Summary
We propose to adopt a new airworthiness directive (AD) for Diamond Aircraft Industries Model DA 40 and DA 40 F Airplanes. 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 fatigue strength found in the aft main spar does not ensure unlimited lifetime structural integrity. We are issuing this proposed AD to require actions to address the unsafe condition on these products.