Mid-air collision over Brasil

[alemaobaiano]

Originally Posted by 410

Yes Huck, I have to say a similar thought crossed my mind. I thought it sounded awfully like someone in officialdom preparing the ground for a "It wasn't our system that was at fault" defence.

Right, and they are doing that by acknowledging the real possibilty of a lack of ATC coordination between two centres as one of the contributing factors?

Despite what you may think, Brazil follows all of the ICAO norms of accident investigation and the causes of this tragic event will come out at or before the end of the 90 period originally stated. Nobody will hide anything and nobody will cover up anything.

As for a corporate pilot not forgetting who's in the back, who knows where the idea for the alleged test profile came from? If it happened, the idea is unlikely to have originated from the front seats.

[weasil]

U.S. pilots' passports seized as Brazil crash probed

RIO DE JANEIRO, Brazil (AP) -- Two American executive jet pilots were ordered by a judge to stay in Brazil while authorities investigate whether they caused a midair collision with an airliner that crashed into the Amazon, killing all 155 people aboard.

A Brazilian newspaper reported that the pilots' Legacy jet, which was carrying seven Americans, disobeyed an order by the control tower to descend to a lower altitude just before coming into contact with Gol airlines Flight 1907.

http://www.cnn.com/2006/WORLD/americ....ap/index.html

[PlatinumFlyer]

Joe Sharkey was interviewed by Matt Lauer on the Today show about an hour ago. He added nothing to what was in earlier interviews. He mentioned that he was "sure" something hit them and that they did not hit anything. Also, that "we need to be careful in judgement as the two guys down there are in some peril".

There was a graphic display of the accident showing the Legacy approacing form the bottom and to the left of the 737 (when viewed from the 737). Both planes banked (Legacy to the right, 737 to the right, and the Legacy winglet then hits the 737 left wing and the 737 goes into a spin around its center axis and continues that spin all the way to the ground. There was no mention of where this diaplay came from.

[Sky Wave]

Question from a wannabie

You are under positive radar control within Controlled Airspace at FL370. You've filed a flight plan that says you will descend to FL360 at a set point in order to comply with the airway altitude routing requirements.

Is it your responsibility as the commander to request that descent to FL360 or can you assume that ATC is happy for you to maintain FL370 if they do not request that you descend?

Secondly if this is a case of a radio failure, does Brazil have any local instructions which amend the ICAO requirement to maintain your last assigned heading and altitude for 20 minutes before resuming your flight planned altitude and route?

If ATC could not contact the Legacy should they have assumed an RT failure and assumed he would continue at FL370 for 20 minutes and therefore vectored the 737 out of the Legacy's way.

Surely in CAS the commander of the Legacy cannot descend to FL360 without authority from ATC so if they had RT difficulties it's seems perfectly reasonable that the Legacy would maintain FL370.

Is it possible then that the Legacy had some kind of intermittent avionics problem which was switching off the transponder and disabling the radios? Teething problems on new aircraft are not unheard of.

I’d be interested in any positive feedback to the above questions (I may be missing something in my interpretation of the requirements following an RT failure.)

Cheers SW

[lomapaseo]

Originally Posted by Pom Pax

I suggest that there does not have to have been any actual physical contact to have caused this accident.
On the road you meet a large lorry at a closing speed of 150 knots. As you pass your car experiences a severe buffet. Now consider 2 aircraft of similiar comparatives sizes closing at 6 times that speed. V squared has become much much greater. The winglet is subjected to this sudden force in the opposite sense (direction) to which it is designed to work, it fails strikes a glancing blow to the tail plane.
Back to the motoring comparison, Ranger One much earlier in the thread (post #178) made some calculations, that winglet now has as much energy as a very large car traveling at 40 mph. The winglet now strikes the the 738. Now refer to the Lockerbie (Pan Am) report to see how damage to 1 panel of the skin leads to the failure of others.

The Pan Am Lockerbie was not just the one panel of damage that led to its destruction nor even the rapid decompression following. The critical ingredient was the same as TWA800 and that was structural damage in the pressence of reverberating overpressure

I believe that large transport aircraft can easily sustain large sections of skin damage as well as decompression, but not overpressures

[20driver]

offsets

410 and others
I got the geometry wrong and I did read the other discussions. My question is it seems this could be done by the airlines with no official ICAO action required by adding the offset to their SOP's. Not knocking ICAO but it will take years. So back to the question, is there a reason the airlines cannot do this on their own?
With the growth in air travel all over the world and the increased Nav precision this sort of event will happen again. Interesting that this event and the one off Africa took place in the 'empty quarters" of aviation.

20driver

[RiverCity]

A corporate pilot never forgets who he's got in back.

Let me bring up an admittedly ancient, but perhaps relevant, example of just this situation. You have a new owner, plus a Big Wheel from the manufacturer flying over Nowhere and one, or both, want to see what the machine will do and perhaps impress the journo. So they order the pilot who says, "NO!" and then put enough pressure on him so he says, "This is definitely against my better judgement," and gives in for a few fateful minutes.

Let's go back to the Titanic. Excellent captain; owner on board, who wants to show off the ship. Captain tells him there is ice ahead; owner says, keep 'er going. Ship rolls over iceberg, slices bottom open. Captain wants to stop so pumps can keep it afloat longer; owner says, "Keep going." Prevails on captain and causes the ship to take more water and sink faster.

The people in back could have had some bearing.

[Ranger One]

Originally Posted by lomapaseo

I believe that large transport aircraft can easily sustain large sections of skin damage as well as decompression, but not overpressures

Aloha 243

R1

[st2en]

Wake turbulence

I have read with great interest the many postings regarding this tragic event.
There seems to be general agreement that the two aircraft, which were flying in exactly opposite directions, either collided or passed each other very closely.
I am "just" a PPL, but I do think that there is one aspect of the above collision or near-miss theories that is left out... wake turbulence
Assuming that the EMB passed right underneath the 73 on an opposite course, it would have been flying right in the wake turbulence of the 73, which I believe must be rather considerate. Wouldn't that have caused significant problems for the EMB or at least made an impression on the journalist, who does not mention anything along the lines of violent turbulence.

[lenstrad]

strange very strange

but black boxes and flight data recorders do not fail , lets wait , please

[172driver]

Originally Posted by RiverCity

Let me bring up an admittedly ancient, but perhaps relevant, example of just this situation. You have a new owner, plus a Big Wheel from the manufacturer flying over Nowhere and one, or both, want to see what the machine will do and perhaps impress the journo. So they order the pilot who says, "NO!" and then put enough pressure on him so he says, "This is definitely against my better judgement," and gives in for a few fateful minutes.

Assuming for a minute he did that (which, I hasten to add, I do not believe) - would he be doing so on an airway ??

[RiverCity]

Assuming for a minute he did that (which, I hasten to add, I do not believe) - would he be doing so on an airway ??

Since we're all theorizing here (see lenstrad's comments), I thought I'd toss that in. I assume the box will indicate if either altimeter had been set correctly, thus perhaps making either pilot assume incorrectly there was no traffic ahead of them (and the bizjet assume a little demonstration could be carried on quite safely at his altitude). You are dealing with what I assume are two flight decks full of very professional pilots who aren't going to take chances unless their instrumentation gives them false readings.

I keep wondering about that "shadow," that "thing" the bizjet saw above him.

[KC135777]

I hope these two pilots get a fair shake. From the excerpts of this article, it looks like they're already looking for a scapegoat....Tag, you're it ! :-(
What a bunch of crap.
____________________________________________________________ _

Brazilian authorities believe two pilots may have shut off the transponder in their business jet, rendering its anti-collision system useless,
"We know that the transponder was turned off," said Jose Carlos Pereira, the head of Brazil's airports authority, the Estado De Sao Paulo newspaper reported on Wednesday...."A pilot only turns it off when he doesn't want to be identified. The Legacy could have turned it off to try some air tricks far from the eyes of the air traffic controllers," Pereira said.

Pereira of Brazil's airport authority, who was also a military pilot, told Estado that Gol's Boeing 737-800 was probably being flown on automatic pilot and closely adhering to its set altitude.

"The Boeing is like a bus. It never leaves its route," Pereira said. "With the automatic pilot its altitude varies at most by one meter."

[RiverCity]

There was no maneuvering by the legacy bizjet. Here's the journalist's article.

I'm willing to believe that; as I said, we're all speculating, even the most experienced of us are coming up with scenarios that the black boxes will affirm or negate. However, if your admission of such were to result in someone's offing, would you say anything? I'd leave all witnessing to the black box and the pilots. I'd say nothing but praiseworthy statements. They got the CVR and the FDR.

[BOAC]

PLEASE do not keep on reposting the NY Times article. It is at Post #256.

[chuks]

I find it amazing how much wild speculation goes on here over crashes when a bit of patience should see all the questions answered.

Just think how you would feel if you were being held, under suspicion, with your fellows here mulling over what you might have got up to that would cause the deaths of over 150 citizens of the country that was holding you.

When I read that the crew admitted doing something illegal all I could think was, 'Oh, sure.' You think someone would be unprofessional enough to do something like turn off the transponder and play around on an airway but then ADMIT to that? That doesn't make sense on the face of it. Either you play it straight and tell the truth or else you screw around and lie about it. To first screw around and then play it straight is not normal behaviour, so that quote seems unbelievable on the face of it.

It sure is strange to see this relatively small, lightly damaged Embraer and the relatively large, crashed 737; a logical explanation is hard to come up with and that makes all the more reason to just wait for the official report, when they can use the CVRs and FDRs to tell us what really happened.

We went through this once before in Nigeria when that 727 was sent out of control in response to a TCAS RA. We had eyewitness reports of the aircraft 'hovering' at Murtala Muhammed Airport, from a man of the cloth, no less, 'inside' information that the previous crew had refused to fly the accident aircraft because it was unsafe, that an engineer had been seen working on the hydraulic flight controls just before it departed on its ill-fated flight and so on. The final report was a real anti-climax; who would have guessed that the crew could have lost control in such a way? But there it was. This one might be like that, something we wouldn't have thought of initially.

I find the reports from Brazil to be useful. The speculation less so!

[westhawk]

Originally Posted by chuks

I find the reports from Brazil to be useful. The speculation less so!

I found the rest of your post to be reasonable and pertinent. But considering the unsubstantiated and speculative statements in the Brazillian "reports" thus far quoted, the above statement might merit re-consideration.

Perhaps if you meant to convey that the reports from Brazil were useful in demonstrating the pure folly of treating initial press reports of any tragic event as fact, I might agree!

Objective data does exist, and will eventually become available to us. Your advice regarding patience is well founded, difficult as it may be to follow.

Best regards,

Westhawk

[ATC Watcher]

Originally Posted by threemiles

There is always a danger in this thinking when not anticipating that loss of radar contact or comm failure may occur at some point. Exactly the same thinking was bringing the TU-154 and C-141 down.
Away from high dense airspaces and with the exception of the oceanic rush routes it is good practice to stick to semi circular rules over long thin traffic routes. No reason to not do so.

Things have evolved a little since introduction of radar in 1960. ATC radar Clearances today do not anticipate loss of radar . If that comes , emergency procedures, like 500 ft emergency separation, will try to save the day.

The 154/141 Namib collision you are refering to was outside radar coverage and the 154 was not talking to anyone , outside his original flight plan route , and probably ( we will never know) did not dare to change Altitude on his own initiative. There was no ATC intervention there.

In long thin procedurally controlled routes, semi circular makes a great deal of sense, I fully agree, but in our case here in Brazil, both aircraft were under radar control.
The reasons for (radar) ATC to deviate are many, the most common are intermediate level off ( in climb and descent), expediting other traffic thru a level, turbulence avoidance, complying with a local flight allocation scheme or an adjacent centre requirement to name a few.

Just think of 2 airways converging /crossing with 30 degr Westward , possibly even coming from 2 different units. You are of course going to use all levels at your disposal to solve the cruising conflicts , not only the even ones.

[jondc9]

I saw a report quoting a brazillian official (reuters report) that the transponder was off.
anyone with data on that?
jon

[meatball]

Most Alarming News

Heard from 2 northwest pilots today in montreal that the american pilots have not only had their passports retained, but that they are under arrest. Why ? Because they were flying at the wrong flight level for the direction of flight, off the airways and DID NOT HAVE THEIR TRANSPONDER ON, meaning that they had no TCAS availability. It could be baloney, could be true,but THEY clipped the GOL 737, not the other way around.......