Airbus operators are being instructed to remove conic plates on angle-of-attack sensors and replace them with flat plates, to address a pressing flight-control issue which became apparent during an incident involving an A330.
The incident is still under investigation but the conic plates are suspected to have contributed to the blockage of all angle-of-attack probes on the twinjet.
Conic plates - which are manufactured by Goodrich and Thales - are circular structures, with the appearance of a shallow cone, which surround the angle-of-attack sensors located on the forward fuselage.
Airbus has developed a service bulletin, which is being mandated by the European Aviation Safety Agency, to replace these with a circular flat plate which lies flush with the fuselage surface.
The airframer had previously had to develop an emergency flight procedure to deal with the sensor blockage. Replacement of the plates permits the procedure to be removed from the aircraft's flight manual.
EASA's directive requires all conic plates to be removed, and flat plates installed, within five months.
While the modification was originally aimed at A330 and A340 aircraft, the use of conic plates on the A320 has resulted in EASA's extending the replacement order to all members of Airbus's single-aisle family.