Death came without warning for the 216 passengers aboard the Air France Airbus that crashed into the Atlantic off Brazil last June, according to the investigators’ account published yesterday.

The latest report on Flight 447, a landmark disaster for aviation, said that no cause could yet be attributed but it confirmed that faulty speed sensors were partly to blame and once again implied possible errors by the crew.

Study of debris and 51 salvaged bodies showed that passengers had not been told of an emergency as Flight 447, with 228 aboard, hurtled towards the ocean while the pilots fought to regain control.

The cabin crew were not in their seats, no oxygen masks had deployed and life jackets were still in their wrappers. The aircraft did not lose cabin pressure, as previously thought, and it was not configured for ditching when it smashed belly-down into the water, said the report from the BEA (Bureau of Investigation and Analysis). This made clear that the crew had not prepared passengers for an emergency, pilots said.

Adding new detail to previous findings, the investigators said that 43 of the 51 bodies, which were from all parts of the cabin, showed severe fractures to spinal columns, pelvises and chests. These injuries reflected the upward shock to seated passengers of an aircraft hitting the water belly first, it said.

The investigators touched on an assumption that the two co-pilots may have been flying the aircraft rather than the veteran captain. “The captain may have been taking a rest or may have been at the controls, something that the investigation has not yet been able to determine,” they said. Long-haul captains usually rest for a period during the night-time cruise. The captain’s body was the only one of the three to have been recovered, which suggested that he was not on the flight deck, experts said.

The BEA, which is under fire from victims’ families for the slow pace of its work, said that no cause could be assigned without the “black box” flight recorders. A new deep-sea search is to start in the new year in the area where the regular Rio-Paris flight fell out of the sky.

The report partly blamed the speed sensors, known as Pitot tubes. Automatic data messages from the stricken aircraft showed within hours of the June 1 crash that the airliner had lost Pitot data while flying in a storm. This in turn led to a loss of automated flight controls. “It was an inconsistency in the measurements that initiated the disconnection of the various control systems: autopilot, autothrust and flight director,” the BEA said.

The consensus among Air France pilots and aviation experts is that the technology failure led to the airliner entering a high-altitude aerodynamic stall from which the crew were unable to recover.

The BEA recommended international measures to raise standards for speed data systems at high altitude. Also, not enough is known about the weather at high cruising levels, it said. It also called for better flight data recorders and new links to report parameters in “real time” by satellite.

The investigators angered the unions by implying again that the pilots of the A330 Airbus may have failed to follow standard procedures for retaining control of an aircraft with a faulty flight system. The agency studied 32 incidents of pitot failure since 2003 and noted that the crew in each of them had kept control by following Airbus methods. It also said that the three pilots on AF 447 had just completed refresher training in handling speed anomalies and that there had been no failure in the attitude instruments — modern artificial horizons — which are vital to piloting airliners.

Air France’s main union said that the BEA was seeking to help Airbus and the airline by shifting blame to dead pilots rather than questioning the systems of the highly automated airliner. “The only established fact in this investigation is the false speed data,” said Eric Derivry, an Air France captain and official with the National Airline Pilots’ Union (SNPL). “We are not saying that pilots never make mistakes, but the BEA is pointing the finger to create the impression that the pilots were not up to handling the plane,” he told The Times.

Gerard Arnoux, head of the Union of Air France Pilots (SPAF), told The Times that the pilots do not understand why the investigators are reluctant to conclude that the aircraft was in a deep aerodynamic stall "which it was obviously in". The Bureau was trying to implicate the pilots without any evidence, he said. "There is nothing to justify saying that our colleagues did not behave correctly." It suits everyone to point the finger at them.

He also questioned why the investigators had not highlighted the lack of reliable weather information on the flight decks of modern airliners. With satellite pictures that are freely available, the crew would never have become entangled in severe weather, he said.