06 JUN 2009 _______________________________________ *AF447 Data May Lead To Speed Discrepancies, Misleading Pilots *Airbus: Lost jet had inconsistent airspeed data *Memo: Air France replacing flight instruments *French nuclear submarine to assist A330 search *NTSB investigates American Airlines close-call *UTAir crew tried to cover up serious Tu-154 airprox **************************************** AF447 Data May Lead To Speed Discrepancies, Misleading Pilots Data from Air France flight 447's automatic ACARS message indicate the pilots may not have had access to the correct speed information during the final minutes of the flight. The list of fault messages sent to Air France's operations headquarters in Paris includes a sequence of notes that hints at the three Air Data Inertial Reference Unit (ADIRU) computers to show diverging information. ADIRU compiles data delivered by the pitot tubes and processes it to the aircraft's other computers. The list, obtained by The DAILY, among others, gives an insight into the sequence of computer and system failures on the Airbus A330-200. During the last four minutes the situation worsened. At 2:10 a.m. zulu, the autopilot was either switched off by the pilots or automatically. The function is switched off automatically if speed drops by some margin below a previously defined minimum. The aircraft subsequently flew in "alternate law" conditions that do not provide full automatic envelope protection. Other functions, such as the Traffic Alert and Collision Avoidance System (TCAS) or the rudder travel limiter failed at the same time. Shortly after the ADIRU notices (2:11 and 2:12 a.m.), the ACARS alerts show a "F/CTL PRIM 1 FAULT" and a "F/CTL SEC 1 FAULT" indicating malfunctions of the first primary and secondary flight control computers. Shortly thereafter, the string of messages ends. In an "Accident Information Telex" to operators, Airbus writes that the ACARS content indicates that "there was inconsistency between the different measured airspeeds. Therefore and without prejudging the final outcome of the investigation, the data available leads Airbus to remind operators what are the applicable operational recommendations in case of unreliable airspeed information." The diverging speed inputs could come from icing of the pitot tubes, industry sources indicate - a phenomenon not uncommon when flying in weather conditions that prevailed at the time of the accident. In its telex, Airbus points out that "the aircraft was crossing a tropical multicell convective area at the time of the accident." The ACARS content only shows what systems and computers malfunctioned, but there's no information yet available about what actually happened to important parameters, such as airspeed, altitude or pitch angle during the last few minutes of the flight. It also is still unclear if the loss of control happened as a result of a multiple system failure and subsequent stall or because of the severe turbulence that is likely to have hit the aircraft during its 75-mile (or 12 min.) travel through the storm front. Brazil's Defence Ministry had to admit on Friday that wreckage found floating on the Atlantic on Tuesday does not belong to the aircraft. A senior French government official pointed out that French search troops have not found a single piece of the aircraft yet. While there appears to be no hope for survivors among the 228 on board, finding the accident site quickly could turn out to be crucial to discover more about what caused AF448 to crash. The black box's batteries last for around 30 days, and the French air accident investigation branch BEA has said it is not optimistic it can find the piece in deep sea. Separately, a Spanish newspaper quotes the crew of an Iberia Airbus A340 that flew seven minutes behind AF447 on the same track. According to the crew, air traffic control failed to contact the Air France jet after 1:33 a.m. zulu in spite of trying several times. The Iberia pilots then tried to get in touch with their French colleagues, too, but did not succeed either. http://www.aviationweek.com *************** Airbus: Lost jet had inconsistent airspeed data RIO DE JANEIRO, Brazil (CNN) -- 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 (220 miles) 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 (9,840 feet) to 7,500 meters (24,600 feet). 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. ************** Memo: Air France replacing flight instruments PARIS (AP) - An Air France memo to its pilots Friday about the crash of Flight 447 said the airline is replacing instruments that help measure airspeed on all its medium- and long-haul Airbus jets. Investigators have focused on incorrect speed readings as one potential factor in the crash. With Brazil and France disagreeing about whether pieces of the jet have even been found in the Atlantic, investigators are using the last messages sent by the plane to determine the cause and try to avoid future disasters. Air France declined to comment on the memo obtained by The Associated Press, saying it was for pilots only. FIND MORE STORIES IN: Airbus | Air France Airbus said the matter was part of the investigation into the crash that killed 228 people flying from Rio de Janeiro to Paris Sunday. The Bureau of Investigation and Analysis, which is leading the French probe of the crash, said it would address all questions at a Saturday news conference. The memo sent Friday said Air France has been replacing instruments known as Pitot tubes and will finish in "coming weeks." It does not say when the replacement process started. The plane's "black boxes" may be miles below the surface and investigators are looking for clues in the messages sent from the plane's computers just before it disappeared. One theory: the outside probes that feed speed sensors may have iced over, giving incorrect information to the plane's computers. The autopilot may have then directed the plane to fly too fast or too slow when it met turbulence from towering thunderstorms. Airbus sent an advisory to airlines late Thursday reminding them how to handle the A330 in similar conditions. The memo sent by Air France Friday says that a series of actions to reduce the risks of loss of airspeed information are being reinforced by "notably, the improvement of pitot models on Airbus' fleet of medium- and long-haul flights." "On this topic, a program of replacing pitots with new models is underway," the memo reads. "It should be completed in coming weeks." Pitot tubes are L-shaped metal tubes - about eight inches long on their longer side - that protrude from the wing or fuselage of a plane. The pressure of the air entering the tube lets sensors measure the speed and angle of the flight, along with less vital information like outside air temperature. They are heated to prevent icing. A blocked or malfunctioning Pitot tube could cause an airspeed sensor to work incorrectly and cause the computer controlling the plane to accelerate or decelerate in a potentially dangerous fashion. Airbus said the French agency investigating the crash found that the doomed flight had faced turbulent weather and inconsistency in the speed readings by different instruments. That meant "the measured air speed of the aircraft was unclear," Justin Dubon said. In such circumstances, flight crews should maintain thrust and pitch and - if necessary - level off the plane and start troubleshooting, Dubon said. Meteorologists said the Air France jet entered an unusual storm with 100 mph updrafts that acted as a vacuum, sucking water up from the ocean. The moist air rushed up to the plane's high altitude, where it quickly froze in minus-40 degree temperatures. The updrafts also would have created dangerous turbulence. The jetliner's computer systems ultimately failed, and the plane likely broke apart in midair. Brazilian officials have insisted for three days that military pilots have spotted wreckage from Flight 447 scattered across the ocean's surface. Air Force Brig. Gen. Ramon Cardoso again expressed confidence Friday that at least some of the objects - an airplane seat, a slick of kerosene and other pieces - are from the plane that vanished Sunday with 228 people on board. "This is the material that we've seen that really was part of the plane," Cardoso said. But ships guided by planes in the search area have been hampered by extremely poor visibility, and have recovered no wreckage. "We don't have any information yet that any of the ships are near any of the objects," Cardoso said. The only piece retrieved so far, a cargo pallet, turned out to be sea garbage. Like other suspicious objects, it had to be hauled up and checked out, said Brazilian Navy Adm. Edson Lawrence. French officials stopped short of criticizing their Brazilian counterparts, but France's Transportation Minister Dominique Bussereau said his own country's searchers have found no signs of the Airbus A330. "French authorities have been saying for several days that we have to be extremely prudent," Bussereau told France's RTL radio. "Our planes and naval ships have seen nothing." A French Defense Ministry official, speaking only on condition of anonymity because he was not authorized to speak publicly on the matter, also questioned the Brazilian claims, saying French teams "cannot precisely confirm the zone where the plane went down." Cardoso also said a large oil slick spotted by search plane pilots was not from the Airbus, but that authorities believe another slick of kerosene was probably from the downed passenger jet. France is sending a submarine to the zone where the plane is thought to have gone down to detect signals from the two black boxes, said military spokesman Christophe Prazuck. The Emeraude, already in the Atlantic, will arrive next week, he said. The vessel, which can dive up to 980 feet is to be used to help try to detect the signals noises from the boxes - believed to be up to 13,100 feet underwater. It will try to capture the acoustic signals, which can last 30 days, Prazuck said. The Pentagon has said there are no signs terrorism was involved. Brazil's defense minister said the possibility was never considered. French Foreign Minister Bernard Kouchner agreed that there is no evidence supporting a "terrorism theory," but said "we cannot discard that for now." Brazil's Air Force was flying relatives of victims to the search command post in the northeastern city of Recife Friday to tour the operation and ask questions. Recife has a large air force base where debris and any human remains would be brought. *************** French nuclear submarine to assist A330 search France's defence ministry has deployed a nuclear submarine to aid the hunt for the Airbus A330 which disappeared over the South Atlantic on 1 June. The submarine, S604 Emeraude, is fitted with an array of radar and sonar equipment and will be brought into the search over the next week, says the French defence ministry. Two French naval vessels are also set to arrive in the next few days. French support for the search effort for the Air France A330 already includes a Boeing E-3, two Breguet Atlantique 2 aircraft, and a Dassault Falcon 50 maritime patrol jet. Source: Air Transport Intelligence news ************** NTSB investigates American Airlines close-call The US National Transportation Safety Board (NTSB) says it is investigating an operational error that resulted in two American Airlines jets coming within a half-mile of each other horizontally as they approached parallel runways at the Chicago O'Hare International Airport in visual weather conditions on the afternoon of 1 June. Due to an "air traffic control oversight", NTSB says Flight 879, an MD-82, while being vectored overshot the final approach course for runway 28 and continued northbound, "conflicting" with Flight 93, a Boeing 767 on final approach to runway 27L. "According to preliminary Federal Aviation Administration data, lateral separation decreased to 0.35 nautical mile (1.2km) and vertical separation was 0 feet before the conflict was resolved," says the NSTB, adding that there were no injuries or damages reported. Weather conditions were good at the time of the incident, with a cloud ceiling of 1,676m (5,500ft) and visibility of 8.7nm (10mi), says the NTSB. Source: Air Transport Intelligence news **************** UTAir crew tried to cover up serious Tu-154 airprox Russian investigators have disclosed that the UTAir Tupolev Tu-154M crew involved in a serious airprox with a Boeing 767-300 attempted to cover up the incident after landing at their destination. The federal air transport authority Rosaviatsia has completed its inquiry into the 24 April event, issuing 15 recommendations and advising that traffic collision-avoidance systems be fitted in all aircraft operating to busy airports. After departure from Moscow for Samara the Tu-154 crew failed to retract the undercarriage and the aircraft began descending, coming into conflict with a Transaero 767. Moscow air traffic controllers acted to separate the two jets. Rosaviatsia says the Tu-154's crew "tried to conceal" the facts after landing at Samara. Its inquiry has found that the crew, who were suspended, "allowed a number of violations" of flight operations requirements to occur, resulting in the aircraft's loss of separation with the 767. Among these failings was the lack of communication over the aircraft's change of altitude as it descended out of its assigned flight level. Source: Air Transport Intelligence news **************** Curt Lewis, P.E., CSP CURT LEWIS & ASSOCIATES, LLC