Air France Flight 447 Sent Out 24 Automated Messages - Officials Reviewing The Speed Sensor Data

Air France Flight 447 Likely Broke Apart In Mid Air - Its The Worst Air Disaster In Air France’s History 

By Bill Goldston

June 8, 2009, Update- Air France flight 447 an Airbus A330-200 departed Rio de Janeiro-Galeăo International Airport, Brazil at 6:30 PM Eastern Standard time on Sunday, May 31, 2009. The flight was to land at Charles de Gaulle International Airport, Paris, France. The last verbal communication by pilots to air traffic controllers was three hours into their flight.  Brazil. The pilots reported to Brazilian air traffic control that they were experiencing extremely heavy turbulence was in an electrical storm. 14 minutes later the aircraft automatic messaging systems alerted air traffic control officials of a loss in cabin pressure and an electrical system malfunction.

Air France Flight 447 sent out 24 automated system (ACARS) malfunction messages. One of the more important messages indicated inconsistent speed readings from the A330's sensors while in flight. In July 2001, the FAA adopted a new airworthiness directive (AD) applicable to all Airbus Model A330 and A340 series airplanes. The AD required revising the Airplane Flight Manual to advise flight crew of appropriate procedures to follow in the event of lost or erroneous airspeed indications. The action was necessary to prevent inadvertent flight operations outside the normal flight envelope. This action was intended to address the identified unsafe condition of the speed reading sensor.

The Direction Generale de l'Aviation Civile (DGAC), which is the airworthiness authority for France, notified the FAA that an unsafe condition may exist on all Airbus Model A330 and A340 series airplanes. The DGAC advises that pilots have reported several cases of sudden fluctuation of airspeed indications (including calibrated airspeed, true airspeed, and Mach) in cruise during severe icing conditions. Lost or erroneous airspeed indications could result in lack of sufficient information for the flight crew to safely operate the airplane, and consequent inadvertent excursions outside the normal flight envelope.

A revision of Airplane Flight Manual (AFM) was to include "In the event of erroneous airspeed in flight or at take-off, or if the airspeed indication is lost, accomplish the following:  
 

Unreliable airspeed may be caused by a radome destruction or obstructed pitots. If the failure is due to radome destruction, the drag will be increased and therefore N1 must be increased by 3% in cruise or 1.5% in approach.  

Switch OFF the AP/FD and A/THR  

Maintain flaps/slats in current configuration  

Check that speedbrakes are retracted when airborne, select landing gear up

•        With slats extended--Apply MCT thrust and set the pitch attitude to 12.5 deg.

•        In clean configuration--Apply CLB thrust

•        When below FL100, set the pitch attitude to 10 deg.

•    When above FL100, set the pitch attitude to 5 deg.

 Note: Respect Stall warning if in alternate law  

When the flight path is stabilized, set the PROBE WINDOW HEAT to ON.  

Adjust pitch attitude and thrust regarding flight phase and aircraft configuration to obtain and maintain target speed.  

In the event of a double pitot probe heat failure, accomplish the following:  

Double Probe Heat Failure  

If icing conditions cannot be avoided: Switch OFF one of the affected ADRs"