Airworthiness Directives; Diamond Aircraft Industries GmbH
Key claim: The FAA is adopting an airworthiness directive for Diamond DA 42, DA 42 NG, and DA 42 M-NG airplanes requiring AFM revisions, repetitive inspections of NLG hydraulic actuator rod ends, and replacement when cracked or damaged to prevent uncommanded rudder deflection.
Abstract
(Rule · Transportation Department, Federal Aviation Administration) The FAA is adopting a new airworthiness directive (AD) for all Diamond Aircraft Industries GmbH (DAI) Model DA 42, DA 42 NG, and DA 42 M-NG airplanes. This AD was prompted by occurrences of uncommanded rudder deflection caused by a cracked nose landing gear (NLG) hydraulic actuator rod end, which could lead to failure of the NLG actuator and interference with the rudder control system, forcing the rudder into left-hand deflection. This AD requires revising the existing airplane flight manual (AFM) for your airplane to provide the flight crew with revised operating limitations, repetitively inspecting certain NLG hydraulic actuator rod ends for cracks, deformation, corrosion, damage, and free movement of the spherical bearing, and depending on the results of any inspection, replacing the affected NLG hydraulic actuator rod end with a serviceable part. This AD also prohibits the installation of an affected NLG hydraulic actuator rod end unless certain conditions are met. The FAA is issuing this AD to address the unsafe condition on these products.
Why this matters
Uncommanded rudder deflection linked to a nose landing gear hydraulic actuator rod end represents a safety-of-flight hazard on a widely used light twin trainer, so the AD’s inspection-and-replace regime plus AFM changes directly affect operators of the DA 42 family. It is another routine data point in the ongoing pattern of FAA final-rule ADs targeting specific mechanical failure modes uncovered in service.