. All of the aircraft used Pitot Tubes designed and manufactured by Thales, purportedly to Airbus specifications. All of the Pitot Tube assemblies were ordered to be replaced in the aftermath of the accident, but most operators replaced them with a newer model Thales unit. Airbus and the JAA (Europe's version of the FAA) have ordered operators to replace two of the three Pitot Tube Assemblies on each aircraft with competing units designed and built by Goodrich Corp. There is no word yet if the FAA is issuing an Airworthines Directive to that effect. But of course this would only be mandated by aircraft in The US, and Europe, other countries may or may not chose to make the the change mandatory for aircraft operated from their territories.
The Northwest incidents were discovered when Delta Air Lines, which merged with Northwest last year, reviewed archived flight data for its fleet of 32 Airbus A330s, the people close to the inquiry said. All of the incidents took place in the Intertropical Convergence Zone, which extends from 5 degrees north of the equator to 5 degrees south, and all the planes involved landed safely, they said.
Aviation experts said the discovery could provide clues to what caused Air France Flight 447 to crash into the Atlantic en route from Brazil to France on June 1, and what might be done to prevent future tragedies.
French investigators have focused on the possibility that Flight 447's sensors iced over and sent false speed information to the computers as the plane ran into a thunderstorm at about 35,000 feet.
An important part of the investigation focuses on 24 automatic messages the plane sent during its final minutes. They show the autopilot was not working, but it is unclear whether the pilots shut it off or whether it shut down because of the conflicting airspeed readings.
Three weeks after the Air France crash, the U.S. National Transportation Safety Board announced it was investigating two other A330 flights that experienced a loss of airspeed data.
The most recent was on June 23, when a Northwest flight hit rain and turbulence while on autopilot outside of Kagoshima, Japan. According to an NTSB report, speed data began to fluctuate. The plane alerted pilots it was going too fast. Autopilot and other systems began shutting down, putting nearly all the plane's control in the hands of the pilot, something that usually happens only in emergencies.
In May, a plane belonging to Brazilian company TAM Airlines lost airspeed and altitude data while flying from Miami to Sao Paulo, Brazil. Autopilot and automatic power also shut down and the pilot took over, according to an NTSB report. The computer systems came back about five minutes later.
"These two cases we know were dealt with effectively by the crew, and we think this happened in Air France and maybe wasn't dealt with effectively," said Bill Voss, president of the Flight Safety F,oundation in Alexandria, Va., an aviation safety think tank.
But of course Delta/Northwest isn't the only US carrier flying the deathtraps.
You can't find what you refuse to see.