Transport i infrastruktura · 14/11/1994

Airworthiness Directives; Airbus Model A320 Series Airplanes

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Airbus Model A320 series airplanes. This proposal would require replacement of the check valves of the thrust reverser with modified valves on certain airplane configurations and the replacement of the manual control valves of the thrust reverser with modified valves on certain other airplane configurations. This proposal is prompted by recent engineering analysis, which revealed that if the non-return valve installed on the hydraulic return line of the thrust reverser were to jam in the closed position, it could cause pressurization of the Hydraulic Control Unit (HCU). The actions specified by the proposed AD are intended to prevent possible pressurization of the HCU, due to jamming of the non-return valve in the hydraulic return line, and consequent deployment of a thrust reverser during flight, which could affect the controllability of the airplane.