VINHEDO, BRAZIL, Aug 11 — Brazilian authorities on Saturday finished recovering the bodies of the 62 people who died when their plane tumbled from the sky, as experts began examining the doomed aircraft’s black boxes to determine the cause of the disaster.

Videos showed the ATR 72-500 plane in a sickening downward spin Friday before it crashed into a residential area in the town of Vinhedo, some 80 kilometres (50 miles) northwest of Brazil’s financial capital Sao Paulo.

The plane operated by airline Voepass fell almost vertically, landed on its belly and exploded in flames, striking with such force that it was nearly "flattened,” said Sao Paulo fire lieutenant Olivia Perroni Cazo.

"A total of 62 bodies (34 male and 28 female) were recovered and taken to the morgue in Sao Paulo for identification and delivery to their families,” the regional government said Saturday evening.

Two have already been identified through fingerprints, with Vinhedo Mayor Dario Pacheco saying they were the pilot and co-pilot.

The twin-engine turboprop, built by aviation firm ATR, was flying from Cascavel in southern Parana state to Sao Paulo’s Guarulhos international airport.

Experts from Brazil’s Aeronautical Accidents Investigation and Prevention Center (Cenipa) have begun analysing two black boxes recovered from the wreckage, containing cabin conversations and in-flight data, said the center’s chief, Marcelo Moreno.

It plans to publish a preliminary report "within an estimated 30 days,” the Brazilian Air Force said.

According to the Flight Radar 24 website, the plane flew for about an hour at 17,000 feet (5,180 meters), until 1:21 pm (1621 GMT) when it began losing altitude at a catastrophic rate.

Radar contact was lost at 1:22 pm, the air force reported. It said the plane’s crew "at no time declared an emergency or were under adverse weather conditions.”

‘No technical problems’

ATR, a joint subsidiary of European giant Airbus and Italy’s Leonardo, said its experts will assist in the investigation.

The plane, in use since 2010, was in compliance with current standards, the National Civil Aviation Agency said, adding that the four crew members were all fully certified.

Voepass’s operations director, Marcel Moura, said the plane had undergone routine maintenance the night before the accident and that "no technical problems” were found.

But experts suggested icing of the plane’s wings may have been behind the accident.

Moura said the plane was a type that flies at an altitude "where there is a greater sensitivity to icing,” but that conditions Friday were "within acceptable parameters for a flight.”

National mourning

The fiery crash transformed the plane’s fuselage into a mass of twisted metal. Despite the devastation, there were no casualties on the ground.

President Luiz Inacio Lula da Silva has declared three days of national mourning for what was one of the worst aviation accidents in the country’s history.

"It was horrible, horrible... such a sad tragedy,” said a trembling Lourdes da Silva Astolfo, 67, whose home is only yards (meters) from the crash site.

She told AFP she had first felt a "rumbling, almost like a tremor,” when she suddenly saw the plane almost directly overhead. Seconds later came the stunning impact and the horrified screams from neighbours as a thick cloud of acrid smoke billowed outward.

The normally peaceful, wooded enclave where the plane came down saw a steady stream Saturday of police cars, ambulances and firetrucks.

Voepass said all the victims were travelling on Brazilian identity documents. One woman was a dual citizen with Portugal, and there was also a family of three Venezuelans.

It was the worst major air disaster in Brazil in 17 years.

In 2007, an Airbus A320 of Brazil’s TAM airlines overran a runway at Sao Paulo’s Congonhas airport and crashed into a warehouse, killing all 187 on board and 12 runway workers. — AFP