The Paris Air Show got underway this week with the fatal crash of Air France Flight 447 into the South Atlantic likely casting a shadow over the premier aviation event.
The Paris Air Show gives the aviation industry a venue to promote the latest innovations in aerospace technology and attract buyers for both commercial and military aircraft.
But Airbus will be under scrutiny following the June 1 disaster off the coast of Brazil that involved one of its Airbus A330 aircraft. Investigators remain in the dark about what caused Flight 447 to plunge into the Atlantic Ocean because the jetliner’s flight data and cockpit voice recorders have yet to be recovered. The only facts broadly agreed upon are that the airliner penetrated a region of severe weather, and the pilots were confronted with a rapid series of electrical system failures.
The mysterious loss of Air France Flight 447, which took 228 lives, will continue to trouble aviation safety investigators until the Airbus A330’s flight data and cockpit voice recorders are hopefully recovered from the depths of the Atlantic Ocean, providing concrete information on what caused the fatal accident.
But a week into the crash investigation and the search operation, speculation surrounds whether faulty airspeed indicators may have somehow played a critical role in the loss of the commercial transport.
The European Aviation Safety Agency (EASA), which certifies all Airbus aircraft, said the Airbus A330 is “airworthy” and “safe to operate” but added it was considering mandating expedited replacement of pitot tubes, the airspeed probes in question made by Thales.
Airbus A330s are fitted with three of these sensors on the front of the plane on either side. They calculate the speed according to the amount of air that passes through them.
But rainwater can also get into the sensors – a weakness that was quite well known according to experts, one of whom said a Qantas Airlines flight recently had problems of this nature with its air-speed sensors.
According to a written statement issued by EASA on June 9, “we confirm that the Airbus A330 type and all other Airbus aircraft types are airworthy and safe to operate.” But EASA added that “with regard to reports about a possible malfunctioning of the air speed indication system (pitot probes), the Agency is analyzing data with a view to issuing mandatory corrective action. As precautionary measure, the Agency is issuing a safety information bulletin, reminding operators of existing procedures to be applied in the event of loss of, or unreliable, speed indication.”
Based on health monitoring messages transmitted by the doomed A330 prior to the crash, it is theorized that pitot probes might have iced up, supplying inaccurate airspeed data to the flight deck. This, in turn, could have caused the pilots to fly too slow and stall, or too fast and rip the airframe apart.
Air carriers worldwide aren’t waiting for an emergency airworthiness directive from EASA. They are replacing the Thales-made pitot tubes. Delta, US Airways and United, which fly different models of Airbus jetliners, are among those affected.
The pitot tubes had not been changed on the Air France Airbus A330 conducting Flight 447. Others had been swapped out after Airbus recommended the Thales pitot tube replacement during regular maintenance. In November last year, Air France issued a warning note to its pilots about a “significant number of incidents” and “anomalies” with the functioning of the pitot tubes on A330 and A340 aircraft. The previous incidents on Air France Airbus craft started in May 2008.
Meanwhile, The Associated Press reports that several airline heads attending IATA’s 65th Annual General Meeting in Kuala Lumpur dismiss safety fears over the Airbus A330, expressing confidence of the plane’s reliability despite the Air France crash.
The AP quotes Emirates President Tim Clark as saying: “It is a very robust airplane. It has been flying for many years, clocking hundreds of millions of hours and there is absolutely no reason why there should be any question over this plane. It is one of the best flying today.”
Gulf Air Chief Executive Bjorn Naf said he was “not concerned at all” over the safety of the carrier’s fleet of 10 A330-200 planes but would wait for a directive from Airbus.
India’s Jet Airways Chairman Naresh Goyal echoed similar sentiments, saying he was confident of the safety of Jet’s 12 A330-200 planes. Eight are operated by Jet, while two are leased out. “No, I am not concerned. We are OK,” he said. “We will be guided by whatever Airbus tells us.”
Airbus Chief Operating Officer John Leahy told reporters that the A330-200 was a “reliable” plane and that it was too early to conclude otherwise until investigations were completed.
Air France Flight 447 had taken off from Rio de Janeiro bound for Paris. On board the 11-hour flight were 12 crew members and 216 passengers. The flight deck crew made their last radio contact with Brazilian air traffic controllers three hours after takeoff from Brazil’s Galeao-Antonio Carlos Jobim International Airport, reporting they were passing through an area of black, electrically-charged clouds. The planned flight path took the aircraft towards the Cape Verde Islands off West Africa, before turning north to France.
About 30 minutes later, the Airbus, flying at an altitude of 35,000 feet, encountered a severe storm in an area of the Atlantic known for turbulent weather systems. At the same time, the aircraft emitted a series of automatic messages via satellite indicating that its electrical system had failed and that they had lost cabin pressure.
The series of automatic messages indicated that the autopilot had disengaged, a computer system had switched to alternative power and that controls to keep the plane stable had been damaged. About three minutes later, more automatic messages reported the failure of systems to monitor air speed, altitude and direction.
The FDR and CVR include tracking beacons that activate in an accident. They broadcast a homing signal for about one month. But search teams must be within 4,000-5,000 feet of the devices to pick up the pinning And the air safety devices are probably deep at the bottom of the Atlantic Ocean.
A senior Brazilian military official said a long fuel slick on the surface of the ocean seemed to rule out a mid-air fire or explosion. But an Air Comet pilot who was flying in the area said he saw a bright flash of light about the time that Air France Flight 447 was in desperate trouble.
Air France is not yet convinced that faulty speed sensors were to blame for the loss of the A330, but it is replacing old sensors as a precaution, the airline’s CEO said last week.
Pierre-Henri Gourgeon told reporters that Air France was in a state of shock over the disaster and said he expected to have more information about what went wrong within a week.
At presstime, all that is known about the fatal crash constitutes circumstantial evidence, and the deep Atlantic water continues to cloak the devices that could solve the Mystery of Air France Flight 447.