Family members of Gol's flight 1907 victims believe that the transponder of the Legacy jet was voluntarily disconnected by US pilots, Joseph Lepore and Jan Paladino, causing the accident of September 29, 2006 in Brazil with a death toll of 154 people.
"We already knew that they could not have disconnected the transponder inadvertently with their feet, their laptop or any other way; however, the civil aviation authority's statement, that there is no indication of intentional disconnection, is unacceptable as they were cognizant of their entire dialogue during the trip," says Angelita De Marchi, president of the Association of Relatives and Friends of Gol's Flight 1907 Victims.
De Marchi says a transcript of Gol's flight 1907 black box conversations support the families' beliefs.
Rosane Gujthar, Rolf Gujthar's widow, agrees that the civil aviation authority cannot exclude the possibility of intentional disconnection of the transponder given the pilots' own remarks, recorded in the black box, which she says illustrates their lack of good judgment, negligence and lack of expertise with the equipment.
FMS (Flight Management System) is responsible for the management of several of the plane's functions, like flight planner, navigation, performance calculation, fuel consumption, etc. "It cannot be said that they did not disconnect the transponder intentionally, since they assumed the risk of piloting an unfamiliar airplane, even its FMS," states Gujthar.
"So, with all this, we want to know which other devices from the Legacy were turned off, besides the transponder and the TCAS, which we know of from the investigations. After all this, how can the civil aviation authorities claim that there is no indication of intentional disconnection? Their decision to pilot an unfamiliar aircraft, not knowing their equipment and international manuals, is an indication that they knew they could endanger the lives of the crew and other people."
After the accident, at 19h56min54s UTC (Coordinated Universal Time), a conversation between the crew took place, while they tried to establish contact with Brasília's control tower. The American pilots began to look for the closest airport, and the pilot, Joseph Lepore, assumes he has the TCAS (Traffic Collision Avoidance System) turned off.
"The most ironic thing is that minutes after the collision at 19h57min50s, the Legacy's transponder reappeared in the secondary radar of the Amazon ACC, fully identified, with speed, altitude and aircraft information," says Rosane.
Captain George William Araripe Sucupira, president of the Pilots and Airplane Owners Association (APPA), states that "it would be practically impossible" to have an involuntary disconnection of the transponder/TCAS system.
"It is impossible to disconnect a transponder without the pilot's intervention. How can I turn off the transponder if I did not mess with the button? I can only turn it off if I change its position. Therefore, the transponder can only be deactivated voluntarily by the pilot, either by pressing or turning the button. The transponder of modern airplanes is coupled with a TCAS. The TCAS is a very basic instrument. That hypothesis does not exist. There is no way to turn off the transponder by accident."
Angelita De Marchi states that the families are stressed due to the lack of answers. "We are surprised every time with a new analysis or a new statement about the accident. We are tired of not getting straight answers about what happened the day of the accident and who is responsible. We cannot go on with our lives until this is over," she says.
The victims' families are awaiting the official report from the civil aviation authority, as well as the decision on the Positive Conflict Competence, which is under revision by Justice Paulo Gallotti of the Supreme Court.