Summary
We propose to adopt a new airworthiness directive (AD) for all HPH s. r.o. Models 304C, 304CZ, and 304CZ-17 sailplanes. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as the lack of a drain hole in the elevator control rod, which may allow water to accumulate in the control rod and lead to possible corrosion. This condition could cause the elevator control rod to fail, which could result in loss of control of the sailplane. We are issuing this proposed AD to require actions to address the unsafe condition on these products.