# Allison 250-C20R - Type: Engine model (FAA registry) - Registry code: 03090 - Manufacturer (registry): ALLISON - Model: 250-C20R - Engine type: Turbo-shaft - Power: 450 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-c20r 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 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 Effective Sep 23, 1977 Historical (superseded or no longer in force): - [AD 2017-18-14](https://openairdocs.org/ad/2017-18-14) (historical): Turbine Section · Rolls-Royce 250-C20, 250-C20B, 250-C20F and 8 more.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) - [N355HR](https://openairdocs.org/aircraft/N355HR): [Next Level Aviation LLC](https://openairdocs.org/faa-owner/NEXT%20LEVEL%20AVIATION%20LLC), [Pflugerville, TX](https://openairdocs.org/faa-place/TX/Pflugerville), built 1991, S/N 5473 - [N5052H](https://openairdocs.org/aircraft/N5052H): [Obrien Helicopters Inc](https://openairdocs.org/faa-owner/OBRIEN%20HELICOPTERS%20INC), [Lehigh Acres, FL](https://openairdocs.org/faa-place/FL/Lehigh%20Acres), built 1990, S/N 4115 - [N98EA](https://openairdocs.org/aircraft/N98EA): [On Target Applicators LLC](https://openairdocs.org/faa-owner/ON%20TARGET%20APPLICATORS%20LLC), [Monticello, IN](https://openairdocs.org/faa-place/IN/Monticello), built 1973, S/N 935 ## 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 (111, newest 50) As reported by operators and repair stations, by the model named in the report. - [SDR X2RA2020010800000](https://openairdocs.org/sdr/X2RA2020010800000), Nov 7, 2019: GOVERNOR. FAILED. LOW SIDE GOVERNOR FAILURE, EPO ILLUMINATED, N1, N2, TORQUE DROP INDICATOR LOSS OF POWER. PILOT LANDED IMMEDIATELY WITHOUT INCIDENT. UPON POWER DOWN THE PILOT LO - [SDR CA190704013](https://openairdocs.org/sdr/CA190704013), Jul 3, 2019: LOCK PIN. INOPERATIVE. (CAN) WE RECENTLY BOUGHT AND INSTALLED THE DART TAIL ROTOR PEDAL LOCK OUT KIT IN OUR BELL 206L AND 407.. YESTERDAY, IN FLIGHT THE PASSENGER TOUCHED THE AFT END - [SDR CA160108005](https://openairdocs.org/sdr/CA160108005), Jan 4, 2016: TURBINE. FAILED. (CAN) TURBINE HAD A CATASTROPHIC FAILURE, ACFT AUTO ROTATED TO A CLEARING. 1 MAIN ROTOR BLADE RECEIVED MINOR DAMAGE FROM TURBINE PIECES, NO OTHER ACFT DAMAGE. - [SDR CA151007019](https://openairdocs.org/sdr/CA151007019), Oct 7, 2015: GEARBOX. MAKING METAL. (CAN) DURING SHUTDOWN, PILOT REPORTED AN UNFAMILIAR METALLIC NOISE FOLLOWED SHORTLY BY ILLUMINATION OF THE COMBINING GEARBOX CHIP LIGHT. INSPECTION OF THE CHIP - [SDR CA150421002](https://openairdocs.org/sdr/CA150421002), Apr 9, 2015: STARTER GEN. FAILED. (CAN) SPECIFIC PART CAUSING DIFFICULTY: STARTER GENERATOR VOLTAGE REGULATOR. STARTER GENERATOR WENT OFFLINE. REMOVED BOTH STARTER GENERATOR & VOLTAGE REGULATOR - [SDR CA150217005](https://openairdocs.org/sdr/CA150217005), Jan 29, 2015: STIFFENER. CRACKED. (CAN) FOUND 3 CM CURVED HORIZONTAL CRACK ALONG LT LOWER SIDE AND 3.5 CM CURVED HORIZONTAL CRACK ALONG RT SIDE OF HORIZONTAL STIFFENER. ALSO, FOUND 0.5 CM CRACK - [SDR CA150122007](https://openairdocs.org/sdr/CA150122007), Oct 14, 2014: TURBINE WHEEL. CRACKED. (CAN) THE PILOT HAD REPORTED N2 LOCKUP. DURING MAINTENANCE THE ENGINE WAS DISASSEMBLED TO HAVE THE ENGINE GEARBOX REPAIRED AND TO SEND THE TURBINE FOR INSPECTIO - [SDR CA140918013](https://openairdocs.org/sdr/CA140918013), Sep 16, 2014: NOZZLE. CRACKED. (CAN) TURBINE MODULE SENT IN FOR O/H. DURING PART INSPECTION AFTER UNIT DISASSEMBLY THE NOZZLE WAS SCRAPPED FOR OUTER BAND CRACKS AS WELL AS FILLET CRACK AT THE - [SDR CA140717014](https://openairdocs.org/sdr/CA140717014), Jul 4, 2014: FUEL CONTROL. MALFUNCTIONED. (CAN) THIS ACFT WAS OUT FLYING FOR THE DAY AND WHEN IT RETURNED TO BASE AND THE PIC DECREASED THE THROTTLE TO GROUND IDLE THE ENGINE WENT PAST IDLE AND SHUTDOWN - [SDR CA140627006](https://openairdocs.org/sdr/CA140627006), Jun 19, 2014: STARTER GEN. INOPERATIVE. (CAN) AFTER ATTEMPTING TO START RT ENGINE, A SMALL NOISE OCCURRED BUT THE ENGINE DID NOT ROTATE, MUCH LESS START. - [SDR CA140527010](https://openairdocs.org/sdr/CA140527010), May 26, 2014: THROTTLE CABLE. DAMAGED. (CAN) PILOT WAS STARTING ACFT. WHEN HE GOT TO 62 N1 HE LT OFF OF THE START SWITCH ACFT IMMEDIATELY WENT TO 110 NR. TORQUE WENT AS HIGH AS 90 PERCENT. HE CLOSED - [SDR CA140522006](https://openairdocs.org/sdr/CA140522006), May 12, 2014: INDICATOR. STUCK. (CAN) TORQUE INDICATOR WOULD NOT INDICATE DUE TO NEEDLE "FROZEN" NOT MOVING. REMOVED SN 302 AND INSTALLED PN 206-075-185-003, TSI 0.0. - [SDR CA140522010](https://openairdocs.org/sdr/CA140522010), May 12, 2014: BUSHING. WORN. (CAN) TORQUE TRANSMISSION RESTRAINT DUE TO EXCESSIVE PLAY. REMOVED LT STOP ASSY DUE TO WORN BUSHINGS. INSTALLED NEW & SERVICEABLE TSI 0.0 PARTS IN COMPLIANCE WI - [SDR CA130724008](https://openairdocs.org/sdr/CA130724008), Jun 27, 2013: CIRCUIT BREAKER. TRIPPED. (CAN) DURING FLIGHT, THE PILOT SAW THAT THE NR 1 ENGINE OIL TEMP REACHED 119 DEGREES C FOR 2 MINUTES AND THAT THE CB1, CB17 POPPED OUT. IT`S ALWAYS HAPPENED WHE - [SDR CA130506008](https://openairdocs.org/sdr/CA130506008), May 2, 2013: GOVERNOR. MALFUNCTIONED. (CAN) DURING TAKEOFF, PILOT REPORTS N2 DROOP FROM 100 PERCENT TO 98 PERCENT. PILOT TRIED TO ACTUATE THE GOVERNOR BACK TO 100 PERCENT, AT THAT POINT IT DROPPED F - [SDR CA130416018](https://openairdocs.org/sdr/CA130416018), Apr 4, 2013: SWITCH. LEAKING. (CAN) FUEL LEAKING FROM FUEL FLOW SWITCH. REPLACED WITH SERVICEABLE SWITCH. - [SDR CA121011009](https://openairdocs.org/sdr/CA121011009), Oct 7, 2012: FILTER. BROKEN. (CAN) DURING START CYCLE, PILOT HEARD A BANG. HE ABORTED THE START AND WENT TO LOOK FOR THE SOURCE OF THE NOISE. UPON OPENING ENGINE COWLING HE SAW FUEL POURING - [SDR 2012FA0000218](https://openairdocs.org/sdr/2012FA0000218), Mar 7, 2012: INDICATOR. FAILED. DURING ROUTINE INSPECTION, DISCOVERED THAT AFTER MAIN ROTOR TRANSMISSION OIL WAS DRAINED, OIL LEVEL INDICATED FULL. OIL LEVEL SIGHT GLASS REMOVED. INSPECTION OF - [SDR CA120113009](https://openairdocs.org/sdr/CA120113009), Jan 11, 2012: BLADE. DELAMINATED. (CAN) BEST DESCRIBE THIS DEFECT AS A CONVEX BUBBLE DELAMINATION IN THE SKIN OF THE BLADE. DEFECT IS FOUND ON BOTH TOP AND BOTTOM OF BLADE, SAME SIZE AND SHAPE F - [SDR CA110718013](https://openairdocs.org/sdr/CA110718013), Jun 30, 2011: FAN. FAILED. DURING A FLIGHT THE PILOT REPORT SHUTDOWN NR 2 ENGINE BECAUSE OF OIL OVERTEMP UP TO 150 DEGREES AND ABOVE 120 DEGREES FOR 2 MIN. LANDED SAFELY. CAUSE WAS COOLER - [SDR CA110321007](https://openairdocs.org/sdr/CA110321007), Mar 18, 2011: BEARING. BROKEN. (CAN) ENG CHIP LIGHT EXPERIENCED. SERVICEABILITY CHECK CARRIED OUT. ENG CHIP LIGHT EXPERIENCED. GEARBOX REMOVED, DISCOVERED OUTER RACER OF NR 4 BEARING BROKEN. - [SDR CA101202014](https://openairdocs.org/sdr/CA101202014), Nov 28, 2010: DISC PACK. CRACKED. UPON INSP OF THE TAIL ROTOR DRIVESHAFT COUPLINGS, 1 DISK IN THE COUPLING DISK PACK, 2ND FROM THE FRONT, WAS FOUND TO HAVE CRACKED. CRACK DISCOVERED AT AFT 2094. - [SDR CA101116010](https://openairdocs.org/sdr/CA101116010), Nov 7, 2010: PUMP. DAMAGED. EXCESSIVE NOISE ON START ATTEMPT. REMOVED FUEL PUMP T 1061006 + TRACED NOISE TO FUEL PUMP. SEND TO O/H SHOP. INSTALLED ANOTHER TSO 0.0 UNIT NDF. - [SDR CA101115021](https://openairdocs.org/sdr/CA101115021), Nov 5, 2010: SOLENOID. BURNED. (CAN) BLEW CIRCUIT BREAKER. ON INSPECTION, SOLENOID WAS BURNT. SENT TO O/H SHOP. INSTALLED TSO 0.0 UNIT. - [SDR CA100927010](https://openairdocs.org/sdr/CA100927010), Sep 15, 2010: BEARING. SPALLED. TRANSMISSION CHIP LIGHT CAUSED BY STEADY BEARING ON INPUT PINION. - [SDR CA100927011](https://openairdocs.org/sdr/CA100927011), Jul 23, 2010: BEARING. SPALLED. ENGINE CHIP LIGHT CAUSED BY 2.5 BEARING. - [SDR CA100430004](https://openairdocs.org/sdr/CA100430004), Apr 26, 2010: CLUTCH. SEIZED. (CAN) UNUSUAL NOISE DETECTED BY THE PILOT ON SHUT DOWN. FURTHER INVESTIGATION REVEALS SEIZED FREEWHEEL. FREE WHEEL REMOVED AND SENT TO INVESTIGATION TO SKYLINE - [SDR CA091013003](https://openairdocs.org/sdr/CA091013003), Oct 10, 2009: BLADE. DELAMINATED. (CAN) DURING DAILY INSP PILOT NOTICED THE OTBD T/E SKIN WAS DELAMINATED 6 INCHES FROM THE TIP ON TAIL ROTOR BLADE PN 206-016-201-131, SN CS-12194 BLADE HAS 120. - [SDR CA091008004](https://openairdocs.org/sdr/CA091008004), Oct 8, 2009: BEARING. WORN. (CAN) ENGINE CHIP LIGHT FOUND PROBLEM WITH THE BALL BEARING ON THE POWER TAKEOFF OUTPUT SHAFT. - [SDR CA090902006](https://openairdocs.org/sdr/CA090902006), Aug 21, 2009: BEARING. SPALLED. ENG CHIP LIGHT PROBLEM FOUND WITH THE BALL BRG ON THE PWR TAKEOFF OUTPUT SHAFT. - [SDR CA090902007](https://openairdocs.org/sdr/CA090902007), Aug 21, 2009: BEARING. SPALLED. ENG CHIP LIGHT, FOUND PROBLEM WITH THE PWR TAKEOFF OUTPUT SHAFT BEARING, INNER AND OUTER RACE WORN. - [SDR CA091103006](https://openairdocs.org/sdr/CA091103006), Jun 9, 2009: BEARING. FAILED. (CAN) ENG WAS REMOVED AFTER METAL CONTAMINATION AND SENT TO A REPAIR FACILITY. THE 2.5 BEARING WAS FOUND TO HAVE SPALLED ROLLERS AND RACE AND WAS MISSING A ROLL - [SDR CA090518001](https://openairdocs.org/sdr/CA090518001), May 15, 2009: BEARING. CORRODED. (CAN) RECEIVED MAIN ROTOR HUB FOR 1200 HOUR INTERIM INSP. WHEN DISASSEMBLED FOUND BOTH OTBD EXCLUDERS IN GRIP ASSEMBLIES WERE NO LONGER RETAINING LUBRICANT AND - [SDR CA090505008](https://openairdocs.org/sdr/CA090505008), Apr 15, 2009: CHIP DETECTOR. CONTAMINATED. (CAN) AFTER RECEIVING A COMPLETE TRANSMISSION ASSY FROM OVERHAUL FROM THE ORIGINAL EQUIPMENT VENDOR, A RECEIVING INSP WAS CARRIED OUT. THIS INSP INCLUDED VISUAL - [SDR CA090512002](https://openairdocs.org/sdr/CA090512002), Apr 11, 2009: BEARING. WORN. (CAN) PILOT HAD A ENGINE CHIP LIGHT INDICATION, ENGINE WAS REPLACED, INSP REVEALED TURBINE NR 5 BEARING WAS WORN AND SOME BALLS MISSING. - [SDR CA090401009](https://openairdocs.org/sdr/CA090401009), Mar 31, 2009: BUSHING. CRACKED. ROUTINE INSPECTION DISCOVERED A CRACK BETWEEN THE THROTTLE ARM BUSHING AND ROLL PIN ACCESS HOLE. COLLECTIVE ELBOW FOUND TO BE CORRECTLY INSTALLED AND NO OTHER D - [SDR CA090217004](https://openairdocs.org/sdr/CA090217004), Feb 12, 2009: PUMP. FAILED. (CAN) DURING NORMAL FLAT AND LEVEL CRUISE FLIGHT AT APPROX. 4000` ASL THE PILOT INITIATED A GENTLE RT TURN. UPON MOVING THE CYCLIC CONTROL THE PILOT NOTED ROUGH - [SDR CA081223003](https://openairdocs.org/sdr/CA081223003), Dec 9, 2008: RELEASE CABLE. SEPARATED. (CAN) PILOT REPORTED UN-COMMANDED HOOK RELEASE (LOSS OF LEAD) UPON INSPECTION FOUND FAULTY MANUAL RELEASE CABLE WHEN HOOK PULLED TO FAR END OF SWAGED END SEPARA - [SDR CA080923004](https://openairdocs.org/sdr/CA080923004), Sep 22, 2008: OIL SYSTEM. OVERTEMP. (CAN) ENGINE OIL TEMPERATURE INCREASED TO 100 DEG. C. - [SDR CA080813002](https://openairdocs.org/sdr/CA080813002), Aug 13, 2008: PITCH HORN. LOOSE. (CAN) THE STUD WHICH HOLDS THE PITCH LINKS ONTO THE PITCH HORN CAME LOOSE. THIS CAUSED A VIBRATION FELT IN THE PEDALS. THE TAILROTOR HUB WAS 2400 HOURS TSO AND - [SDR CA080715007](https://openairdocs.org/sdr/CA080715007), Jul 15, 2008: PITCH HORN. DAMAGED. (CAN) THE PITCH HORN STUD FAILED WHILE INSTALLING A NUT P/N MS14145L5. A "CLICKER-TYPE" TORQUE WRENCH SET TO 60 INCH/LBS WAS USED TO INSTALL THE NUT. THE REQUIR - [SDR 2007F00067](https://openairdocs.org/sdr/2007F00067), Nov 6, 2007: SHAFT. SHEARED. ENGINE EXPERIENCED AN N2 OVERSPEED IN FLIGHT. PILOT REGAINED CONTROL WITH THROTTLE AND LANDED AIRCRAFT WITHOUT FURTHER INCIDENT. REMOVAL OF GOVERNOR FOUND INPUT - [SDR CA070814002](https://openairdocs.org/sdr/CA070814002), Jul 10, 2007: BLADE. DAMAGED. (CAN) UPON LANDING IN A BRUSH AREA, THE PILOT LOWERED THE COLLECTIVE, WHICH IN TURN RAISED (2) TREES THAT WERE SITUATED ON THE LEFT AND THEN HIT THE ROTOR DISK. - [SDR CA070518001](https://openairdocs.org/sdr/CA070518001), May 14, 2007: LEVER. BROKEN. (CAN) PART BROKE IN (2) PIECES JUST ABOVE ATTACHMENT POINT DURING ENGINE PRE-START CHECK PROCEDURES. (TC NR 20070518001) - [SDR CA061128001](https://openairdocs.org/sdr/CA061128001), Nov 24, 2006: LINE. LEAKING. (CAN) DURING A SCHEDULED FLIGHT, FUEL FUMES WERE DETECTED IN REAR CABIN AREA. A/C RETURNED TO BASE WITH NO PROBLEMS NOTED. A/C INSPECTED AND FWD FUEL TANK VENT - [SDR CA061219004](https://openairdocs.org/sdr/CA061219004), Nov 21, 2006: GOVERNOR. ERRATIC. (CAN) HIGH TIME GOVERNOR TSO 1889.2, REMOVED FOR O/H DUE TO ERRATIC RPM REPLACED WITH NEW GOVERNOR PN 23076061 SN HR47346 TSN 0:0 (TC NR 20061219004) - [SDR CA061219005](https://openairdocs.org/sdr/CA061219005), Nov 21, 2006: ACTUATOR. FAILED. (CAN) REMOVED LINEAR ACTUATOR PN 7185-13 SN 0296A DUE TO INTERNAL LOCKING CLIP FALLING OFF. INSTALLED SERVICEABLE USED LINEAR ACTUATOR PN 206-062-721-003 SN 118 - [SDR CA061109006](https://openairdocs.org/sdr/CA061109006), Nov 9, 2006: SKIN. CRACKED. (CAN) CRACK FOUND IN SKIN UNDER FWD BEARING OIL COOLER SUPPORT RT STA 192.00 BUTT 4.0. REPAIR WAS MADE IAW BHT-206-SRM-4-2 (TC NR 20061109006) - [SDR CA061019004](https://openairdocs.org/sdr/CA061019004), Oct 3, 2006: INDICATOR. MALFUNCTIONED. (CAN) FUEL PRESSURE OVER-READING. PEGS AT 30 PSI WITH BOTH PUMPS AND GENERATOR ON. REMOVED FOR REPAIR AT INSTRUMENT SHOP. (TC NR 20061019004) - [SDR CA061019005](https://openairdocs.org/sdr/CA061019005), Oct 3, 2006: INDICATOR. LEAKING. (CAN) OIL IN GAUGE GLASS. REMOVED FOR REPAIR AT INSTRUMENT SHOP. (TC NR 20061019005) All 111: https://openairdocs.org/engine/allison-250-c20r/reports.md ## STCs that may be installed (OpenAirDocs) (5) 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 - [STC SQ00338AT](https://openairdocs.org/stc/SQ00338AT): Unison igniter leads, P/N9048222-101, 102, 103, 104, 105, 106. 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.