Summary
We propose to supersede Airworthiness Directive (AD) 2008-12- 16, which applies to certain M7 Aerospace LP SA226 and SA227 series airplanes. AD 2008-12-16 currently requires you to inspect wires and tube assemblies for chafing, arcing, or insufficient clearance between components. If chafing, arcing, or insufficient clearance between components is found, AD 2008-12-16 requires you to clear, repair, and/ or replace all chafed wires, components, and tube assemblies. AD 2008- 12-16 also requires you to cover the four-gauge wires leaving the battery box with firesleeving and secure them with a clamp. Since we issued AD 2008-12-16, M7 Aerospace LP has notified us that Model SA227- BC (C-26A) was inadvertently left out of the Applicability section of the AD and they updated some of the service information due to parts availability. Operators have also identified issues with model applicability that needed clarification. Consequently, this proposed AD would retain the actions of AD 2008-12-16, add Model SA227-BC (C-26A) to the Applicability section, and regroup the models for clarification. We are proposing this AD to detect and correct chafing of electrical wires, components, and tube assemblies. This condition could result in arcing of exposed wires with consequent burning of a hole in a hydraulic line or the bleed air line. This failure could lead to a hydraulic fluid leak and a possible fire in the engine nacelle compartment.