Airworthiness Directive · Amendment 39-13711 · Rolls-Royce Corporation (Formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) Models 250-C28, -C28B, and -C28C Turboshaft Engines
Rolls-Royce Corporation (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 (formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) (RRC) models 250-C28, -C28B, and -C28C turboshaft engines with third-stage turbine wheels, part number (P/N) 6899383, listed by serial number (SN) in the following Table 1:
| HX91922 | X523242 | X523281 |
| HX91923 | X523243 | X523283 |
| HX91925 | X523244 | X523284 |
| HX91926 | X523246 | X523287 |
| HX91928 | X523249 | X523288 |
| HX91929 | X523250 | X523289 |
| HX91930 | X523251 | X523290 |
| HX91932 | X523253 | X523291 |
| HX91934 | X523255 | X523292 |
| HX91936 | X523257 | X523293 |
| HX91937 | X523260 | X523294 |
| HX91939 | X523261 | X523295 |
| HX91940 | X523262 | X523296 |
| HX91960 | X523263 | X523297 |
| HX91962 | X523264 | X523298 |
| HX91966 | X523265 | X523300 |
| HX91976 | X523266 | X523305 |
| HX91977 | X523268 | X523309 |
| HX91979 | X523269 | X523313 |
| HX91980 | X523270 | X523315 |
| X523236 | X523271 | X523317 |
| X523237 | X523273 | X523319 |
| X523238 | X523276 | X523320 |
| X523239 | X523277 | N/A |
| X523241 | X523278 | N/A |
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 with certain serial number (SN) third-stage turbine wheels, part number (P/N) 6899383. This AD requires replacing certain SN third-stage turbine wheels, P/N 6899383, before reaching new reduced life limits. This AD results from three reports of third-stage turbine blade and shroud failures. We are issuing this AD to prevent loss of power and uncommanded engine shutdown due to failure of third-stage turbine blades and shrouds.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
(f) For any third-stage turbine wheel with fewer than 250 operating hours time since new (TSN) on the effective date of this AD, replace turbine wheel before accumulating 300 operating hours TSN.
(g) For any third-stage turbine wheel with 250 or more operating hours TSN on the effective date of this AD, replace turbine wheel before accumulating an additional 50 operating hours.
For the purposes of this AD, a replacement third-stage turbine wheel is a turbine wheel that does not have a SN listed in this AD.
(i) After the effective date of this AD, do not install third-stage turbine wheels that are listed in Table 1 of this AD, into any engine.
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
