Brazilian airplane crash between two brand new airplanes

[chracatoa]

A Boeing 737-800 and an Embraer Legacy executive jet would have collided (http://hosted.ap.org/dynamic/stories/B/BRAZIL_PLANE_MISSING?SITE=DCUSN&SECTION=TOP_STORIES&TEMPLATE=DEFAULT) in mid-air, killing all 155 passengers on board the Boeing aircraft.

Any airplane expert here? How can two modern airplanes like those collide in mid-air? The 737 was flying since Sept. 12 and it had 200 hours of flying. The legacy jet was making its inaugural flight to the U.S. (nobody was injured, it landed safely).

On a side note, a conspiracy theory is already brewing. Today is elections day here and some people are saying someone caused the crash to influence the elections (though I have no idea how it would change anything).

[HeavyAaron]

Aircraft collide in mid-air when they attempt to occupy the same space at the same time.

The suprising part of this is that that truth holds independantly of the year of manufactor of the respective aircraft.

Aaron

[IllegalArgument]

Aircraft collide in mid-air when they attempt to occupy the same space at the same time.

The suprising part of this is that that truth holds independantly of the year of manufactor of the respective aircraft.

Aaron

I think he was looking for better answer than that. Why didn't traffic control see the danger?

I don't think, modern passenger aircraft have internal radar. So, my guess would be, the traffic controller screwed up, one of the pilots messed or both.

[HeavyAaron]

I don't think, modern passenger aircraft have internal radar.

Actually, they do.

Aaron

[Rob Lister]

Could be lots of things. Transponders turned off/broken in either plane, ATC goof, ATC equipment goof, yada. Gotta wait for the findings.

[IllegalArgument]

Actually, they do.

Aaron

Then it will be interesting to see what the investigation says.

[Rob Lister]

Actually, they do.

Aaron

I know the military versions of the 737 have it but I didn't know the civilian versions did. Got a link?

[HeavyAaron]

I know the military versions of the 737 have it but I didn't know the civilian versions did. Got a link?

I stand corrected. I thought the TCAS used RADAR. And of course passenger planes are required to have a TCAS system. Instead it depends upon transponder interrogation.

Bad Aaron.

Appologies around.

Aaron

[chracatoa]

Aircraft collide in mid-air when they attempt to occupy the same space at the same time.
The suprising part of this is that that truth holds independantly of the year of manufactor of the respective aircraft.

Are you sure? I thought they had a law against it or something :)

No, I mean they both have collision detection mechanisms(*) and (**). What are the odds both of them are turned off?

*NTSB celebrates 30 years (...) some of NTSB achievements: (...) Required anti-collision systems, called Traffic Collision Avoidance Systems (TCAS), as standard equipment on passenger flying aircraft.link (http://vanfossen.wordpress.com/2005/08/).

** I can't believe! Anything we say here we have to back it up with facts! :)

[Cleon]

No, I mean they both have collision detection mechanisms(*) and (**). What are the odds both of them are turned off?

*NTSB celebrates 30 years (...) some of NTSB achievements: (...) Required anti-collision systems, called Traffic Collision Avoidance Systems (TCAS), as standard equipment on passenger flying aircraft.link (http://vanfossen.wordpress.com/2005/08/).

** I can't believe! Anything we say here we have to back it up with facts! :)

Are you sure about that? The planes are Brazillian; do the NTSB regs apply to all aircraft made in the US, or is TCAS only required for planes operated by US airlines? How much jurisdiction does the NTSB actually have in this matter?

[chracatoa]

Are you sure about that? The planes are Brazillian; do the NTSB regs apply to all aircraft made in the US, or is TCAS only required for planes operated by US airlines? How much jurisdiction does the NTSB actually have in this matter?

No jurisdiction, but we tend to follow very similar rules. Therefore, I am not sure if both aircrafts actually had those systems, but aviation experts are puzzled how those systems did not work, so I assume they were there.

Update: here (http://noticias.terra.com.br/popinfografico/0,,OI402768,00.html) is a picture of the smaller jet. You can see damage on two wings.

And here (http://noticias.terra.com.br/popinfografico/0,,OI402511,00.html) is a picture of the disaster site. Not much to see here, it is a forest area.

ETA: The Embraer legacy jet was sold to a company in the U.S. and it was flying its mayden voyage.

[Luciana]

Apparently a "big piece" of the airliner dropped from the sky and hit his plane, forcing a landing as soon as possible. That would explain why the radar systems of both planes did not warn of their proximity.

Passengers testified that they didn't see anything, but they wouldn't if both planes met at 800km/h each.

[chracatoa]

Apparently a "big piece" of the airliner dropped from the sky and hit his plane, forcing a landing as soon as possible. That would explain why the radar systems of both planes did not warn of their proximity.

I did not know that, but if it's true it makes more sense. The pieces of the airplane are spread over an area about 1 km^2.

The question now would be why a brand new boeing 737-800 apparently exploded in mid-air. According to the National Agency of Civil Aviation the investigation will take 90 days.

[a_unique_person]

Apparently a "big piece" of the airliner dropped from the sky and hit his plane, forcing a landing as soon as possible. That would explain why the radar systems of both planes did not warn of their proximity.

Passengers testified that they didn't see anything, but they wouldn't if both planes met at 800km/h each.

I was wondering why the tailplane, which sits high on the small plane, and it's wingtip, both had damage. It was hard to see how that could happen. But the wingtip is pointing up.

[chracatoa]

From the New York Times:

(...) News reports were rife with conflicting speculation about the cause of the crash. Both planes were new and equipped with sophisticated radar designed to prevent midair crashes. Gol, Brazil’s second-biggest carrier, began flying the Boeing only a few weeks ago.

The business jet was on its inaugural flight as executives from ExcelAire Service Inc., a charter and aircraft management company based in Ronkonkoma, N.Y., took delivery from Embraer, the Brazilian aircraft manufacturer. Joe Sharkey, a reporter and travel columnist for The New York Times, was aboard, along with two ExcelAire pilots, two other company employees and two Embraer executives.

The Brazilian news media, citing unidentified sources in the Brazilian Air Force, said the smaller aircraft might have flown off course, clipping its wing against the jetliner. Others suggested that the Boeing might have had trouble and that a piece of its debris fell on the smaller plane.

Both aircraft were reported to have been flying at about 37,000 feet. The Gol, Flight 1907, left the Amazonian city of Manaus at 3:35 p.m. en route to Brasília, Brazil’s capital, and disappeared from radar little more than an hour later.(...)

[Crossbow]

Well, I am hardly an expert, but I do have some flying training and experience.

Anyway, sometimes the most dangerous time for an airplane is when it is brand new and/or when it has just completed a major maintenance cycle. Sometimes the mechanics do make mistakes and the pilots make mistakes as well since they may not be all that familiar with the aircraft.

[crackers]

Apparently a "big piece" of the airliner dropped from the sky and hit his plane, forcing a landing as soon as possible. That would explain why the radar systems of both planes did not warn of their proximity.

Passengers testified that they didn't see anything, but they wouldn't if both planes met at 800km/h each.

That would explain the part that puzzled me when I read about this accident - namely, how can it be that when a small plane and a big plane collide, the small plane lands safely and the big plane crashes?

[Darth Rotor]

Any airplane expert here? How can two modern airplanes like those collide in mid-air?
Easy, as Heavy Aaron said: try to occupy the same space.

A couple of points: commercial airliners have fairly restricted field of view from the cockpit. You can't see under the nose, nor much behind your lateral limit, nor directly above you. In the rear 180 degree of your field of view, you are blind. If one plane is descending at a higher forward speed than a plane slightly in front of and below it, both flight crews are blind to the impending collision.

TCAS cannot prevent a collision, it merely warns you of proximity of other aircraft. If you don't pick the aircraft up visually, you may still hit it. The rule is "see and avoid." It is possible that someone had an incorrect altimeter setting, though the chance is slim.

TCAS being tied to transponder and IFF interrogations (Mode III/C) is not a fool proof system. Basically, if there was any lapse in coverage, a TCAS unit was not working, not on, or a transponder was not on, or an altimeter error was entered (which would influence the atltitude the aircraft was reporting to the system) there is room for both flight crews to believe they were not at co-altitude.

The final rule is See and Avoid. Apparently, someone didn't. There is no mention of the weather conditions at flight level 370. A thin cirrus layer can be a vision obstructor. Avoiding thunderstorms could have been a factor.

At those altitudes, an aircraft is assigned an altitude that is cleared of other aircraft. (Controller altitude assignment/ATC might be a factor.)

What is the difference between a controller and a pilot?

If the controller screws up, pilots die.

If the pilots screw up, pilots die.

Of course, if both screw up, the pilots (and passengers) die.

None of this rules out 4' rebar with 3" centers, controlled demolition, suitcase bombs, a plot involving Larry Silverstein, or a failure in de-icing equipment. Nor does it rule out explosive decompression, which would have the crew dead pretty quickly.
The 737 was flying since Sept. 12 and it had 200 hours of flying. The legacy jet was making its inaugural flight to the U.S. (nobody was injured, it landed safely).
Age of aircraft is not as important as how they are handled and maintained.
On a side note, a conspiracy theory is already brewing. Today is elections day here and some people are saying someone caused the crash to influence the elections (though I have no idea how it would change anything).
The same way the train bombs in Spain influenced that election? *shrugs*

DR

[KingMerv00]

Any airplane expert here? How can two modern airplanes like those collide in mid-air?

An odd question.

The Federation has not perfected the phasing cloaking device yet.

[Crossbow]

That would explain the part that puzzled me when I read about this accident - namely, how can it be that when a small plane and a big plane collide, the small plane lands safely and the big plane crashes?

It does not always work that way.

[HeavyAaron]

Well, I am hardly an expert, but I do have some flying training and experience.

Anyway, sometimes the most dangerous time for an airplane is when it is brand new and/or when it has just completed a major maintenance cycle. Sometimes the mechanics do make mistakes and the pilots make mistakes as well since they may not be all that familiar with the aircraft.

I thought of bringing this up, actually.

I don't have the luxery of flying brand new jets around... but...

I know with my insurance policy for my model planes, I have special rules about madien flights as they are inhariently more dangerous. A proven plane is more trustworthy than a new one. I have no reason to believe that's true of models but not the full scale variety.

Aaron

[HeavyAaron]

An odd question.

The Federation has not perfected the phasing cloaking device yet.

That development was in clear violation of the Treaty of Algeron 2311. I highly doubt the Romulans are going to sit by while we deploy that technology on passenger planes even once the technology is perfected.

Aaron

[KingMerv00]

That development was in clear violation of the Treaty of Algeron 2311. I highly doubt the Romulans are going to sit by while we deploy that technology on passenger planes even once the technology is perfected.

Aaron

Why do you hate the United Federation of Planets? Romulan shill.

[Luke T.]

Any airplane expert here? How can two modern airplanes like those collide in mid-air?

As a sailor, something that used to puzzle me even more was how two ships on the ocean can collide. I mean, come on, at least airplanes are moving fast...

[HeavyAaron]

Why do you hate the United Federation of Planets? Romulan shill.

Fine, I'll point the Tal'Shair to Philly when they come a 'knocken.

Aaron

[Rob Lister]

As a sailor, something that used to puzzle me even more was how two ships on the ocean can collide. I mean, come on, at least airplanes are moving fast...

I was aboard the USS Midway when it collided with the Panamanian Tanker Cactus. Extensive damage requiring our porting in PI for a month of repair ( :) )

I know exactly how and why it happened: a combination of

1) A mission exercise
2) Darken ship
3) Emcom Alpha
4) Two forklifts
5) Clever lighting of 4)

I'll leave it to the more militarily apt (Hutch and Luke types) to put 1 through 5 together.

[This Guy]

As a sailor, something that used to puzzle me even more was how two ships on the ocean can collide. I mean, come on, at least airplanes are moving fast...

That was one of the things I liked about Submarines. A lot less traffic around 150 feet under, than on the surface :)

[chracatoa]

Update: (http://www.nytimes.com/aponline/world/AP-Brazil-Plane-Crash.html) (NYT needs login)
Preliminary investigations indicate that the pilots may have turned off the transponder, that they knew the risks they were running and nevertheless they took certain attitudes that endangered the lives of people

Also (http://www.nytimes.com/reuters/world/international-crash-brazil.html?_r=1&oref=slogin):
The planes were both flying at 37,000 feet when the smaller plane and the bigger plane apparently scraped, the airline and an air force commander have said.(...) "Flights from here (Brasilia) to Manaus should be at even-numbered altitudes, like 36 or 38 thousand feet," Defense Minister Waldir Pires said in a telephone interview."And those from Manaus fly at odd-numbered altitudes."

[a_unique_person]

Why would they turn off the transponder, and fly at the wrong altitude?

http://customwire.ap.org/dynamic/stories/B/BRAZIL_PLANE_CRASH?SITE=CASDT&SECTION=HOME&TEMPLATE=DEFAULT&CTIME=2006-10-03-02-23-26

They were experienced pilots.

[Correa Neto]

The information so far avaliable is that untill Brasilia the Legacy should fly at 37K feet, going down to 36K feet from Brasilia to Manaus (where it should land).

There are some speculations that the Legacy pilots decided to test the jet over what they considered to be empty air space over a vast sea of broccoli. The pilots would have turned off the transponder and radio to avoid contact with the ACTs. Now, if this would be expected from experience pilots, I hope the answer is a no.

[chracatoa]

Why would they turn off the transponder, and fly at the wrong altitude?

The pilots deny any wrongdoing. They say they were following instructions from the air traffic controllers. They also say that the airplane transponder could be malfunctioning. Anyway, the black box should explain a few things.

Truth is, if the problem is with the Embraer jet or with the 737 the respective company may lose a lot of money.

[Darth Rotor]

As a sailor, something that used to puzzle me even more was how two ships on the ocean can collide. I mean, come on, at least airplanes are moving fast...
Typically, the answer is that the bridge watch team miscalculates the relative motion and rate of closure between two ships. As the picture crystalizes, they are then limited by the reponse time, turning rate, and lack of brakes on ships at sea in effecting an evasive maneuver, or a reversal of course, to avoide collision. You have to be thinking way ahead of a ship to maneuver it, in terms of minutes for big ones, taking advance and transfer (http://www.google.com/search?hl=en&lr=&safe=active&q=advance+and+transfer+shiphandling&btnG=Search)into account.

I have manned the helm, and had the con, on LSD's, FF's, DD's, CG's, and once JOOW(UI) on a carrier. (USS America CV-66) The big ships respond slowly, they are not like driving a speedboat. I also have had the con during underway replenishment evolutions on DD's, FF's, and CG's.

CBDR: avoid it.

See also Rob Lister's previously mentioned

) A mission exercise
2) Darken ship
3) Emcom Alpha
4) Two forklifts
5) Clever lighting of 4)

as contributing factors to misjudging closure between vessels.

DR

[Darth Rotor]

The pilots deny any wrongdoing. They say they were following instructions from the air traffic controllers. They also say that the airplane transponder could be malfunctioning. Anyway, the black box should explain a few things.

Truth is, if the problem is with the Embraer jet or with the 737 the respective company may lose a lot of money.
Turn off the transponder, and the ATC guys have a hard time getting evidence on their radar scope that you are off route, or at the wrong altitude. It's a more common occurrence than one might expect.

DR

[Dave1001]

Apparently a "big piece" of the airliner dropped from the sky and hit his plane, forcing a landing as soon as possible. That would explain why the radar systems of both planes did not warn of their proximity.

Passengers testified that they didn't see anything, but they wouldn't if both planes met at 800km/h each.

That seems extraordinarily improbable. But then again, any version of this story seems extraordinarily improbable. I'm most surprised that the smaller plan was actually able to land, apparently only sustaining minor injuries. I expect sales of that particular private jet model to skyrocket.

[chracatoa]

I expect sales of that particular private jet model to skyrocket.

- if the transponder was not malfunctioning, which seems likely. Regardless of the airplane, all we can say is that they were incredibly unbelievable lucky.

However, it does appear that they turned off the transponder. They had a new airplane, they were in the middle of nowhere, what could go wrong? It turns out they were in a relatively busy airspace corridor.

I don't know much of airplanes, but for some reason I thought that they had sophisticated radars such as those we see in movies - where they can see even missiles as "blips" in their 2-D submarine-like radars. I guess the real world is definitely not like Hollywood...

[Hamradioguy]

That was one of the things I liked about Submarines. A lot less traffic around 150 feet under, than on the surface :)

True, although you gotta watch out for hitting something on the surface as you come up. And then there are those pesky undersea mountains....

[This Guy]

True, although you gotta watch out for hitting something on the surface as you come up. And then there are those pesky undersea mountains....

True.

That picture has quite a story behind it. Only one death I believe, but most the crew had injuries of some sort. They still managed to get Her to a port.