This article was provided by the FAA Aircraft Certification Office (ACO) Airframe, Propulsion and Services (ACE-118W) located in Wichita, Kansas.

Failing Parts: S2178-4 series hydraulic hoses used in the landing gear system.
Service Difficulty Reports (SDRs) are being received of landing gear hydraulic hose (P/N S2178-4 series) failures. In several cases, the failure resulted in a loss of hydraulic fluid, inability to extend the landing gear, and a gear-up landing.

An example of this is NTSB Report DEN01LA119 describing a Model 177RG. On July 1, 2001, the aircraft landed nose gear down/main gear up due to a nose gear actuator hose failure. After the accident the failed hose was identified as an S2178-4 series hose.

Cessna provided a Service Bulletin SEB 92-8 dated April 17, 1992, which mandated replacement of S2178-4 series hydraulic hoses with S2888 series hoses for certain Cessna Models 177RG, F177RG, 210, and P210.

Since an operator is not required to incorporate an SEB to maintain an airworthiness certificate, it appears that some operators (like the 177RG example) are not implementing SEB 92-8. To avoid in-flight loss of hydraulics due to S2178-4 hose failures, all owners, operators, and maintenance personal should verify Cessna SEB 92-8 has been incorporated on aircraft they fly and maintain.

If the SEB has not been completed, it is recommended that it be complied with immediately.