Airworthiness Directive · Amendment 39-14305 · Rolls-Royce Corporation (RRC) (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) Models 250-C28, -C28B, and -C28C Turboshaft Engines
Rolls-Royce Corporation (RRC) (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) Models 250-C28, -C28B, and -C28C Turboshaft Engines
This AD applies to Rolls-Royce Corporation (RRC) (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) models 250-C28, -C28B, and -C28C turboshaft engines. These engines are installed on, but not limited to, Bell Helicopter Textron 206L-1; Eurocopter Deutschland BO 105 LS A-1; and Eurocopter Canada BO 105 LS A-3 helicopters.
The FAA is adopting a new airworthiness directive (AD) for Rolls-Royce Corporation (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) (RRC) Models 250-C28, - C28B, and -C28C turboshaft engines. This AD requires a onetime visual inspection of the seal joint in each passage between airfoils at the hub and shroud of third-stage turbine wheels, part number (P/N) 6899383. This AD results from reports of three failed third-stage turbine wheels and from the manufacturer's analysis of those failures. We are issuing this AD to prevent loss of power and uncommanded engine shutdown due to failure of the third-stage turbine wheel.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
For third-stage turbine wheels, part number (P/N) 6899383, with fewer than 3,000 hours time-since-new (TSN), inspect the next time the third-stage turbine wheel is directly available for removal, at the next turbine overhaul, or by April 30, 2007, whichever occurs sooner.
(g) For third-stage turbine wheels, P/N 6899383, with 3,000 hours or more TSN, inspect within 300 hours or by April 30, 2007, whichever occurs sooner.
(h) Remove the third-stage turbine wheel and perform a onetime visual inspection of the seal joint in each passage between airfoils at the hub and shroud. Seal joint evidence must not be present within blade fillet radii. See Figure 1 of this AD for reference.
(i) Remove from service any turbine wheel that has seal joint evidence present within blade fillet radii.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Engines
