RIO DE JANEIRO , Brazil -LRB- CNN -RRB- -- Automated messages sent from Air France Flight 447 just before it crashed Monday indicate the plane 's systems were providing contradictory information about its airspeed , the jet 's manufacturer said on Friday . Friends and relatives of the 228 people aboard Air France Flight 447 attend a memorial service Thursday in Brazil . That suggests the pilots may have been flying too fast or too slow through the violent weather they encountered before the crash , officials said . In addition , investigators have said the plane 's autopilot disengaged , cabin pressure was lost and there was an electrical failure before the disaster . Airbus confirmed on Friday that in the wake of the crash it sent a Telex to operators of all Airbus models reminding them what to do when speed indicators give conflicting readings . The spokesman said the notice does not mean there is any major flaw in the aircraft , but is simply a reminder to pilots about what to do in the cockpit if they get conflicting information about air speed . Message transmissions from the aircraft in the final moments before it crashed Monday into the Atlantic Ocean show there was an `` indicated inconsistency in measured air speeds , '' Airbus said . The company did not elaborate . Experts said that could mean the pilot 's and co-pilots ' sensors were showing different speeds . `` If they 're malfunctioning , it can give a false read that can be misinterpreted in the cockpit , and a disaster can follow , '' said Peter Goeltz , the former managing director of the U.S. National Transportation Safety Board . While the pilots themselves sent no distress calls , the aircraft 's computer system relayed about four minutes of automated messages indicating a loss of cabin pressure and an electrical failure , according to investigators . Airbus said it sent the Telex Thursday night after the action was recommended by the French investigating agency , which plans to hold a news conference Saturday morning in Paris , France . Watch as experts question whether recovery is possible '' Meanwhile , the hunt for debris continued Friday , a day after a Brazilian air force official said debris plucked from the ocean was not from the Air France jet . A U.S Navy P-3 temporarily based in Brazil has flown three missions -- on Wednesday , Thursday and Friday -- in assisting the Brazilian government search for debris , but found nothing connected to the disaster , U.S. Southern Command spokesman Maj. Darryl Wright said . Earlier Friday , Goeltz said the search for Flight 447 's voice and data recorders is becoming more difficult as ocean currents disperse debris from the crash site . `` The clock 's ticking '' in the search for the plane 's recorders , he said . `` The batteries on these locator devices attached to the black boxes have a limited life span -- just 30 days , '' he said . `` The longer time goes on , the further away from the actual crash site the debris floats . '' All 228 passengers and crew aboard the Airbus 330 are presumed to have died when the plane disappeared northeast of the Fernando de Noronha Islands , an archipelago 355 kilometers -LRB- 220 miles -RRB- off the northeast coast of Brazil . The flight originated in Rio de Janeiro , Brazil , and was en route to Paris . Map of Flight 447 's flight path '' While the ocean depth in the area where the plane is thought to have crashed presents a challenge , the challenge may not be insurmountable , Goeltz said . `` We 've recovered boxes as deep as 6 - or 7,000 feet , '' he said . `` We 've recovered debris from as much as 10,000 feet . '' Authorities have said the depth of the water in the area ranges from 3,000 meters -LRB- 9,840 feet -RRB- to 7,500 meters -LRB- 24,600 feet -RRB- . Cmdr. Christophe Prazuck of the French Ministry of Defense said Friday that a French research vessel was expected to arrive this weekend in the search area carrying a deep-diving submersible . The submersible would try to pinpoint the recorders , but must rely on another vessel to retrieve them , he said . The submarine helped recover artifacts from the Titanic disaster . Meanwhile , France 's transportation minister warned that `` extreme prudence '' should be used in releasing information about why the plane crashed . It is possible the plane experienced a total electrical failure , officials have said . Goeltz said it is possible the jet 's speed indicator was faulty . `` That could really be disastrous and it 's happened before , '' he said , speaking generally . If it malfunctions , `` it can give a false read into the cockpit that can be misinterpreted , '' he said . Investigators also said the autopilot system may have failed . A Spanish pilot reported seeing an `` intense flash '' near where the plane is believed to have crashed , the Spanish carrier Air Comet said on Thursday . The co-pilot and a passenger on the flight from Lima , Peru , to Lisbon , Portugal , also said they saw a light . Air Comet said the pilot 's report has been sent to Air France , Airbus and the Spanish civil aviation authority . CNN 's Mike Mount contributed to this story .