# Lycoming IO-720-D1C - Type: Engine model (FAA registry) - Registry code: 41958 - Manufacturer (registry): LYCOMING - Model: IO-720-D1C - Engine type: Reciprocating - Power: 400 hp - Data sheet: [TCDS 1E15](https://openairdocs.org/tcds/1E15) (OpenAirDocs) - Holder: Textron Lycoming Subsidiary of Textron Inc. - Installed in: 0 registered aircraft - Page: https://openairdocs.org/engine/lycoming-io-720-d1c 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 2026-04-11](https://openairdocs.org/ad/2026-04-11): Engine (Reciprocating) · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 605 more. Effective Apr 8, 2026 - [AD 2017-16-11](https://openairdocs.org/ad/2017-16-11): Reciprocating Engine Power Section · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-360-B1G6 and 93 more. Effective Aug 15, 2017 - [AD 2015-19-07](https://openairdocs.org/ad/2015-19-07): Fuel injector fuel lines · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1B and 187 more. Effective Nov 3, 2015 - [AD 2012-19-01](https://openairdocs.org/ad/2012-19-01): Crankshafts · Lycoming Engines AEIO-360-A1A, AEIO-360-A1B, AEIO-360-A1B6 and 321 more. Effective Oct 24, 2012 - [AD 2010-07-08](https://openairdocs.org/ad/2010-07-08): Turbochargers · Kelly Aerospace Energy Systems HIO-360-E1AD, HIO-360-E1BD, HIO-360-F1AD and 137 more. Effective Apr 19, 2010 - [AD 2004-10-14](https://openairdocs.org/ad/2004-10-14): Crankshaft gear · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 642 more. Effective Jun 25, 2004 - [AD 2003-14-03](https://openairdocs.org/ad/2003-14-03): Rotary fuel pumps · Lycoming Engines AEIO-540-D4A5, AEIO-540-D4B5, AEIO-540-D4C5 and 262 more. Effective Aug 14, 2003 - [AD 98-17-11](https://openairdocs.org/ad/98-17-11): Crankshafts · Continental Motors A-65-3, A-65-8, A75-8 and 90 more. Effective Oct 19, 1998 - [AD 97-15-11](https://openairdocs.org/ad/97-15-11): Cylinder kits · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 538 more. Effective Aug 12, 1997 - [AD 92-12-05](https://openairdocs.org/ad/92-12-05): Piston Pins · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 532 more. Effective Jul 10, 1992 Historical (superseded or no longer in force): - [AD 2011-26-04](https://openairdocs.org/ad/2011-26-04) (historical): Externally mounted fuel injector fuel lines · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1B and 186 more. Effective Jan 25, 2012 - [AD 2011-15-10](https://openairdocs.org/ad/2011-15-10) (historical): Fuel servos · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 256 more. Effective Aug 16, 2011 - [AD 2008-14-07](https://openairdocs.org/ad/2008-14-07) (historical): Externally mounted fuel injector fuel lines · Textron Lycoming, AVCO AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1B and 185 more. Effective Aug 14, 2008 - [AD 2006-20-09](https://openairdocs.org/ad/2006-20-09) (historical): Certain crankshafts replacing · Lycoming Engines AEIO-360-A1B6, AEIO-360-A1E6, AEIO-540-D4A5 and 82 more. Effective Nov 3, 2006 - [AD 2002-26-01](https://openairdocs.org/ad/2002-26-01) (historical): Fuel injector fuel lines · Textron Lycoming, AVCO IGO-480-A1B6, IGO-540-B1A, IGO-540-B1C and 178 more. Effective Jan 31, 2003 - [AD 98-18-12](https://openairdocs.org/ad/98-18-12) (historical): Fuel Pump · Textron Lycoming, AVCO AEIO-540-D4A5, AEIO-540-D4B5, AEIO-540-D4C5 and 249 more. Effective Sep 28, 1998 ## Information bulletins (advisory) (1) - [SAIB NE-08-32R1](https://openairdocs.org/saib/NE-08-32R1): Propeller Governor Idler Gear Shaft Set Screw. Issued May 13, 2016 ## Registered aircraft None registered with this engine model now. ## 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 (9) As reported by operators and repair stations, by the model named in the report. - [SDR CA140515006](https://openairdocs.org/sdr/CA140515006), May 15, 2014: BOOT. UNSECURE. (CAN) LT AND RT CONTROL BOOTS FOR AILERON CONTROL RODS CAME LOOSE, UNGLUED IN WING CENTER SECTION. - [SDR AUS20031000](https://openairdocs.org/sdr/AUS20031000), Sep 30, 2003: STRUCTURE. CRACKED. (AUS) AIRCRAFT STRUCTURE CRACKED IN TOP RT ENGINE MOUNT ATTACHMENT AREA WHEN LOOKING FORWARD. FOUND DURING INSPECTION IAW AD/PA36/20AMDT1. - [SDR AG2R04230201](https://openairdocs.org/sdr/AG2R04230201), Apr 23, 2002: BUSHING. FAILED. COUNTER WEIGHT BUSHINGS (PN LS73810) HAVE FAILED AT 2 TO 250 HOURS. IT APPEARS THAT THE MATERIAL MAY BE TOO SOFT. BUSHINGS WERE REMOVED BY OPERATOR AND SENT BAC - [SDR AUS20020033](https://openairdocs.org/sdr/AUS20020033), Jan 16, 2002: FITTING. CRACKED. (AUS) RT FRONT SPAR ATTACHMENT FITTING ON FUSELAGE LOCATED AT RT STN 124.250 CRACKED IN REAR LAMINATE. CRACK LENGTH 10MM (0.39IN). - [SDR AUS20011082](https://openairdocs.org/sdr/AUS20011082), Oct 10, 2001: CRANKSHAFT. BROKEN. (AUS) ENGINE CRANKSHAFT BROKEN IN WEB LOCATED FORWARD OF MAIN BEARING JOURNAL BETWEEN NO5/NO6 AND NO7/NO8 CYLINDER BANKS. ONE CONNECTING ROD CRACKED. - [SDR AU981397](https://openairdocs.org/sdr/AU981397), Oct 16, 1998: SPAR. CORRODED. (AUS) FIN STRUCTURE EXTENSIVELY CORRODED. FORWARD ATTACHMENT POINT, REAR SPAR AND LOWER RIB AS WELL AS THE INNER SKIN AND UPPER FIN STRUCTURE CORRODED. - [SDR CA970423016](https://openairdocs.org/sdr/CA970423016), Apr 18, 1997: TAPPET BODY. SPALLED. (CAN) ENGINE WAS REMOVED DUE TO METAL CONTAMINATION. #1 EXHAUST LOBE WAS WORN. TAPPET BODY WAS SPALLED, PITTED AND DEFORMED. CAMSHAFT LOBE WAS PITTED AND WORN D - [SDR AU970939](https://openairdocs.org/sdr/AU970939), Mar 19, 1997: SPAR. CRACKED. (AUS) RUDDER SPAR CRACKED ON BOTH SIDES OF HINGE - HINGE BRACKET PNO76847-02 ALSO CRACKED - [SDR AU970933](https://openairdocs.org/sdr/AU970933), Jan 1, 1997: SPAR. CRACKED. (AUS) FIN REAR SPAR CRACKED ALLOWING TOP AND MIDDLE RUDDER ATTACHMENT BRACKETS TO SEPARATE ## STCs that may be installed (OpenAirDocs) (23) 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 SE00825WI](https://openairdocs.org/stc/SE00825WI): Installation of Specialty Products Spin-on oil filter on Lycoming Engines. B & C Specialty Products Inc - [STC SE02352CH](https://openairdocs.org/stc/SE02352CH): Installation of Challenger cleanable oil filter assembly. Challenger Aviation Products Inc - [STC SE00939WI](https://openairdocs.org/stc/SE00939WI): Installation of B&C Specialty Products Model BC 315-( ) Starter on Lycoming engines. B & C Specialty Products Inc - [STC SE01966WI](https://openairdocs.org/stc/SE01966WI): Use of GAMI G100UL High Octane Unleaded Avgas in spark ignition piston aircraft engines. General Aviation Modifications Inc - [STC SE8628SW](https://openairdocs.org/stc/SE8628SW): Installation of oil nozzles for lubrication of cam and filters. Cygnet Aerospace Corp - [STC SE09445SC](https://openairdocs.org/stc/SE09445SC): Installation of fuel injector nozzles. General Aviation Modifications Inc. Lists IO-720 Series - [STC SE4408SW](https://openairdocs.org/stc/SE4408SW): Miscellaneous engine cylinder replacement parts. Continental Motors, Inc. Lists IO-720 Series - [STC SE7506SW](https://openairdocs.org/stc/SE7506SW): Installation of any or all parts listed on Airmotive Engineering Drawing List No. 852-1, Rev. 1, dated 10/4/88, or later FFA approved revision. Continental Motors, Inc. Lists IO-720 Series - [STC SE7670SW](https://openairdocs.org/stc/SE7670SW): Installation of parts listed on Drawing List No. 8810-3, Rev 6. Continental Motors, Inc. Lists IO-720 Series - [STC SE8776SW](https://openairdocs.org/stc/SE8776SW): Installation of coated cylinders and piston rings. Continental Motors, Inc. Lists IO-720 Series - [STC SE00226NY](https://openairdocs.org/stc/SE00226NY): Replacement of Lycoming starter with SKY-TEC 24-volt starter Models 149-24HT and 122-24HT. Approval limited to 24-volt DC source available to the starter. Hartzell Engine Technologies, LLC - [STC SE2902NM](https://openairdocs.org/stc/SE2902NM): Lycoming valve cover gasket. Real Gaskets Tennessee - [STC SE7582SW](https://openairdocs.org/stc/SE7582SW): Grinding of high compression NITRIDED Cylinders to .010 oversize, as an alternative to chrome plating or rebarreling, and the installation of SL10207 P10 Piston, SL74241 P10 Top and second compression ring, and SL 73857 P10 oil control ring. Superior Air Parts, Inc - [STC SE01930NY](https://openairdocs.org/stc/SE01930NY): Installation of Casper Labs 90 degree oil filter housing adapter. Casper Labs Inc - [STC SE1779NM](https://openairdocs.org/stc/SE1779NM): Installation of Precise Flight, Inc. Standby Vacuum System SVS III. Precise Flight Inc - [STC SE09492SC](https://openairdocs.org/stc/SE09492SC): Installation and usage of Exxon 20W50 multigrade aircraft engine oil conforming to Exxon Oil formulation WS-3013. Exxon Company USA. Lists IO-720 Series - [STC SE00350SE](https://openairdocs.org/stc/SE00350SE): Installation of sump mounted chip detector. Aviation Development Corporation - [STC SE00299WI](https://openairdocs.org/stc/SE00299WI): Installation of B & C Specialty Products lightweight (10.2 pounds) engine starter P/N BC315-100-1(12 volts) or P/N BC 315-100-3(24 volts). Bainbridge William C III - [STC SE8023SW](https://openairdocs.org/stc/SE8023SW): Installation and usage of AEROSHELL. Shell Development Co. Lists IO-720 Series - [STC SE452NE](https://openairdocs.org/stc/SE452NE): Installation and usage of 'Mobil AV 1' aviation oil. Mobil Research & Development Corp. Lists IO-720 Series - [STC SE5879SW](https://openairdocs.org/stc/SE5879SW): Use of Phillips X/C II 20W-50 and25W-60 oil (OSS 55875) in all Avco reciprocating aircraft engines from 65 to 450 BHP. Phillips Petroleum Co. Lists IO-720 Series - [STC SE5924SW](https://openairdocs.org/stc/SE5924SW): Installation of stainless steel replacement exhaust studs on AVCO engines. Perrigo & Steele Aircraft Engr Company. Lists IO-720 Series - [STC SE128NE](https://openairdocs.org/stc/SE128NE): Use of AMS/OIL 15W 50 synthetic piston aircraft oil in Avco engines. AMS/OIL. Lists IO-720 Series --- 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.