EASA SIB CE-18-32
Textron Aviation Model 208B Aeroplanes - Engine Oil System (Airframe Furnished) - Flapper Check Valve Failure
Summary
The Special Airworthiness Information Bulletin SAIB: CE-18-32 is an FAA informational bulletin addressing the failure of the engine oil system flapper check valve on Textron Aviation Model 208B airplanes equipped with the PT6A-140 engine. It alerts owners, operators, and maintenance personnel about failures of check valve part number C100490-1 on certain serial numbers of the 208B EX model. The bulletin provides details on the issue without mandating regulatory action.
What Changed
This bulletin introduces awareness of a latent failure condition involving the flapper check valve in the engine oil system of Textron Model 208B EX airplanes. It reports three known failure events and clarifies that no unsafe condition currently warrants an airworthiness directive under 14 CFR part 39. The bulletin also corrects a misidentification of the check valve in the maintenance manual.
Why It Matters
This information is important for aviation professionals because failure of the flapper check valve can lead to increased oil temperatures and potential engine oil system blockage, which may affect engine performance and safety. Operators and maintenance teams need to monitor oil temperature indications closely to detect possible valve failure early. Understanding this issue helps in proactive maintenance and avoiding in-flight engine complications.
What To Do
Operators should monitor for signs of flapper check valve failure, such as steadily increasing oil temperatures or operation in caution and warning ranges. Any check valve with part number C100490-1 that has 1800 or more hours time in service should be replaced until further investigation is completed. Removed check valves should be returned to Textron Aviation Customer Service for evaluation.