# Allison 250-C20W - Type: Engine model (FAA registry) - Registry code: 03096 - Manufacturer (registry): ALLISON - Model: 250-C20W - Engine type: Turbo-shaft - Power: 420 hp - Data sheet: [TCDS E4CE](https://openairdocs.org/tcds/E4CE) (OpenAirDocs) - Holder: Rolls-Royce Corporation - Installed in: 3 registered aircraft - Page: https://openairdocs.org/engine/allison-250-c20w Model codes come from the FAA registry's reference file. ## ADs that may apply (OpenAirDocs) Matched to this engine model by model name and maker. Each AD's applicability may narrow it by serial number, part number or equipment. - [AD 2022-10-06](https://openairdocs.org/ad/2022-10-06): Turbine Section · Rolls-Royce 250-C20, 250-C20B, 250-C20C (T63-A-720) and 9 more. Effective Jun 28, 2022 - [AD 2018-13-01](https://openairdocs.org/ad/2018-13-01): Turbine Governor · Rolls-Royce 250-C10 (T63-A-5), 250-C18, 250-C18A and 24 more. Effective Aug 16, 2018 - [AD 2006-16-04](https://openairdocs.org/ad/2006-16-04): Inspection of the fuel nozzle screen · Rolls-Royce 250-B15A, 250-B15E, 250-B15G and 43 more. Effective Sep 7, 2006 - [AD 2006-13-06](https://openairdocs.org/ad/2006-13-06): Gas producer rotor assembly tie bolts · Rolls-Royce 250-B17, 250-B17B, 250-B17C and 16 more. Effective Jul 26, 2006 - [AD 2005-10-13](https://openairdocs.org/ad/2005-10-13): Turbine energy absorbing ring · Rolls-Royce 250-B17B, 250-B17C, 250-B17D and 7 more. Effective Jun 22, 2005 - [AD 2004-26-09](https://openairdocs.org/ad/2004-26-09): Compressor Adaptor Couplings · Rolls-Royce 250-B17, 250-B17B, 250-B17C and 8 more. Effective Feb 8, 2005 - [AD 2001-24-12](https://openairdocs.org/ad/2001-24-12): Helical Torquemeter Gearshaft Assembly · Rolls-Royce 250-B17, 250-B17C, 250-B17D and 13 more. Effective Dec 19, 2001 - [AD 98-24-28](https://openairdocs.org/ad/98-24-28): Main Fuel Control Bellows · Rolls-Royce 250-B15A, 250-B15E, 250-B15G and 36 more. Effective Jan 7, 1999 - [AD 96-19-01](https://openairdocs.org/ad/96-19-01): Superior Air Parts Manufacture Approval (PMA) Bearings · Rolls-Royce 250-B15G, 250-B17F, 250-B17F/1 and 17 more. Effective Sep 26, 1996 - [AD 88-17-01](https://openairdocs.org/ad/88-17-01): Fuel Controls · Rolls-Royce 250-B17, 250-B17B, 250-B17C and 26 more. Effective Mar 1, 1989 - [AD 82-24-05](https://openairdocs.org/ad/82-24-05): Control Assembly and Power Turbine Governor Assembly · Rolls-Royce 250-B15A, 250-B15E, 250-B15G and 43 more. Effective Nov 26, 1982 - [AD 77-15-12](https://openairdocs.org/ad/77-15-12): Power Turbine Coupling Nut · Rolls-Royce 250-B15A, 250-B15E, 250-B15G and 23 more. Effective Sep 23, 1977 Historical (superseded or no longer in force): - [AD 2017-18-14](https://openairdocs.org/ad/2017-18-14) (historical): Turbine Section · Rolls-Royce 250-C20, 250-C20B, 250-C20F and 8 more. Effective Oct 13, 2017 - [AD 2015-02-22](https://openairdocs.org/ad/2015-02-22) (historical): Repetitive visual inspections · Rolls-Royce 250-B17, 250-B17B, 250-B17C and 15 more. Effective Mar 9, 2015 - [AD 2004-24-09](https://openairdocs.org/ad/2004-24-09) (historical): Fuel nozzle · Rolls-Royce 250-B15A, 250-B15E, 250-B15G and 40 more. Effective Jan 5, 2005 - [AD 2001-20-51](https://openairdocs.org/ad/2001-20-51) (historical): Helical Torquemeter Gearshaft Assembly · 250-B17, 250-B17C, 250-B17D and 12 more ## Registered aircraft (3) - [N434ST](https://openairdocs.org/aircraft/N434ST): [Schweizer Rsg LLC](https://openairdocs.org/faa-owner/SCHWEIZER%20RSG%20LLC), [Fort Worth, TX](https://openairdocs.org/faa-place/TX/Fort%20Worth), S/N 0010 - [N480DD](https://openairdocs.org/aircraft/N480DD): [Butler William J II](https://openairdocs.org/faa-owner/BUTLER%20WILLIAM%20J%20II), [Juntura, OR](https://openairdocs.org/faa-place/OR/Juntura), built 1996, S/N 5017 - [N480MM](https://openairdocs.org/aircraft/N480MM): [Aviation LLC](https://openairdocs.org/faa-owner/AVIATION%20LLC), [Madison, WI](https://openairdocs.org/faa-place/WI/Madison), built 2001, S/N 5040 ## NTSB investigations None matched to aircraft with this engine model. ## FAA accident and incident reports None matched to aircraft with this engine model. ## Service difficulty reports (3) As reported by operators and repair stations, by the model named in the report. - [SDR 2012FA0000327](https://openairdocs.org/sdr/2012FA0000327), May 9, 2012: IMPELLER. CRACKED. OIL COOLER IMPELLER WAS INSPECTED FOR CRACKS IN THE BLADE/SHOUD REGION IAW MFG RECOMMENDATIONS EVERY 100 HRS OF OPERATION. 2 CRACKS WERE CONFIRMED AND SEVERAL O - [SDR 2012FA0000328](https://openairdocs.org/sdr/2012FA0000328), May 9, 2012: IMPELLER. CRACKED. OIL COOLER IMPELLER WAS INSPECTED FOR CRACKS IN THE BLADE/SHOUD REGION IAW MFG RECOMMENDATIONS EVERY 100 HOURS OF OPERATION. 2 CRACKS WERE CONFIRMED AND SEVERAL - [SDR 2008FA0000863](https://openairdocs.org/sdr/2008FA0000863), Nov 10, 2008: PINION GEAR. WORN. DURING SHUT-DOWN, PILOTS REPORTED CLUNKING NOISE. UPON FURTHER INSPECTION, NOISE WAS LOCATED AT UPPER PULLEY SPRAG CLUTCH AREA. REMOVED UPPER PULLEY AND FOUND M ## STCs that may be installed (OpenAirDocs) (4) Approved for this engine model: the STC's model list names it on its data sheet, or a series that includes it. In force first, then newest. The registry doesn't record which STCs an aircraft has. - [STC SE5511NM](https://openairdocs.org/stc/SE5511NM): Installation of compressor discharge pressue (PC) valve. Bell Helicopter Textron Inc - [STC SE00014EN](https://openairdocs.org/stc/SE00014EN): Installation of the Pratt & Whitney Engine Services, Inc. CrossCheck Engine Monitor Kit P/N HUMS-K-071-1, Rev. A on the specified PT6A engine models and kit P/N HUMS-K-071-2 on the specified A250 engine models. Pratt & Whitney Engine Services Inc - [STC SE00027EN](https://openairdocs.org/stc/SE00027EN): Installation of Pratt & Whitney Engine Services Inc. Intellistart plus electronic control unit (ECU), P/N DPU-K-010 on the specified 250 engine models. Pratt & Whitney Engine Services Inc - [STC ST00037AT](https://openairdocs.org/stc/ST00037AT): Unison igniter plugs, P/N 9044400-1. Unison Industries --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.