The French aviation authority BEA said Monday it will make its third formal report from its investigation into how the plane crashed en route from Rio de Janeiro to Paris on June 1, 2009, killing all 228 people on board.

“This report will present the exact circumstances of the accident with an initial analysis and some new findings based on the data recovered from the flight recorders,” it said in a statement.

It added that it would brief the media in Paris at 2:30pm on Friday.

According to information from the recorders already released by the BEA, the pilots saw conflicting speeds on their instruments as the plane stalled and fell into the sea.

An interim inquiry had pointed to an icing problem with the probes measuring air speed but there has still been no definitive conclusion as to the cause of the crash.

The new elements in Friday’s report will “present the different chains of events that led to the accident” but will not formally establish the cause, a BEA spokeswoman told AFP.

“These first points of analysis will allow us to indicate the failures that led to the accident, but not their cause,” she said. A further final report is due later.

According to several experts, the deactivation of the autopilot could have been caused by the icing up of the air speed probes, known as Pitots.

Since the accident, Air France has replaced the Pitots on its Airbus fleet with a newer model.

Both companies are being investigated for alleged manslaughter in connection with the crash.

Pilot’s unions and some of the victims’ families have accused the airline of reacting too slowly to safety warnings but both Airbus and Air France insist they reacted properly.

“We are waiting for more information on the circumstances of the accident, how it took place and above all the technical state of the aircraft during the flight’s last moments,” said Robert Soulas of a victims’ families association.

“What has been released by the BEA has been very fragmented and has not allowed us to fully understand the situation,” he told AFP.

It took investigators nearly two years to salvage the black-box flight recorders from the wreck on the ocean floor in May.

Rescue workers recovered 50 bodies in the days immediately after the crash and this year retrieved a further 104, which were returned to France last month. More than 70 could not be recovered.