Airworthiness Directives; Hoffmann GmbH & Co. KG Propellers

FAA / Federal Register · 2020-26765

The FAA is adopting a new airworthiness directive (AD) for all Hoffmann GmbH & Co. KG (Hoffmann) model HO-V 72 propellers. This AD was prompted by reports of cracks at different positions on two affected propeller hubs. This AD requires amending the existing aircraft flight manual (AFM) with abnormal propeller vibration instructions. This AD requires visual inspection and non-destructive test (NDT) inspection of the propeller hub and, depending on the results of the inspections, replacement of the propeller hub with a part eligible for installation. This AD also requires replacement of the propeller hub before exceeding 30 years since the date of manufacture or within 30 days after the effective date of this AD, whichever occurs later. The FAA is issuing this AD to address the unsafe condition on these products.