Summary
This document proposes to adopt a new airworthiness directive (AD) that would apply to certain MORAVAN a.s. (Moravan) Models Z-143L and Z-242L airplanes. This proposed AD would require you to modify the engine secondary vent line. This proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the Czech Republic. The actions specified by this proposed AD are intended to prevent the engine crankcase ventilation lines from freezing during flight in cold weather (winter) conditions, which could result in oil leaking from the engine. Such a condition could lead to engine failure.