AD 2021-20-21 Required An Adjustment Of The Engine Push-Pull Control And Replacement Of The Beta Switch

The FAA is superseding Airworthiness Directive (AD) 2018-16-10 which applied to certain GE Aviation Czech s.r.o. (GEAC) H80-200 model turboprop engines.

AD 2018-16-10 required an adjustment of the engine push-pull control and replacement of the beta switch to prevent the propeller governor control from going to a negative thrust position. This AD requires an initial inspection and adjustment of the engine push-pull control and replacement of the beta switch. This AD also requires inspection and adjustment of the engine push-pull control after any maintenance, repair or modification that affects the push-pull control and installation of an improved push-pull control. This AD also expands the applicability to include GEAC H85-200 model turboprop engines with Avia Propeller AV-725 propellers installed. This AD was prompted by an accident involving an Aircraft Industries (AI) L 410 UVP-E20 airplane caused by one propeller going to a negative thrust position during the landing approach. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective November 18, 2021.

Supplementary Information: The FAA issued AD 2018-16-10, Amendment 39-19350 (83 FR 43742, August 28, 2018) (AD 2018-16-10), for certain GE Aviation Czech H80-200 model turboprop engines. AD 2018-16-10 required replacement of the beta switch and adjustment of the engine push-pull control to prevent the propeller governor control from going to a negative thrust position. AD 2018-16-10 resulted from an accident involving an AI L 410 UVP-E20 airplane caused by one propeller going to a negative thrust position during the landing approach. The FAA issued AD 2018-16-10 to require engine modification to prevent asymmetric thrust. The unsafe condition, if not addressed, could result in failure of the beta switch, loss of engine thrust control, and reduced control of the airplane.

FMI: www.regulations.gov