My 114B maintenance manuel notes: replace all flexible fluid carrying hoses every 10 years or sooner if deterioration is evident. Replace all flexible hydraulic hoses every 5 years or sooner if deterioration is evident. The plane is not for hire. what is normal?? Also does the dorsal fin need to come off for an inspection? Mine appears to have been sealed ( @ the factory) where it fastens to the fuselage and is not sealed where it is fastened to the tail. this appears to have been to keep water out.