AD 96-24-07 61 FR 59326

This amendment adopts a new airworthiness directive (AD) that applies to certain HOAC Austria Model DV-20 Katana airplanes. This action requires replacing the muffler with one of improved design, installing a heat shield around the exhaust system endpipe, and adjusting the airplane weight and balance. This AD results from reports of cracks in the welding joint that connects the exhaust system endpipe to the muffler on three of the affected airplanes. The actions specified by this AD are intended to prevent separation of the exhaust system endpipe from the muffler because of cracks in the welding that connects these parts, which could result in heat damage to the electrical system and engine controls.