By: Shuwan Qin
On Friday, August 9th, a plane going from Cascavel, Brazil to Sao Paulo spin-plummeted to the ground of a small gated community, killing all 62 people on board. The plane was carrying 58 passengers, including a D.J. and a judo referee, and 4 crew members. According to The New York Times, Brazilian investigators on Saturday began analyzing the black boxes from a São Paulo-bound flight to try to understand why the passenger plane fell from 17,000 feet. Experts have studied what happened but could not come up with a definite reason. However, they have formed theories.
According to aviation experts, the plane stalled, which meant that its wings had lost the lift needed to keep the aircraft floating, causing it to stop flying and start falling. “You can’t get into a spin without stalling,” said John Cox, an airline pilot for 25 years who now aids plane crash investigations. “It’s A plus B equals C.” One of the most popular theories is that the plane stalled partly because of severe icing. Icing means that ice formed on a part of the plane, like the wings. Experts say that with severe icing, a plane would have to travel faster to avoid stalling. The way the aircraft fell, spinning out of control, is characteristic of someone who lost the functionality of the wing and the aircraft controls,” said Celso Faria de Souza, a Brazilian forensic expert in plane crashes. “This can happen because of ice.”
However, icing still doesn’t seem like a cause of the crash, or a least not a big cause. After all, passenger planes are equipped with de-icing systems, and this ATR 72-500 turboprop had rubber tires on the wings that inflate and deflate to break up ice. It is unknown if the crew did not activate the system or if it was activated or failed. Mr. Cox said that the plane’s speed dropped sharply minutes before the crash, but before that the speed of the plane was at about 325 miles per hour, which was not slow enough to cause a stall unless icing is extremely severe. That was also unlikely. “We’re talking about Brazil here, not Antarctica,” Mr. Cox said.
Under most circumstances, pilots can prevent icing from causing a stall, even if the plane’s systems fail. After all, pilots see the icing on the plane, and descend to a lower altitude for warmer air. They usually alert air traffic controllers before descending, before for some reason the pilots of this plane did not communicate with the controllers before the crash. There was just no warning at all. “They may have tried to speak and the radio failed, the communication failed,” said Joselito Paulo, president of the Brazilian Aviation Security Association. “Or they made the communication, but it wasn’t intercepted by air traffic control.” However, the failing of both the de-icing system and the communication system is unlikely.
Experts are further investigating what had happened to the plane and hope they will have results soon.