NTSB probing Airbus instrument problems

WASHINGTON, June 27 (UPI) -- The U.S. National Transportation Safety Board is investigating two cases of instrument failure on Airbus A330 planes, officials said.

The probe follows the crash of an A330 over the Atlantic. Air France Flight 447 from Rio de Janeiro to Paris went down in the Atlantic Ocean and investigators suspect airspeed sensors may have failed.

On May 21, instruments on a TAM Airlines Airbus stopped providing speed and altitude data while the plane was en route from Miami to Sao Paulo, CNN reported. The crew was able to switch to backups.

The crew of a Northwest Airlines flight from Hong Kong to Tokyo experienced similar problems June 23, the NTSB said.

Paul-Louis Arslanian, head of the French agency investigating the Air France crash, said the plane sent 24 error messages in the few minutes before it went down. The flight data recorders have not been recovered.