AD FAA-2017-0640

We are adopting a new airworthiness directive (AD) for certain Diamond Aircraft Industries GmbH Model DA 42 airplanes. This AD requires installing engine exhaust pipe clamps with spring washers, repetitively inspecting the engine exhaust pipe clamps for cracks, and replacing the clamps if found cracked. This AD was prompted by cracks in the affected engine exhaust pipes, which could cause failure of the propeller regulating valve because of hot exhaust gases coming from the fractured pipes. We are issuing this AD to correct the unsafe condition on these products.