AD 2020-18-08 Continues To Require Inspecting Those Previously Affected Hoses

The FAA is superseding Airworthiness Directive (AD) 2019-12-18 for Robinson Helicopter Company (Robinson) Model R44 II helicopters.

AD 2019-12-18 required inspecting certain engine air induction hoses (hoses) and replacing any hose that was not airworthy. AD 2019-12-18 also prohibited the installation of certain hoses. This AD continues to require inspecting those previously affected hoses and amends the applicability, clarifies an inspection requirement, adds a requirement to repeat the inspection, and expands the installation prohibition. This AD was prompted by an additional report of separation between the outer and inner hose layers. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective August 27, 2020.

Supplementary Information: The FAA issued AD 2019-12-18, Amendment 39-19673 (84 FR 32028, July 5, 2019) (“AD 2019-12-18”), for Robinson Model R44 II helicopters. AD 2019-12-18 required, for helicopter serial numbers (S/Ns) 14248 through 14268 and 14270 through 14286 and helicopters with a hose part number (P/N) A785-31 installed after April 30, 2018, inspecting the inside of the hose for separation between the outer and inner layers and flexing the hose in all directions while listening for a crinkling sound, which is an indication of separation. If there was any separation or a crinkling sound, AD 2019-12-18 required replacing the hose before further flight. If there was no separation and no crinkling sound, AD 2019-12-18 required replacing the hose within 50 hours time-in-service (TIS). Finally, AD 2019-12-18 prohibited installing hose P/N A785-31 marked with code 1Q18 on any helicopter.

AD 2019-12-18 resulted from 12 reports, including an accident on April 4, 2019, of separation between the outer and inner layers of the orange silicone hose out of a suspected population of 100 hoses traced to a specific manufacturing batch marked by code 1Q18 (1st quarter of 2018). The separation of the silicone layers, if not addressed, could result in blockage of air flow to the engine, engine stoppage, and subsequent loss of control of the helicopter. Accordingly, the FAA issued AD 2019-12-18 to address the unsafe condition on these products.

FMI: www.regulations.gov