The Airbus A320neo has been found to be potentially subject to an angle-of-attack protection weakness, which, under certain circumstances, could lead to excessive pitch and higher flight crew workload conditions. The notification by the European Union Aviation Safety Agency (EASA) comes weeks after a similar excessive pitch anomaly was discovered on the A321neo.
According to the Airworthiness Directive (AD), issued by the EASA on July 31, 2019, a “reduced efficiency” of the A320neo angle-of-attack (AOA) protection under certain flight configurations, and in combination with specific commanded maneuvers from the flight crew, could lead to excessive pitch attitudes, possibly resulting in increased workload.
This “potentially unsafe” condition, although never encountered during operations, was discovered during analysis and laboratory testing of the A320neo flight control laws, the EASA says.
Airbus has issued temporary revisions to the A320neo flight manual (AFM TR) to address the situation, and the EASA has ordered operators of the type to revise their manuals accordingly. The revisions limit the center-of-gravity envelope for the plane. In addition, the manufacturer has provided loading recommendations.
The regulator’s instructions for the type come after a similar issue was found in another member of the Airbus A320 Family, the A321neo. In that case, Airbus’ temporary revisions to the A321neo flight manuals were necessitated after analysis of the elevator and aileron computer installed on the aircraft. A behavior anomaly in these computer units was also found to potentially lead to an excessive pitch scenario.
In the AD, issued by the EASA on July 17, 2019, operators of the A321neo were also urged to update their flight manuals according to temporary revisions developed by Airbus. The directive, considered as an “interim action”, has since been revised and published again on July 31, 2019. Operators must comply with a 30 day ‘window’ starting August 7, 2019.
As for the instructions regarding the A320neo, the AD comes into effect on August 14, 2019, already, with the commentary period postponed after its publication.