Authorities in Brazil are to examine whether a Manaus Aerotaxi Embraer EMB-110P1 Bandeirante was operating above weight limits when it crashed into a river in the Amazon, killing 24 occupants.

Twenty-eight passengers and crew were on board the twin turboprop, which was flying between Coari and Manaus when it came down in the Manacapuru river on 7 February, about 75km (40nm) from its destination.

According to reports citing survivors' accounts, the aircraft crashed after suffering an in-flight engine failure.

While the cause of the accident is still under investigation, the number of occupants exceeds significantly the number of seats on the aircraft (PT-SEA), which according to Flight's ACAS database was 27 years old.

A source at Manaus airport says the aircraft had 20 seats, although there is no confirmation that the airline was certificated to operate flights with more than 20 passengers. He also says that the passenger list only includes 20 names, whereas there were 26 on board, plus the two pilots.

But an employee from the airline denies that the aircraft was overweight, suggesting that several children travelling on adults' laps could account for the high passenger count.

A local Brazilian civil defence source says the police are already investigating documentation of the aircraft, to establish whether it was overloaded and could not manoeuvre adequately on a single engine.

"But the final cause will obviously be determined by [the Brazilian inquiry]," he says.

The Brazilian air force says there was a "sudden loss of radar contact and communications" with the aircraft. Images from the scene show the fuselage largely submerged, with just the empennage and rear exit clear of the water.

Manaus Aerotaxi says the crash occurred at 13:50. "Circumstances and the cause of the accident are being determined by the competent authorities," it says. "Manaus Aerotaxi is providing all assistance to the rescued passengers and relatives of the victims."

Source: Flight International