Jet Transponder Not Working Before Crash (I was right.....

[wakeme2008]

http://www.nytimes.com/aponline/world/AP-Brazil-Plane-Crash.html?_r=1&oref=slogin

October 20, 2006
Jet Transponder Not Working Before Crash
By THE ASSOCIATED PRESS

Filed at 1:02 a.m. ET

RIO DE JANEIRO, Brazil (AP) -- Early analysis of the flight data recorders from two planes that collided in Brazil's deadliest air disaster indicated the smaller jet's transponder was not signaling its location at the time of the accident, Brazil's defense minister said Thursday.

All 154 people aboard Gol Airlines flight 1907 were killed on Sept. 29 when the Boeing 737 crashed into Brazil's dense jungle after clipping an executive jet.

Defense Minister Waldir Pires told reporters that initial analysis by the International Organization of Civil Aviation in Canada showed the transponder aboard the Embraer Legacy 600 executive jet was not broadcasting the aircraft's location.
..cut..

The Legacy, on its maiden flight to U.S. purchaser ExcelAire Service Inc., landed safely at a Brazilian military base with none of the seven people aboard harmed.

..more at link....

I guessed when this happened that the New Jet's transponder was not working....

[Billy Burnett]

1. Article doesn't say transponder "not working". It says "not broadcasting".

Hmmmm.

Brazilian military handles ATC duties there.

:tinfoilhat:

[Xenotime]

6. not boradcasting = not working..

What is the point of it being there if it isn't doing what it is supposed to be doing. That's like saying, "DU is not working." And then the Admin saying, "No. It's working. Our Internet connection is down."

People don't care WHY something isn't doing it's job. They just know it is not working.

Besides, the title of the article is "Jet Transponder Not Working Before Crash"

[DemoTex]

2. Here is why that is so important: TCAS-II and RVSM

I doubt seriously that Brazil ATC (air traffic control) had radar coverage over the remote area of the jungle where the mid-air took place. That would make it like, say, the airspace over the North Atlantic Ocean.

RVSM is Reduced Vertical Separation Minima and TCAS is Traffic Alert and Collision Avoidance System. The former is possible because of the later. RVSM reduces altitude separation between aircraft (generally flying in opposite directions, or head-on) to 1000-ft (used to be 2000-ft at altitudes above FL 280 - 28,000'). RVSM was first used on the North Atlantic air navigation tracks a few years ago.

TCAS-II allows aircraft to "see" each other on a variety of displays and issues warnings and conflict resolution advisories ("CLIMB .. CLIMB NOW") if the "Tau" (time-based) envelope of protection is violated. TCAS-II is a function of the aircraft's Mode-S (data-link) transponder system. An aircraft without a Mode-S transponder (or with an inoperative Mode-S transponder) is invisible on the TCAS-II system and must not accept a clearance into a RVSM environment.

I flew the Beta version of the original Bendix TCAS-II system in the mid-1980s on a Boeing 737-200 and a North American Sabreliner 65. It worked beautifully then and they work much better now. TCAS-I and TCAS-II have prevented innumerable mid-air collisions. In fact, it is almost inconceivable that two aircraft equipped with TCAS-II could ever collide in flight.

As an ALPA-trained airline accident investigator, I would put TCAS in the top five of all-time aviation safety innovations. This mid-air over the jungles of Brazil should never have happened with TCAS. Now we are beginning to learn why.

For more info see Wikipedia:
http://en.wikipedia.org/wiki/Traffic_Collision_Avoidance_System


TCAS-II display on weather radar screen.

[karlrschneider]

5. Yo, Mac...do you think there is any chance it wasn't installed in

that plane?...I can't imagine that in an a/c of that class. Can it be turned off? I've been asked
a (very) few times to put the xpdr on standby and I don't recall any indication other than the absence
of the little 'reply' light to show it isn't transponding...
K

[DemoTex]

7. Like maybe a ferry flight to a completion center in the US?

Could be. But I would think the ferry kit would include a transponder, since a transponder is required for an ICAO IFR flight plan. If they were operating in a non-radar environment with RVSM, then TCAS-II should have been on board (anything less is suicide).

Mac

[karlrschneider]

8. I'm sure that's right but can you carry pax on a ferry flight?

I had to get one (ferry permit) for the Lodestar once when both generators blew up and I -think- it said crew only, but that was from RIC to TUL, nowhere near Brazil...
KS

edit to add ferry permit

[Hawkowl]

3. Brazillian Manufacturer to blame?

The article says that the Legacy was on its maiden flight to its new owners in the U.S. This means that the pilots had just picked the plane up from the Embraer manufacturer in Brazil. Often brand new planes have a few bugs in them that are worked out in the first 100 hours or so of operation.

[karlrschneider]

4. If the xpdr was actually malfunctioning (as opposed to, for example

being turned off, lost power, etc.) I would have to believe it failed sometime after departure
because surely ATC would have noticed it and informed the crew. There really isn't any way to
'test' them without some communication with a radar facility. In any case, Embraer did't manufacture
the avionics...they buy them from various manufacturers...Bendix, Collins, etc.

[jmowreader]

9. According to Embraer, you get TCAS 2000 and RVSM standard

http://www.embraerexecutivejets.com/english/content/aircraft/legacy600_equipment.asp

And although I've never built an airplane, it seems logical to me that they'd put all the avionics into the plane while it was sitting on the factory floor in Brazil and everything was easy to get to, than to put the whole plane together, fly it to the US and upfit it there. Besides, don't you need the instruments to fly that kind of a plane internationally?