Brazilian Air Traffic Controllers Put On High Alert

Many flight instructors will warn you to be very careful when setting your transponder. They will tell you to be especially mindful to avoid squawking "7" in the first digit because if you add another "7" or" 6" or "5", this sets off alarm bells, warning whistles, and panic horns for the controller-- signalling emergency, lost communications, and hijacking, respectively. 

A Brazilian pilot evidently didn't get the word because he inadvertently set his transponder to 7500 -- the international code for "hijacking in progress".

The Associated Press says the flight crew of the Brazilian airline Varig, Flight 2330, somehow set the transponder to the code and controllers gave them very special handling until the plane landed in the city of Salvador, about 900 miles northeast of Sao Paulo.

The pilot immediately told air controllers he really hadn't been hijacked, but the usual protocol is to assume the hijackers know the procedures. Therefore, once the signal is given, no amount of denial will keep them from taking it very seriously. The plane was isolated at the airport until authorities were convinced the plane really wasn't hijacked.

The controllers may also have been going by the book because of a furious controversy swirling around the fatal mid-air collision of a Brazilian jetliner and a business jet which may have been the fault of an inoperative transponder and flawed air traffic control direction. Controllers are engaged in a so-called "work-to-rule" campaign following all regulations to the letter, which slows down operations.

In the meantime, Brazilian authorities are looking into the non-hijacking incident and wondering how Brazilian aviation is in the international news for a second time regarding problems with a transponder.

FMI: www.dac.gov.br/