would love to hear some insight from anybody on here with engineering experience.

As far as overstressing the 737, that is an almost certainty AFTER the collision. But overstressing the plane during evaisive manuvers seems unlikely.

Once spotting the Legacy the GOL pilots probably had less than 5 seconds to disconnect the Autopilot and take evasive action. Almost immedietly the Boeing was hit. That is not enough time to manuver a 737 in such a way that would overstress the airframe enough to rip the wings off. The steep turn the 737 had time to do was definently within the operating limitations for the aircraft.

But then again that is my best guess based on information we have been given and my own experience as a pilot myself.

Strange, to say the least. The transponder not working has nothing to do with ATC communicating with the Legacy verbally,unless there was a glitch. But, given that they were able to contact ATC after the collision, I doubt that was the problem. A missed check-list on the com stack is my guess.

God bless the souls on board. I hope the truth prevails.

I was a traffic controller in France between 1976 & 1977 in Aix en Provence. At that time, we were instructed to watch carefully "conveyed" brand new aircrafts because their pilots had a slight tendency, as said, to play with their new toy (switiching off transponders) and disrespect tarffic control instructions;they used, for instance, to enter military aeras "by mistake". I wonder whether such alerts still exist in western hemisphere or had ever existed here in Brazil (It is a coincidence that I am now living in Brazil).

Judging from what the pictures show of the damage done to the Legacy aircraft, and from what few descriptions have been provided from the Legacy occupants, it is my belief the left winglet of the Legacy aircraft may have either struck the bottom or the side of the #1 engine of the –737 or was ingested by that engine. The former may have knocked panels loose or torn through them in such a manner that the slipstream would have ripped them completely off. Subsequent slipstream agitation could then have caused enough damage to cause the engine to dis-engage from the wing, flip up over the top of the wing, and the wing, itself, fail. The latter could have caused catastrophic failure of the engine blades which, in turn, could have caused the same type of damage.

My thinking is that the horizontal stabilizer on the Legacy tail-plane appears to have struck possibly the underside of the –737 left wing. The relative engine-to-underside-of-wing vertical distance on the -737 corresponds fairly closely with the winglet-to-top-of-horizontal-stabilizer vertical distance of the Embraer 600. This would explain why there is such little damage to the Legacy’s horizontal stabilizer. A second circumstance that it would explain is the Legacy’s ability to maintain substantial flight capability down to landing. This horizontal-stabilizer-strikes-the-737-wing also negates the need to have either aircraft in any other than a straight-and-level attitude.

My .02 worth.

As a former Air Traffic Controller I believe the ultimate responsibility for this accident might lay directly at the feet of ATC.

It is the responsibility of ATC to provide separation of IFR aircraft from ALL other known aircraft, regardless of the flight status of those other aircraft (VFR, IFR, radio- equipped, no radio [NORDO], Mode-C- equipped, NO-MODE-C, etc.)

When ATC has an IFR aircraft that is exiting their Area of Responsibility (AOR) and is entering another sector’s AOR, it is up the “losing” controller to notify the “gaining” controller of the "known flight status" of that aircraft (call-sign, squawk code, altitude, heading, routing, last assigned frequency, etc.) BEFORE the aircraft exits the “losing” controller’s AOR. If the “losing” controller cannot give the “gaining” controller all of the above-noted information, he/she gives as much as is presently known about the status of flight of that aircraft.

If a “gaining” controller sees a NO-MODE-C, NORDO aircraft about to enter his/her AOR, it is up to that controller to find out as much about that aircraft as possible via any means possible. If no contact can be made with the NO-MODE-C aircraft due to it being NORDO, then it is up to that controller to clear all IFR traffic AWAY from that aircraft, either by altitude separation or by course deviations.

Without altitude information on the incoming aircraft, the “gaining” controller would normally issue course deviations only, as he/she (1) does not positively know the altitude of that aircraft, but (2) can see it’s general course.

If CINDACTA 1 informed CINDACTA 4 that the Legacy was NORDO and NO-MODE-C, then CINDACTA 4 should have turned the Gol -737 to obtain horizontal separation.

If CINDACTA 4 was NOT in contact with the Gol -737 then all bets are off, since BOTH aircraft would be NORDO. About the only thing left to do would be for CINDACTA 1 to instruct the Legacy (in the blind) to do a turn to the right, and CINDACTA 4 to tell the Gol -737 (in the blind) to do a turn to the right (20 to 30 degrees would be sufficient, depending, of course, on how far apart the aircraft were at the moment the turn was initiated.)

A question that begs to be answered is this: If other aircraft could hear CINDACTA 1 trying to contact the Legacy, and could not hear any reply, did THEY try to contact the Legacy to act as relay (with permission of CINDACTA 1, of course.)

Jerald,

The Legacy was actually still under CINDACATA 1 control, although it was near the CINDACATA 4 hand-off area at the time of impact.

I have actually been wondering the same thing as you but in a different way. As you may know ATC controllers have the capability to communicate with other ATC controllers and infact do that often. I have been wondering why the Legacy controller didn't contact the CINDACATA 4 controller and advise of the situation.

On the other hand, in their defense, ATC had no reason to suspect that the Legacy was flying anyother altitude than that assigned to them and filed on their flight plan. There was no way to know the 2 aircraft were on a collision coarse. Still, I would liked to have seen maybe better communication between the 2 Centers...but that does not excuse the possible mistakes made by the Legacy pilots.

[Edited 2006-10-09 02:25:15]

You are right Varig, and partly is also Jerald.
1-As I said, ATC were usually aware of potential danger represented by "conveyed" new planes. If so, lack of contact with the Legacy would have created a general advise in the area. 30 years ago, in Europe, it would. I can guarantee to you.
2-However, despite the fact that what Jerald said is extremely relevant, I cannot agree with his preliminary words "ultimate responsibility for this accident might lay directly at the feet of ATC". The ultimate responsability is always captain's, and when there is no contact with ATC (on purpose or not), fact that the Legacy pilots admitted, there is no doubt about it.

Michel

"Ultimate responsibility" was, perhaps, a mis-nomer. "Entity of last capability" may have been more accurate, and that would belong to the last person / entity that could have prevented an accident, no matter what conditions existed prior to the accident.

We do not hear anything about what voice communications there were with the -737, nor at what point/time those voice communications were lost. I also seem to recall a post that mentioned there was no Mode C being received from that aircraft as well.

What are the chances that Mode C fails on two aircraft at the same time at just about the same place? Infintisimally small, I would imagain.

Were there other aircraft in the same general area who did not show Mode C?

Was there a problem with BOTH CINDACTA's Mode C receivers at the same time? Again, an infintisimally small chance of that (UNLESS both are fed by the same power source. Not likely.)

And that post about a Brazilian research aircraft checking out the radio / nav systems in the area? (Several days after the accident, incidentally.) Did they use the same TYPE of MODE C equipment as was on the Legacy? Did they fly the same route, at the same time of day, at the same altitude?

Lots of questions. Darn few answers....

One has to wonder about the competency of the Legacy pilots, their perhaps limited experience with this aircraft, experience with it's radio and transponder equipment as well as their experience or lack thereof with the route they were flying. Then there is the possible factor of their attitudes as toward their transponders, radio communications and behavior in those areas. As noted by others:

Quoting Maperrin (Reply 39): I was a traffic controller in France between 1976 & 1977 in Aix en Provence. At that time, we were instructed to watch carefully "conveyed" brand new aircrafts because their pilots had a slight tendency, as said, to play with their new toy (switching off transponders) and disrespect traffic control instructions;they used, for instance, to enter military areas "by mistake". I wonder whether such alerts still exist in western hemisphere or had ever existed here in Brazil

Quoting United787 (Reply 30): This sounds a lot like the Pinnacle/Northwest Airlink CRJ 200 that crashed in Missouri in 2004 because the pilots were screwing around on a ferry flight.

(these guys decided to push the max altitude limits, about 43,000 ft, IIRC, and pushed the envelope, probably ended up stalling out the a/c and unable to get out of it.)

Phatty3374,
There are significant differences between the DHL A300 and this incident.
1. Kinetics
The DHL A300 was hit by the SAM on a relatively obtuse angle in relation to the wing. The damage was spread either by explosion, or the "slope of target plane"... Excessive energy was dissipated by some energy blowing through the wing.
The 738 was hit by a winglet coming in at 800 - 900 KTS, that's about 1500fps... Given the head to head nature of the collision, it would mean that the relative kinetic impact of the Legacy's winglet have to be absorbed by the 738 wing and dissipated. Not much of a "through the wing overblow and dissipation" due to the angle. How does it get absorbed and dissipated? Absorbtion and heat. Now, it might not cut like a knife through butter, but certain things could be damaged, like HYD lines (gotta check some books on the location of these lines on the 738 though), fuel tank (which could lead to runaway gross fuel imbalance between the sides too).

2. Envelope margins
The DHL A300 happened at low altitude, where the manouvering margins are bigger, as th air was thicker. The 738 was hit at high altitude, somewhere near coffin corner anyways. How sensitive is the aircraft at that altitude? Well, a "mild upset" at that altitude could lead to speed loss and stall on the 738 that has resulted in crews to go to Max Continuous Thrust to keep it away from stall in the past... and that's not with a collision, that's just turbulence and ISA temperature deviations. Furthermore, a clean wing is critical to the operating margins at those heights, again, icing (a temporary wing "deformity") could put you behind the power curve and stall you. Now imagine a few skin ripples, rip tears, and a "newly introduced vertical surface" suddenly becoming part of the wing... It doesn't take much to doom it if it wasn't already by then. You don't need the loss of the horizontal stab for the disaster.

Varig,
How they can not realize they just clipped the 737? Come on, pilots don't look outside ALL the time during cruis. They were probably just chatting away to each other. Do you look outside continuously in an IFR environment? They would look at their instruments and chat to each other. They wouldn't know what was coming if the Legacy's transponder wasn't functioning as claimed by some reports.

Overstressing the 738 during the evasive manouver seems quite possible, as the small manouvering margins at those altitudes are thin, but also, at those speeds, small pitch changes, or yoke nudges could already give you noticeable G changes... though more likely the overstressing happened AFTER the collision.

C680,
Your #1 points at some useful insights!

I also doubted that it "sliced like butter"... But it didn't have to slice it like butter to down it.

Your #3 I tend to agree on as a possibility. On the autopilot, a hard force put on the yoke to in reaction to seeing the Legacy would have disconnected the autopilot without pressing the red A/P D/C button on the yoke. And the manouvering margins up there is not exactly large, so an unrecoverable situation would not be a surprised.

*I'm still wondering how many are obsessd with the Legacy having to hit the 738 elevators*

Mandala499

Quoting Mandala499 (Reply 46): How they can not realize they just clipped the 737? Come on, pilots don't look outside ALL the time during cruis. They were probably just chatting away to each other. Do you look outside continuously in an IFR environment? They would look at their instruments and chat to each other. They wouldn't know what was coming if the Legacy's transponder wasn't functioning as claimed by some reports.

No, I don't look outside all the time during IFR. However in VFR conditions you are capable of seeing a Boeing 737 right on top of you I would imagine. At the very least you would *hear* it. But then again I have never had a close encounter like that with any aircraft of any kind so I am no expert. I was just pointing out how that seems unlikely. I say this because while flying IFR I see birds fly near my cockpit all the time and I notice them. Sometimes I even have to turn away quickly to avoid getting too close to them. And these are vultures and hawks....imagine a 737 right in front of you.

As for the evasive manuvers, once again only an engineer or 737 pilot could tell us for sure if the GOL pilots could have overstressed the plane so quickly. But I do know this: abrupt manuvers are within the operating limitations of all aircraft, 737s included. And an abrupt manuver is probably the only thing they had time to do before contacting the Legacy. The FDR will tell us for sure. At this point I am open to any possiblity but I must say things are not looking good for the Legacy pilots.

117 bodies from the Gol flight has been found, 37 still missing.

How much NTSB investigation is going to be done?

Are Brazilian investigations thorough and valid substitutes for what we are used to here in America and other nations?

(This is not an attack on Brazil    )