# Continental TSIO-520-BB

- Type: Engine model (FAA registry)
- Registry code: 17250
- Manufacturer (registry): CONT MOTOR
- Model: TSIO-520-BB
- Engine type: Reciprocating
- Power: 285 hp
- Data sheet: [TCDS E8CE](https://openairdocs.org/tcds/E8CE) (OpenAirDocs)
- Holder: Continental Aerospace Technologies, Inc.
- Installed in: 1 registered aircraft
- Page: https://openairdocs.org/engine/continental-tsio-520-bb

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 2023-17-04](https://openairdocs.org/ad/2023-17-04): Reciprocating Engine Oil System · F & M Enterprises' Model C6LC, C6LC-S or C6LC-L oil filter… (Stratus Tool Technologies STC SE09356SC or 2 others). Effective Oct 26, 2023
- [AD 2023-05-16](https://openairdocs.org/ad/2023-05-16): Reciprocating Engine Power Section · Continental Aerospace Technologies GTSIO-520-C, GTSIO-520-D, GTSIO-520-H and 147 more. Effective Mar 15, 2023
- [AD 2023-02-12](https://openairdocs.org/ad/2023-02-12): Engine Air Intake System · Continental Aerospace Technologies GTSIO-520-C, GTSIO-520-D, GTSIO-520-E and 127 more. Effective Feb 17, 2023
- [AD 2022-16-03](https://openairdocs.org/ad/2022-16-03): Engine (RECIPROCATING) · Continental Aerospace Technologies GTSIO-520-C, GTSIO-520-D, GTSIO-520-F and 236 more. Effective Aug 15, 2022
- [AD 2016-16-12](https://openairdocs.org/ad/2016-16-12): Cylinder assemblies · Continental Motors LTSIO-520-AE, TSIO-520-A, TSIO-520-AE and 89 more. Effective Sep 15, 2016
- [AD 2014-05-29](https://openairdocs.org/ad/2014-05-29): SAP replacement parts manufacturer approval (PMA) investment cast cylinder assemblies · Continental Motors TSIO-520-A, TSIO-520-AE, TSIO-520-AF and 55 more. Effective Apr 25, 2014
- [AD 2012-10-13](https://openairdocs.org/ad/2012-10-13): Starter adapters · Continental Motors IO-550-N, TSIO-520-B, TSIO-520-BB and 14 more. Effective Jun 8, 2012
- [AD 2012-03-06](https://openairdocs.org/ad/2012-03-06): Fuel servo diaphragm · Continental Motors 6-260-A, 6-285-A, 6-285-B and 482 more. Effective Feb 24, 2012
- [AD 2010-11-04](https://openairdocs.org/ad/2010-11-04): Hydraulic lifters · Continental Motors FSO-470-A, GIO-470-A, GTSIO-520-C and 190 more. Effective Jun 16, 2010
- [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 2009-19-07](https://openairdocs.org/ad/2009-19-07): EQ3 cylinders · Continental Motors IO-470-C, IO-470-D, IO-470-E and 72 more. Effective Oct 7, 2009
- [AD 2007-04-19 R1](https://openairdocs.org/ad/2007-04-19-R1): SAP cylinder assemblies · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 314 more. Effective May 7, 2007
- [AD 2004-08-10](https://openairdocs.org/ad/2004-08-10): Serial-numbered (SN) cylinders · Modify Teledyne Continental TSIO-520-NB engine (RAM Aircraft Limited Partnership STC SE09104SC or 4 others). Effective May 5, 2004
- [AD 2000-23-21](https://openairdocs.org/ad/2000-23-21): Crankshaft · Continental Motors IO-360-A, IO-360-AB, IO-360-B and 164 more. Effective Dec 12, 2000
- [AD 99-19-01](https://openairdocs.org/ad/99-19-01): No. 2 and No. 5 Crankshaft Inspections · Continental Motors GTSIO-520-C, GTSIO-520-D, GTSIO-520-E and 127 more. Effective Sep 30, 1999
- [AD 97-26-17](https://openairdocs.org/ad/97-26-17): Crankshaft · Continental Motors IO-360-A, IO-360-AB, IO-360-B and 90 more. Effective Jan 23, 1998
- [AD 96-12-22](https://openairdocs.org/ad/96-12-22): Full Flow Engine Oil Adapter · Bellanca CH-300 Pacemaker, 120, 140 and 361 more. Effective Jul 31, 1996
- [AD 93-16-15](https://openairdocs.org/ad/93-16-15): Fuel Pump Drive Shaft · Continental Motors IO-520-B, IO-520-BA, IO-520-BB and 27 more. Effective Dec 14, 1993
- [AD 93-08-17](https://openairdocs.org/ad/93-08-17): Oil Pick-Up Tube · Continental Motors IO-470-A, IO-470-C, IO-470-D and 104 more. Effective Aug 23, 1993
- [AD 93-10-02](https://openairdocs.org/ad/93-10-02): Missing Cylinder Valve Retainer Key · Continental Motors GTSIO-520-C, GTSIO-520-D, GTSIO-520-E and 180 more. Effective Aug 12, 1993
- [AD 91-19-03](https://openairdocs.org/ad/91-19-03): Oil Filter · Continental Motors 6-285-A, 6-285-B, 6-285-BA and 169 more. Effective Sep 29, 1991
- [AD 89-24-01 R1](https://openairdocs.org/ad/89-24-01-R1): Scavenge Oil Pump Gears · Continental Motors TSIO-520-B, TSIO-520-BB, TSIO-520-D and 11 more. Effective Aug 10, 1990
- [AD 88-03-06](https://openairdocs.org/ad/88-03-06): Oil Filter · Continental Motors GTSIO-520-C, GTSIO-520-D, GTSIO-520-E and 155 more. Effective Apr 15, 1988
- [AD 86-13-04 R3](https://openairdocs.org/ad/86-13-04-R3): Cylinder Assemblies · Continental Motors GTSIO-520-C, GTSIO-520-D, GTSIO-520-H and 44 more. Effective Feb 24, 1988
- [AD 81-24-06](https://openairdocs.org/ad/81-24-06): Engine Driven Fuel Pumps · Continental Motors GTSIO-520-C, GTSIO-520-D, GTSIO-520-E and 51 more. Effective Nov 23, 1981
- [AD 81-16-05](https://openairdocs.org/ad/81-16-05): Magnetos · Lycoming Engines AEIO-320-E1B, AEIO-320-E2B, AEIO-360-B1G6 and 234 more. Effective Aug 6, 1981
- [AD 80-01-04](https://openairdocs.org/ad/80-01-04): Cylinder Holddown Flange Assemblies · Continental Motors IO-520-A, IO-520-B, IO-520-BA and 44 more. Effective Jan 25, 1980
- [AD 79-05-09](https://openairdocs.org/ad/79-05-09): Oil Pump Assembly Or Oil Pressure Relief Valve Screw And/Or Plunger · Teledyne Continental Motors 6-285-CA, GTSIO-520-C, GTSIO-520-D and 60 more. Effective Mar 12, 1979
- [AD 98-01-08](https://openairdocs.org/ad/98-01-08): Exhaust Roller Rocker Arm · Roller rocker arm P/N PE 92I intake and PE92E exhaust (Performance Engineering STC SE8594SW)

Historical (superseded or no longer in force):

- [AD 2023-04-08](https://openairdocs.org/ad/2023-04-08) (historical): Reciprocating Engine Power Section · Continental Aerospace Technologies GTSIO-520-C, GTSIO-520-D, GTSIO-520-H and 141 more. Effective Feb 23, 2023
- [AD 2011-25-51](https://openairdocs.org/ad/2011-25-51) (historical): Starter Adapter Gear Shaft · Continental Motors IO-550-N, TSIO-520-B, TSIO-520-BB and 14 more. Effective Dec 28, 2011
- [AD 2009-24-52](https://openairdocs.org/ad/2009-24-52) (historical): Hydraulic lifters · Continental Motors FSO-470-A, GIO-470-A, GTSIO-520-C and 192 more
- [AD 2009-24-51](https://openairdocs.org/ad/2009-24-51) (historical): Hydraulic lifters · Teledyne Continental Motors FSO-470-A, GIO-470-A, GTSIO-520-C and 156 more
- [AD 2009-16-03](https://openairdocs.org/ad/2009-16-03) (historical): Cylinder assemblies · Continental Motors IO-520-A, IO-520-B, IO-520-BA and 55 more. Effective Sep 9, 2009
- [AD 2000-08-51](https://openairdocs.org/ad/2000-08-51) (historical): Crankshaft · Teledyne Continental Motors IO-360-A, IO-360-AB, IO-360-B and 158 more
- [AD 99-09-17](https://openairdocs.org/ad/99-09-17) (historical): Crankshaft · Teledyne Continental Motors IO-470-A, IO-470-C, IO-470-D and 114 more

## Information bulletins (advisory) (11)

- [SAIB NE-20-05](https://openairdocs.org/saib/NE-20-05): POWERPLANT - Engine Camshaft Gear Tooth Fracture. Issued Apr 6, 2020
- [SAIB NE-18-16](https://openairdocs.org/saib/NE-18-16): POWERPLANT  Alternator Drive Coupling. Issued Jun 20, 2018
- [SAIB NE-17-11](https://openairdocs.org/saib/NE-17-11): POWERPLANT  Engine damage as a result of kickback. Issued May 10, 2017
- [SAIB NE-16-13](https://openairdocs.org/saib/NE-16-13): Powerplant - Prohibited use of sealant. Issued Mar 8, 2016
- [SAIB NE-13-15](https://openairdocs.org/saib/NE-13-15): Engine Controls: Continental Motors, Inc. (CMI) Throttle and Mixture Control Levers. Issued Feb 8, 2013
- [SAIB NE-13-04](https://openairdocs.org/saib/NE-13-04): Continental Motors, Inc. (CMI) Connecting Rod Piston Pin Bushing Inspection. Issued Oct 31, 2012
- [SAIB NE-10-09](https://openairdocs.org/saib/NE-10-09): Reciprocating Engine Power Section: Hydraulic Valve Lifters. Issued Nov 20, 2009
- [SAIB NE-10-07](https://openairdocs.org/saib/NE-10-07): Reciprocating Engine Cylinder: Identification Information for Superior Air Parts, PMA Cylinder Heads for Teledyne Continental Motors (TCM) IO-520, TSIO-520,and IO-550 Series Engines.. Issued Nov 2, 2009
- [SAIB NE-09-08](https://openairdocs.org/saib/NE-09-08): Reciprocating Engine Cylinder Section. Issued Jan 30, 2009
- [SAIB NE-07-09R1](https://openairdocs.org/saib/NE-07-09R1): Periodic Inspections of ECi Cylinder Assemblies for Cracks in the Aluminum Head. Issued Mar 21, 2007
- [SAIB NE-02-41](https://openairdocs.org/saib/NE-02-41): . Issued Aug 8, 2002

## Registered aircraft (1)

- [N314HB](https://openairdocs.org/aircraft/N314HB): [Marc Inc](https://openairdocs.org/faa-owner/MARC%20INC), [Bolton, MS](https://openairdocs.org/faa-place/MS/Bolton), built 1979, S/N 310R1586

## NTSB investigations

None matched to aircraft with this engine model.

## FAA accident and incident reports (1)

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [Incident 20230102000169I](https://openairdocs.org/incident/20230102000169I), Jan 2, 2023: Cessna 310 (N2636P), Houma, LA, Minor damage. Pilot was making a landing at Houma terrebone airport, once the aircraft made contact with the runway the left tire blew out, from the picture it looks as if…

## Service difficulty reports (10)

As reported by operators and repair stations, by the model named in the report.

- [SDR 2022FA0000460](https://openairdocs.org/sdr/2022FA0000460), Jul 25, 2022: CYLINDER. BYPASSING. DURING A COMPRESSION TEST, THE #3 CYLINDER HAD LOWER COMPRESSION THAN THE MASTER ORIFICE NUMBER. THE LOWER PLUG WAS REMOVED AND IT WAS COVERED IN OIL. BORESCOPE
- [SDR 2022FA0000459](https://openairdocs.org/sdr/2022FA0000459), May 13, 2022: CRANKCASE. DESTROYED. AFTER CLIMBING TO 12000 FT FROM KCYS, THE AIRCRAFT TRANSITIONED TO CRUISE TO PREPARE FOR AERIAL SURVEY WORK. SHORTLY THEREAFTER, THE RE HAD A VIBRATION, POWER L
- [SDR 2012F00151](https://openairdocs.org/sdr/2012F00151), Aug 16, 2012: EXHAUST PIPE. CRACKED. REMOVED RT ENGINE FOR O/H AT REQUEST OF OPERATOR. FOUND EXHAUST OVERBOARD PIPE, CRACKED APPROX 80 PERCENT AROUND THE CIRCUMFERENCE OF THE PIPE. FOUND CORRODED R
- [SDR 2012F00152](https://openairdocs.org/sdr/2012F00152), Aug 16, 2012: BEAM. PERFORATED. REMOVED LEFT EXHAUST SYS FOR OVERHAUL AT REQUEST OF OPERATOR. FOUND MISSING & CORRODED RIVETS ON FIREWALL. SINGLE PIECE V-BAND CLAMPS WERE DISCOLORED CONSISTENT
- [SDR 2009F00137](https://openairdocs.org/sdr/2009F00137), Aug 12, 2009: CIRCUIT BREAKER. FAILED. CIRCUIT BREAKER FAILED INTERNALLY. WOULD NOT ALLOW POWER TO EXIT.
- [SDR 2007FA0000105](https://openairdocs.org/sdr/2007FA0000105), Feb 2, 2007: SPAR CAP. CORRODED. LT TOP WING SPAR CAPS AND TOP SKINS SEVERELY CORRODED IN AREA OF FACTORY NACELLE FUEL BLADDERS. LT-PN 5122031-1.
- [SDR 2006FA0000385](https://openairdocs.org/sdr/2006FA0000385), Mar 31, 2006: CYLINDER HEAD. SEPARATED. DURING FLIGHT, VIBRATION WAS NOTED ON RT ENGINE. INSPECTED ENGINE AND FOUND NR 6 CYLINDER SEPARATED WHERE BARREL MEETS HEAD. PROBABLE CAUSE: UNKNOWN. RECOMMENDA
- [SDR 2003FA0000966](https://openairdocs.org/sdr/2003FA0000966), Sep 10, 2003: ROD BOLT. DAMAGED. INSTALLED (1) NEW ROD BOLT, SA 629340 LOT NR 578901, ALONG WITH NEW NUT NR SA 628109. NUT WOULD NOT REACH SPEC. TORQUE. NUT WAS REMOVED TO REVEAL THREADS, DAMAG
- [SDR CA960418201](https://openairdocs.org/sdr/CA960418201), Apr 2, 1996: MOUNTING PAD. MISMACHINED. (CAN)MOUNTING HOLE AND PAD FOR ALTERNATOR MACHINED APPROXIMATELY .080 INCH TOO FAR FORWARD CAUSING ALTERNATOR DRIVE GEAR NOT MESHING PROPERLY.
- [SDR 95ZZZX2114](https://openairdocs.org/sdr/95ZZZX2114), Apr 4, 1995: TURBOCHARGER. FAILED. AIRCRAFT EXPERIENCED LOSS OF POWER ON RIGHT ENGINE DURING FLIGHT. THE ENGINE WAS SHUT DOWN AND MADE AN EMERGENCY LANDING. INVESTIGATION REVEALED THE TURBOCHARGE

## STCs that may be installed (OpenAirDocs) (52, first 50)

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 SE5583SW](https://openairdocs.org/stc/SE5583SW): Installation of fuel flow transducers (true-flow totalizer). Alcor LLC. Lists TSIO-520 Series
- [STC SE04349CH](https://openairdocs.org/stc/SE04349CH): Installation of SureFly electronic ignition. SureFly Partners Ltd
- [STC SE02352CH](https://openairdocs.org/stc/SE02352CH): Installation of Challenger cleanable oil filter assembly. Challenger Aviation Products Inc
- [STC SE03309CH](https://openairdocs.org/stc/SE03309CH): Installation of Engine Preheat Kit, p/n TSP6CYL-2927-115 for 115 volt application. Hartzell Propeller Inc
- [STC SE04577CH](https://openairdocs.org/stc/SE04577CH): Install an electronic engine ignition system. Electroair Acquisition Corp
- [STC SE09356SC](https://openairdocs.org/stc/SE09356SC): Install F & M Enterprises' Model C6LC, C6LC-S or C6LC-L oil filter adapter for a spin-on oil filter. Stratus Tool Technologies LLC
- [STC SE70RM](https://openairdocs.org/stc/SE70RM): Installation of compressor bracket. Air Comm Corporation
- [STC SE09637SC](https://openairdocs.org/stc/SE09637SC): Remove existing rocker arm assemblies and install modify rocker arm assemblies. General Aviation Modifications Inc
- [STC SE1186SW](https://openairdocs.org/stc/SE1186SW): Regrooving of pistons P/N 631475 or P/N 632585. Continental Motors, Inc
- [STC SE2340SW](https://openairdocs.org/stc/SE2340SW): Installation of modified cylinder assemblies, barrels, piston, and repaired crankcases. Continental Motors, Inc
- [STC SE5820SW](https://openairdocs.org/stc/SE5820SW): Installation of Airmotive exhaust valve, P/N AEC-637781. Continental Motors, Inc. Lists TSIO-520 Series
- [STC SE8776SW](https://openairdocs.org/stc/SE8776SW): Installation of coated cylinders and piston rings. Continental Motors, Inc. Lists TSIO-520 Series
- [STC SE09280SC-D](https://openairdocs.org/stc/SE09280SC-D): Modify engine in accordance with RAM Aircraft Corporation Drawing No. 1888. RAM Aircraft Limited Partnership
- [STC SE09281SC-D](https://openairdocs.org/stc/SE09281SC-D): Modify engine in accordance with RAM Aircraft Corporation Drawing Number 1891. RAM Aircraft Limited Partnership
- [STC SE3632SW-D](https://openairdocs.org/stc/SE3632SW-D): Installation of induction hose clamps. RAM Aircraft Limited Partnership
- [STC SE09282SC-D](https://openairdocs.org/stc/SE09282SC-D): Modify engine in accordance with RAM Aircraft Corporation Drawing Number 1892. RAM Aircraft Limited Partnership
- [STC SE09653SC-D](https://openairdocs.org/stc/SE09653SC-D): Installation of RAM Induction Equalized Fuel Nozzle Set. RAM Aircraft Limited Partnership
- [STC SE3631SW-D](https://openairdocs.org/stc/SE3631SW-D): Cylinder modifications. RAM Aircraft Limited Partnership
- [STC SE5726SW-D](https://openairdocs.org/stc/SE5726SW-D): Installation of Floscan - 20lb or - 203b fuel flow transducers. RAM Aircraft Limited Partnership
- [STC SE09846SC](https://openairdocs.org/stc/SE09846SC): Installation of S539800M30 starter adapter springs. Aircraft Specialties Services Inc
- [STC SE444GL](https://openairdocs.org/stc/SE444GL): Incorporation of a fuel flow transducer. Shadin Avionics
- [STC SE630SW](https://openairdocs.org/stc/SE630SW): Engine modifications. RAM Aircraft Limited Partnership
- [STC SE4651SW](https://openairdocs.org/stc/SE4651SW): Installation of Slick pressurized magnetos. Also eligible on Teledyne Continental TSIO-520-NB engines modified per STC SE4327SW. RAM Aircraft Limited Partnership
- [STC SE1780NM](https://openairdocs.org/stc/SE1780NM): Installation of Precise Flight standby vacuum system (SVS III). Precise Flight Inc
- [STC SE5726SW](https://openairdocs.org/stc/SE5726SW): Installation of Floscan -201b or -203b fuel flow transducers. RAM Aircraft Limited Partnership
- [STC SE5743NM](https://openairdocs.org/stc/SE5743NM): Intallation of adapter for externally mounted oil filter. Aviation Development Corporation
- [STC SE09261SC](https://openairdocs.org/stc/SE09261SC): Modify engine to increase power output rating from 310 hp to 335 hp, install Garrett/AlliedSignal TA-81 turbocharger, RAM intercooler, RAM economy camshaft, RAM oil pump pickup tube, RAM forged pistons with gapless rings, and 0.02 inch undersized crankshaft. RAM Aircraft Limited Partnership. Lists TSIO-520 Series
- [STC SE3631SW](https://openairdocs.org/stc/SE3631SW): Cylinder modification. RAM Aircraft Limited Partnership. Lists TSIO-520 Series
- [STC SE3632SW](https://openairdocs.org/stc/SE3632SW): Installation of induction hose clamps. RAM Aircraft Limited Partnership
- [STC SE3683SW](https://openairdocs.org/stc/SE3683SW): Installation of alternator clutch hub Teledyne part no. 640934 with Teledyne part no. 642056 alternator. This mod has been found to be compatible with STC SE4327SW and SE3714SW. RAM Aircraft Limited Partnership
- [STC SE5455SW](https://openairdocs.org/stc/SE5455SW): Unpressurized Slick 6220 magnetos. RAM Aircraft Limited Partnership
- [STC SE09513SC](https://openairdocs.org/stc/SE09513SC): Installation and usage of Exxon 20W50 Multigrade aircraft engine oil conforming to Exxon Oil Formulation WS-3013. Exxon Company USA. Lists TSIO-520 Series
- [STC SE09559SC](https://openairdocs.org/stc/SE09559SC): Installation of US Airparts roller rocker arm assemblies P/N US92E exhaust and US92I intake. US Airparts, Inc
- [STC SE55WE](https://openairdocs.org/stc/SE55WE): Modification of fuel injection manifold valve P/N 626547 to the P/N 631427 or P/N 636326 configuration. AAR Aircraft Services Inc. d/b/a AAR Aircraft Services-Oklahoma. Lists TSIO-520 Series
- [STC SE09289SC](https://openairdocs.org/stc/SE09289SC): Installation of modified fuel injector nozzles. General Aviation Modifications, Inc. Lists TSIO-520 Series
- [STC SE09319SC](https://openairdocs.org/stc/SE09319SC): Modify oil pan adding a new oil sump drain. Texas Skyways Inc. Lists TSIO-520 Series
- [STC SE00350SE](https://openairdocs.org/stc/SE00350SE): Installation of sump mounted chip detector. Aviation Development Corporation
- [STC SE8687SW](https://openairdocs.org/stc/SE8687SW): Regrooving of pistons P/N 631475 or P/N 632585. Capehart Industries, Inc. Lists TSIO-520 Series
- [STC SE00005DE](https://openairdocs.org/stc/SE00005DE): Installation of engine oil filter adapter compatable with SA4094NM Oilamatic, Inc. engine preoiling system. Oilamatic Inc
- [STC SE8594SW](https://openairdocs.org/stc/SE8594SW): Installation of roller rocker arm P/N PE 92I intake and PE92E exhaust. Performance Engineering
- [STC SE7430SW](https://openairdocs.org/stc/SE7430SW): Installation of Performance Engineering roller rocker arms. Performance Engineering
- [STC SE452NE](https://openairdocs.org/stc/SE452NE): Installation and usage of 'Mobil AV 1' aviation oil. Mobil Research & Development Corp. Lists TSIO-520 Series
- [STC SE3630SW](https://openairdocs.org/stc/SE3630SW): Crankcase modifications. RAM Aircraft Limited Partnership
- [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 TSIO-520 Series
- [STC SE244NE](https://openairdocs.org/stc/SE244NE): Installation of Mattituck plasma flame sprayed cylinder barrels in Teledyne reciprocating engines. Mattituck Airbase, Inc. Lists TSIO-520 Series
- [STC SE80NE](https://openairdocs.org/stc/SE80NE): Installation and usage of Bel-Ray synthetic aviation oil, Bel-Ray Aero 1, (nonsupercharged), horizontally opposed direct drive, aircraft engines of 350 hp. or less. Bel-Ray Company, Inc. Lists TSIO-520 Series
- [STC SE44GL](https://openairdocs.org/stc/SE44GL): Incorporation of a fuel flow transducer. Shadin Company Inc
- [STC SE44WE](https://openairdocs.org/stc/SE44WE): Use of Kling Aviation Oil, Specifications KL-100, KL-200 and KL-300 in Continental and Lycoming engines. Kling Oil Company. Lists TSIO-520 Series
- [STC SE09653SC](https://openairdocs.org/stc/SE09653SC) (historical): Installation of RAM Induction Equalized Fuel Nozzle Set. RAM Aircraft Limited Partnership
- [STC SE09280SC](https://openairdocs.org/stc/SE09280SC) (historical): Modify engine in accordance with RAM Aircraft Corporation Drawing No. 1888. RAM Aircraft Limited Partnership

All 52: https://openairdocs.org/engine/continental-tsio-520-bb/stcs.md

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