Brazil 737-800 mid-air today, 155 on board. (merged threads)

[JEP]

Originally Posted by Van_Hoolio

Here's an article that accuses the American pilots of the Legacy of operating with the transponder off:

What If......

o.k. say the Legacy turned off its transponder would the 737 have still been able to see it? Or does the TCAS-type equipment need to see the transponder? Does the radar sweep pick up the a/c or the code of the a/c?

[jtrain609]

TCAS doesn't look for other aircraft, it looks for other transponders. Even if the Mode C was off, but the thing was still turned on the 737's TCAS would have seen the other transponder approaching.

[Bandit_Driver]

Originally Posted by JEP

What If......

o.k. say the Legacy turned off its transponder would the 737 have still been able to see it? Or does the TCAS-type equipment need to see the transponder? Does the radar sweep pick up the a/c or the code of the a/c?

ATC Radar is really two systems. One being the radar and the other being the interrogator. The radar "paints" the aicraft and provides its general position. The interrogator talks to the aircrafts transponder and retreives the assigned code and altitude (if it is a mode C transponder). The ATC computers then attach that info the primary target on the controls screen. The computers also figure out the aircrafts Ground Speed. With the transponder ON ATC can usually see you well before the primary radar can get a return.

TCAS is absolutely blind to an aircraft without a transponder or one that is turned off. TCAS will see a transponders that are squawking a code and provide show their relative positions. It was also provide a TA with those aircraft. If the transponder of the offending aircraft is also providing altitude TCAS can provide a TA the an RA.

As others have said, something is strange about this accident. I hope that the Brazillian government doesn't try to scape goat the corporate pilots.

For those interested is a link to more TCAS info: http://www.arinc.com/downloads/tcas/tcas.pdf

[777forever]

Originally Posted by Ophir

Have you seen this!

.


http://www.nytimes.com/2006/10/03/bu...th&oref=slogin I think you may need to register for that link. But it should be free.

How in the world do you guys think the 737 hit the Embraer just so it took off a piece of the winglet and nipped the elevator? Thats a very small amount of damage if you been hit by a plane traveling 600 miles an hour in the other direction. Seems to me the Gol hit the embrarer with its wings during a steep bank. Anybody else have any ideas?

[Bandit_Driver]

Originally Posted by 777forever

How in the world do you guys think the 737 hit the Embraer just so it took off a piece of the winglet and nipped the elevator? Thats a very small amount of damage if you been hit by a plane traveling 600 miles an hour in the other direction. Seems to me the Gol hit the embrarer with its wings during a steep bank. Anybody else have any ideas?

That is consistant with what has been published. The 737 allegedly banked at the last minute to avoid the Challenger. I am still curious as to why the 737 crashed?

[SeanD]

Originally Posted by Bandit_Driver

That is consistant with what has been published. The 737 allegedly banked at the last minute to avoid the Challenger. I am still curious as to why the 737 crashed?

I wondered the same thing after seeing that pic of the Legacy. Perhaps fuel leaking from the wings of the 737 after impact causing an explosion? It will be interesting to see what develops.

[mpenguin1]

Prosecutors could charge two American pilots of an executive jet with manslaughter following the high-altitude collision with a Brazilian jetliner that apparently led to a crash that killed all 155 people aboard, federal police said Wednesday.

Police seized the passports of pilots Joseph Lepore and Jan Paladino, both from New York State. The two were not arrested, but cannot leave the country.

"We will start investigating if the two pilots caused the accident and if they are considered guilty, they could be charged with involuntary manslaughter," Pereira said.

http://www.airportbusiness.com/artic...tion=1&id=8335

[Mahesh]

A little while ago, I ran into my friend in the hallway at my work. He told me that one of the pilots on the Legacy was his FO at ACA.

My friend has been talking to him daily and helping get more information on what happened. Apparently an AD is supposed to come out soon for that model of the transponder for suddnly shutting off!

We have a lot of TCAS experts here (they prototyped the initial TCAS systems) who are looking into it also.

Also, the same Legacy pilot was furloughed from AA so their union is also helping out.

[surreal1221]

Originally Posted by Mahesh

Also, the same Legacy pilot was furloughed from AA so their union is also helping out.

Very good!