Summary
We propose to supersede Airworthiness Directive (AD) 2003-25- 07 for certain Airbus Model A319 and A320 series airplanes; and AD 2005-13-39 for certain Airbus Model A321 series airplanes. AD 2003-25- 07 currently requires a revision to the airplane flight manual (AFM) and replacement of both elevator aileron computers (ELACs) having L80 standards with new ELACs having L81 standards. AD 2005-13-39 currently requires a revision to the AFM, replacement of existing ELACs with ELACs having either L83 or L91 standards, as applicable; and a concurrent action. Since we issued AD 2003-25-07 and AD 2005-13-39, we have determined that new ELAC standards must be incorporated. The ELAC standards have been upgraded to version L97+, which implements enhanced angle-of-attack (AOA) monitoring to better detect AOA blockage, including multiple AOA blockages. This proposed AD would require replacing existing ELACs with new ELACs having L97+ standards or revising the software in an existing ELAC to the L97+ standards, as applicable, which would terminate the requirements of AD 2003-25-07 and AD 2005-13-39. This proposed AD would also add Airbus Model A318 series airplanes to the applicability. We are proposing this AD to prevent inadvertent activation of the AOA protections. Inadvertent activation of the AOA protections could result in a continuous nose down pitch rate that could result in reduced controllability of the airplane.