AD FAA-2007-0051

We are superseding airworthiness directive (AD) 2009-16-03 for certain Continental Motors, Inc. (CMI) IO-520, TSIO-520, and IO-550 series reciprocating engines, with certain SAP replacement parts manufacturer approval (PMA) investment cast cylinder assemblies installed. AD 2009-16-03 required initial and repetitive inspections and compression tests to detect cracks in those cylinders. This new AD requires that additional engines be added to the applicability. This AD was prompted by the need to add to the applicability all other engine models approved for the use of CMI 520 and 550 cylinder assemblies, such as the CMI 470 series engines when modified by supplemental type certificate (STC), with affected SAP investment cast cylinder assemblies installed. We are issuing this AD to prevent the separation of the cylinder head, damage to the engine, and damage to the airplane.