Cockpit audio indicates problems with de-icing in last month's deadly plane crash, investigators say

The pilots of a Brazilian passenger plane that crashed last month, killing all 62 people aboard, reported failure in the system to remove ice from the plane, according to a preliminary report made public Friday by Brazilian authorities.

Investigators were careful to avoid saying this was the cause of the accident, and stress there is more work to be done. Still, their report lent further credence to aviation experts' main hypothesis: that the lift loss had been caused by ice formation on the plane's wings and failure of its de-icing system. Weather reports from the day of the accident predicted ice formation in the region where the plane went down.

Audio from the cockpit’s voice recorder included comments from pilots indicating there ice was accumulating and there was a failure in the de-icing system, said Paulo Fróes, an investigator in the the air force’s center for the investigation and prevention of air accidents, told reporters in Brasilia.

“There are still many doubts. This accident shouldn’t have happened, not in the conditions in which the plane was flying and was being operated. It had protection equipment,” Carlos Henrique Baldin, head of the center's investigation division, told reporters.

Operated by the airline Voepass, the flight departed Aug. 9 from the city of Cascavel, in Parana state, bound for Sao Paulo’s Guarulhos international airport. It crashed into the backyard of a home in a gated community in the city of Vinhedo, about 80 kilometers (50 miles) northwest of the metropolis of Sao Paulo .

Footage of the ATR 72 twin-engine turboprop plunging while in a flat spin horrified people across Brazil.