Black Box Points to Human Error in Brazil Air Disaster

Aug. 2, 2007
The data from the black box aboard the airliner that crashed July 17 at Sao Paulo's Congonhas Airport indicates pilot error was the cause of Brazil's worst aviation disaster.

The data from the black box aboard the airliner that crashed July 17 at Sao Paulo's Congonhas Airport indicates pilot error was the cause of Brazil's worst aviation disaster, Folha de Sao Paulo newspaper reported Wednesday.

In an exclusive based on leaks from unnamed sources, Folha said that information extracted from the TAM airliner shows the cockpit crew mishandled the controls of the Airbus A320 as they were trying to land the jet on a wet runway at Brazil's busiest airport.

The plane bounced off the tarmac and barely missed vehicles whizzing by on a crowded highway before crashing into a warehouse and gas station and bursting into flames.

All 187 people aboard the aircraft and 13 more on the ground were killed.

Information published by Folha reinforces other reports by the weekly Veja and on Wednesday sparked a broad debate in Congress, where a commission included the accident among the investigations it is carrying out into the chaos confronting Brazil's air transport industry.

The commission was said to have received on Tuesday the information from the black box and was intending to discuss that material on Wednesday in closed session, but the release of part of the data by the press provoked a series of accusations over the source of the leak and about whether it was still worth it to keep the material under seal.

According to the version offered by Folha de Sao Paulo, which has not been confirmed or denied by the authorities, one of the flight control levers that regulates the engine power was in the incorrect position when the pilots tried to land the plane at Congonhas.

That error, the paper added, meant that while one engine was trying to brake the aircraft, the other was still accelerating it.

The confusion of the pilots, the daily added, was due to the fact that when the plane has one of the reverses (i.e. the auxiliary braking system) engaged the engine power levers must be in a different position from that used during normal procedures.

The daily reported that investigators are not ruling out a possible failure in the plane's computer system, which could have interpreted the pilots' commands as an order to try and take off again without attempting to brake.

Folha also included in its report some of the dialogue between the pilots in the cabin, which the congressional commission insisted on keeping under seal because they reveal a scene of growing terror in the final moments of the flight.

According to the daily, at the moment of landing one of the pilots confirmed that one of the reverses was not functioning and immediately added that the plane's spoilers also were not working.

"Decelerate, decelerate, decelerate," said one of the pilots, according to the Folha version, upon noticing that none of the braking systems was working.

"We can't, we can't, we can't," the other responded.

Brazil's aeronautical authority announced last Saturday in a communique regarding the report of possible human error and warned that it was premature to draw any conclusion.

"The hypotheses presented in the information are some of several others that are being investigated with the same depth," the agency said in a response to a story in Veja.

Late Tuesday, the congressional panel probing Brazil's troubled civil aviation sector said that days before the July 17 crash, a dozen pilots warned the control tower at Congonhas that the airport's main runway was slippery.

The congressional commission decided to publish the document of the Brazilian air force - which is responsible for air traffic control - containing control tower reports from July 15-17.

The reports presented by the controllers described the runway as "very slippery" and on which it was "very difficult to brake the airplane," among other observations.

One day before the tragedy, a plane owned by the regional carrier Pantanal Airlines with 21 people on board skidded upon landing at Congonhas, albeit without further incident.

The state of Congonhas is investigating the cause of the accident.

The runway is too short for large aircraft, lacks a security area and at the beginning of this year had been temporarily closed by a court order because of the inadequate conditions prevailing there.

When the situation was corrected between May and June, the runway was reopened without a system of grooves in the pavement that normally help to drain rainwater off it and help planes slow down properly upon landing.

Brig. Gen. Jose Carlos Pereira, who is in charge of the government-owned firm that administers Brazil's airports, downplayed the comments of the pilots.

"That same day, 500 other pilots landed on the same runway and landed with the same rain, the same wind, saying that the runway was very good," Pereira said.

Meanwhile, President Luiz Inacio Lula da Silva's Workers Party, or PT, said Tuesday that "big media" and "the rightist opposition" were trying to use the plane crash to discredit the government.

Lula, now in his second four-year term, has been criticized for not coming to the accident site personally to comfort the relatives of the victims.

He broke his silence three days after the accident in an official speech in which he announced changes to the Sao Paulo air traffic system to decongest Congonhas. Shortly thereafter, Defense Minister Waldir Pires - the man ultimately responsible for the country's air industry sector - resigned.