THE TRANSPONDER

...You'll be hearing a lot about the transponder on the Legacy 600 as the Brazilian authorities continue scrambling to find any way possible to shift blame to the American pilots and keep it away from the sorry mess that is Brazil's air traffic control system -- and the Brazilian air force, which runs that system and jealously guards its honey-pot of a budget.

It's now generally accepted that the Legacy's transponder was not working properly as the business jet passed through the air sector of Brasilia and into the radar and radio blind zone where the responsibility for the plane shifted to the ATC center near Manaus. It is also not in any serious dispute that Brazilian air traffic control explicitly assigned the Legacy to an altitude of 37,000 feet, on a collision course with a Gol 737 coming in the opposite direction.

The federal police accusation against the pilots, cobbled together in a last-minute attempt to keep them from leaving the country Dec. 8, deftly ignores the weight of evidence that air-traffic control caused this disaster, and instead accuses the pilots, in effect, of failing to notice that their transponder wasn't working, thus causing a threat to Brazilian air traffic security.

In their reckless lunge to criminalize the accident and scapegoat the pilots, the Brazilian authorities have conspicuously failed to address what is now also no longer in dispute: grossly unsafe conditions in Brazil's air traffic control system, aggravated by a demoralized work force, some of whom are inadequately trained, and a large number of whom are not proficient in English, the mandatory language of aviation the world over.

Instead, the Brazilians are seeking to build a case against the pilots based on a transponder, an electronic device in the cockpit that provides a backup signal for air traffic control and triggers an anti-collision alarm to any approaching aircraft. Once air traffic control had the two aircraft on a collision course, bearing down on each other at a closing speed in excess of 1,000 miles an hour, and once the two planes disappeared into a radar blind zone that Brazilian authorities until recently loudly insisted did not exist, the transponder and the anti-collision warning system it is designed to trigger would have been the last possible slim chance the two aircraft had of avoiding impact.

Aircraft avionics are hugely complicated, and there is no way a pilot can be expected to be aware of every electronic device on a plane. "A transponder is not on the scan list" of things a pilot is routinely expected to monitor, one veteran pilot told me.

There is no signal to tell a pilot that a transponder has failed or switched into the standby mode. However, it is fully expected that ATC -- where controllers should know instantly if a transponder has failed in a plane they are monitoring -- immediately notifies an aircraft that its transponder isn't transmitting.

According to Brazilian authorities (not to mention actual reliable sources), the Legacy transponder was not transmitting for 50 minutes before the collision. There was no communication from air traffic control to that effect.

The model of transponder used in the Legacy 600 does, incidentally, have some recent history. On Sept. 12, the Federal Aviation Administration published a so-called "Airworthiness Directive" addressing certain transponders made by Honeywell which, the FAA directive said, are prone to "erroneously going into the standby mode." Among the aircraft equipped with the transponders in question are certain models in the Embraer 135 and 143 lines. Legacy 600 are business jets based on those commercial jet models. Both Embraer and Honeywell have said that the transponder on the Legacy 600 involved in the Sept. 29 accident was not one of those involved in the directive.

Nevertheless, the issue of a possibly faulty transponder was not considered urgent. Embraer requested and received from the FAA a 14-day extension of the time required to bring affected transponders into compliance. "Embraer asserts that the loss of the transponder does not pose so great of a hazard to justify such an urgent compliance time," said the FAA, which had originally asked for compliance by 15 days after the effective date of the directory, Oct. 17.

"We have determined that extending the compliance time to 14 days will not adversely affect safety," the FAA directive said.

On such thin straw the Brazilians are building a criminal case against the two Americans while they continue covering up the real cause of the disaster. As I have said here often, the fix is in.

Meanwhile, in an indication of just how harebrained the Brazilian authorities are, and how much this issue is being shaped to appeal to public sentiment in Brazil, the police official in charge of the criminal investigation, Ramon da Silva Almeida, actually felt the need to denounce the American pilots for their appearance on the "Today" show Friday morning, during which they told interviewer Matt Lauer that they did nothing wrong.

"They are doing what one would expect, defending themselves," the police chief sarcastically informed O Globo of the pilots' statements on American television.

Wonderful Waldir Pires also remains in the act. "The Minister of Defense Waldir Pires denied that the government detained the two pilots," O Globo reported yesterday without a hint of irony.

Uh, oh! Back down the rabbit hole we tumble! Not detained? Hey, where were these guys for 70 days?

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