Procedural Changes Suggested Following Air France Flight 447 Accident

The French air accident investigating agency BEA has issued a series of safety recommendations stemming from the crash of Air France Flight 447 on June 1st, 2009. The interim report issued Friday follows a full readout from the Flight Data and Cockpit Voice recorders recovered in May of this year.

Among the findings in the report were that the captain’s departure from the cockpit occurred without clear operational instructions; the crew composition was in accordance with the operator’s procedures; and there was no explicit task-sharing between the two copilots. The data showed that the airplane was within its normal weight and balance envelope.

The findings also show that the autopilot disconnected while the air plane was flying at upper limit of a slightly turbulent cloud layer, and there was an inconsistency between the measured speeds, likely as a result of the obstruction of the Pitot probes in an ice crystal environment. The captain was resting at the time of the autopilot disconnect. Further, the agency says, even though they identified and announced the loss of airspeed indications, neither of the two copilots called the "Unreliable IAS" procedure, the copilots had received no high altitude training for the "Unreliable IAS" procedure and manual aircraft handling, no standard callouts regarding the differences in pitch attitude and vertical speed were made, and there is no CRM training for a crew made up of two copilots in a situation with a relief captain. The speed displayed on the left PFD reportedly remained invalid for 29 seconds.

The flight data also indicates that there was a problem with the indication of angle of attack, and that each time the stall warning was triggered, the angle of attack exceeded its theoretical trigger value. The data recorder shows that stall warning was triggered continuously for 54 seconds.

As a result, the BEA has issued a series of recommendations for procedure changes based on the findings. The first recommends that the regulatory authorities re-examine the content of training and check programs, and in particular make mandatory the creation of regular specific exercises aimed at manual airplane handling, as well as approach to and recovery from stall, including at high altitude. They further recommend that the regulatory authorities define additional criteria for access to the role of relief captain in order to ensure better task-sharing in case of relief crews.

The BEA additionally recommends that the regulatory authorities evaluate the relevance of requiring the presence of an angle of attack indicator directly accessible to pilots on board airplanes, require that aircraft undertaking public transport flights with passengers be equipped with an image recorder that makes it possible to observe the whole of the instrument panel, along with specific rules relating to the use of such recordings.

Finally, the BEA recommends that the regulatory authorities make mandatory the triggering of data transmission to facilitate localization when an emergency situation is detected on board, and that they explore a mandate for the activation of the Emergency Locator Transmitter (ELT) when an emergency situation is detected on board.

FMI: www.bea.aero/en/enquetes/flight.af.447/flight.af.447.php