Summary
We propose to adopt a new airworthiness directive (AD) for all Airbus Model A318, A319, A320, and A321 series airplanes. This proposed AD was prompted by a report that an investigation showed that when a certain combination of a target/proximity sensor serial number is installed on a flap interconnecting strut, a ``target FAR'' signal cannot be detected when it reaches the mechanical end stop of the interconnecting strut. This proposed AD would require an inspection to determine the part number (P/N) of the interconnecting struts installed on the wings, identifying the P/N and the serial number (S/N) of the associated target and proximity sensor if applicable, and replacing or re-identifying the flap interconnecting strut if applicable. We are proposing this AD to detect and correct a latent failure of the flap down drive disconnection due to an already-failed interconnecting strut sensor, which could result in asymmetric flap panel movement and consequent loss of control of the airplane.