Airworthiness Directives; Turbomeca Artouste III Series Turboshaft Engines

The FAA is superseding an existing airworthiness directive (AD) for Turbomeca Artouste III series turboshaft engines. That AD currently requires smoke emission checks after every ground engine shutdown, and if necessary, additional checks and possibly removing the engine from service. That action also requires inspection of central labyrinths not previously inspected, or not replaced after the engine logged 1,500 operating hours, and, replacement if necessary. That action also requires the removal of injection wheels at a new lower life limit. This AD includes the same requirements as AD 2002-22-11, but reduces the compliance time for the initial inspection of the central labyrinth and adds repetitive inspections of the central labyrinth. This AD results from reports and analyses of in-flight engine shutdowns occurring since we issued AD 2002-22-11. We are issuing this AD to prevent injection wheel cracks and excessive central labyrinth wear, which could result in an in-flight engine shutdown and possible loss of the helicopter.