# N52271: 1945 Monocoupe 90AF

- Status: Valid registration
- Airframe: [Monocoupe 90AF](https://openairdocs.org/model/monocoupe-90af) (registry code 5810107, 2 seats)
- Engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505)
- Data sheets: [TCDS A-306](https://openairdocs.org/tcds/A-306) (Monocoupe Corporation), [TCDS E-223](https://openairdocs.org/tcds/E-223) (Lycoming Engines) (OpenAirDocs)
- Serial number: 860
- Year built: 1945
- Type: Fixed wing single engine
- Engine type: Reciprocating
- Airworthiness: Standard
- Airworthiness date: August 10, 1955
- Certificate issued: May 8, 2017
- Expires: May 31, 2027
- Mode S code: A693C3
- Registered owner: [Horizon Aviation](https://openairdocs.org/faa-owner/HORIZON%20AVIATION)
- Location: [Seneca, PA](https://openairdocs.org/faa-place/PA/Seneca)
- Owner type: Partnership
- Owner's area on the map: 41.3785° N, 79.6727° W: Placed by OpenAirDocs at the center of ZIP code 16346, within about 2 miles (OpenAirDocs). The owner's mailing address, not where the aircraft is based
- FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=52271
- Page: https://openairdocs.org/aircraft/N52271

From the FAA registry file of October 24, 2026. ADs below are matched by the registry's airframe and engine model codes. They may apply; each AD's applicability can narrow it by serial number, part number or installed equipment. This is not a compliance determination. The registry lists only the engine series, so ADs for every Lycoming 0-235 model are included.

## ADs that may apply (OpenAirDocs): 21 in force

### Matched by airframe (Monocoupe 90AF)

None in force.

### Matched by engine (Lycoming 0-235 series)

- [AD 2026-17-10](https://openairdocs.org/ad/2026-17-10): Reciprocating Engine Cylinder Section · Lycoming Engines O-235, O-235-A, O-235-AP and 159 more. Effective Sep 14, 2026
- [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 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 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 2012-03-07](https://openairdocs.org/ad/2012-03-07): Carburetor · Lycoming Engines GO-435, GO-435-C2 (O-435-17), GO-435-C2A and 389 more. Effective Mar 27, 2012
- [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 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 98-01-06](https://openairdocs.org/ad/98-01-06): Carburetors · Continental Motors A-65-1, A-65-12, A-65-12F and 184 more. Effective Feb 13, 1998
- [AD 96-09-10](https://openairdocs.org/ad/96-09-10): Oil pump · Lycoming Engines AEIO-320-E1A, AEIO-320-E1B, AEIO-320-E2A and 334 more. Effective Jul 15, 1996
- [AD 95-26-02](https://openairdocs.org/ad/95-26-02): Aviation Gasoline · Lycoming Engines IO-320-B1A, IO-320-B1B, IO-320-B1C and 182 more. Effective Jan 24, 1996
- [AD 95-03-10](https://openairdocs.org/ad/95-03-10): Push Rods · Lycoming Engines O-235, O-235-A, O-235-AP and 38 more. Effective Jan 24, 1996
- [AD 93-19-04](https://openairdocs.org/ad/93-19-04): Carburetors · Continental Motors A-65-1, A-65-12, A-65-12F and 184 more. Effective Oct 18, 1993
- [AD 90-04-06 R1](https://openairdocs.org/ad/90-04-06-R1): Propeller Governor External Oil Line · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 427 more. Effective May 28, 1991
- [AD 88-02-04](https://openairdocs.org/ad/88-02-04): Carburetors · Lycoming Engines O-235-C1C, O-235-H2C, O-235-L2A and 4 more. Effective Feb 1, 1988
- [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 80-25-02 R2](https://openairdocs.org/ad/80-25-02-R2): Pushrods · Lycoming Engines O-235, O-235-A, O-235-AP and 30 more. Effective Jan 13, 1981
- [AD 80-06-05](https://openairdocs.org/ad/80-06-05): Magnetos · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 254 more. Effective Mar 28, 1980
- [AD 78-25-01](https://openairdocs.org/ad/78-25-01): Condensers · Lycoming Engines O-235-L2C. Effective Dec 8, 1978
- [AD 75-08-09](https://openairdocs.org/ad/75-08-09): Oil Pump Drive Shaft · Lycoming Engines AEIO-360-A1B, AEIO-360-A1B6, AEIO-360-A1C and 365 more. Effective Aug 18, 1977
- [AD 69-24-03](https://openairdocs.org/ad/69-24-03): Carburetors · Continental Motors A-65-1, A-65-12, A-65-12F and 321 more. Effective Nov 29, 1969
- [AD 66-06-03](https://openairdocs.org/ad/66-06-03): Connecting Rod Assemblies · Lycoming Engines GO-435-C2 (O-435-17), GO-435-C2A, GO-435-C2A2 and 317 more. Effective Jan 16, 1969

### Historical (superseded or no longer in force)

- [AD 2024-21-02](https://openairdocs.org/ad/2024-21-02) (historical): Engine (Reciprocating) · Lycoming Engines AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 548 more. Effective Dec 5, 2024
- [AD 81-18-04 R2](https://openairdocs.org/ad/81-18-04-R2) (historical): Engine Oil Pump Driven Impeller and Shaft · Textron Lycoming, AVCO AEIO-320-D1B, AEIO-320-D2B, AEIO-320-E1A and 376 more. Effective Jun 7, 1982

## Information bulletins (advisory) (5 in force)

- [SAIB NE-19-08](https://openairdocs.org/saib/NE-19-08): Reciprocating Engine Cylinder Section - Lycoming Engines Parallel Valve Cylinders. Issued May 2, 2019
- [SAIB NE-14-13](https://openairdocs.org/saib/NE-14-13): Reciprocating Engine - Cylinder Mounting Studs. Issued Mar 24, 2014
- [SAIB NE-06-32R1](https://openairdocs.org/saib/NE-06-32R1): Reciprocating Engine - Crankshaft. Issued Sep 10, 2008
- [SAIB NE-05-89](https://openairdocs.org/saib/NE-05-89): . Issued Sep 30, 2005
- [SAIB NE-01-22](https://openairdocs.org/saib/NE-01-22): . Issued May 11, 2001

## NTSB investigations

None matched to N52271.

## FAA accident and incident reports

None matched to N52271.

## Service difficulty reports

None filed for this aircraft. Matched to this aircraft by N-number and event date, checked against the reported serial number, make and model.

## STCs that may be installed (OpenAirDocs) (60, first 50)

Approved for this aircraft's airframe or engine model, in force first, then newest. The registry doesn't record which STCs an aircraft has; its records do.

### Approved for the airframe (Monocoupe 90AF)

- [STC SA04652CH](https://openairdocs.org/stc/SA04652CH): To allow use of 100R grade aviation fuel meeting Swift Fuel, LLC specification. Swift Fuels LLC
- [STC SA00081NY](https://openairdocs.org/stc/SA00081NY): Installation of Iceman Aviation Supplies, Inc. Carburetor Ice Detector. Alcor LLC
- [STC SA7965SW](https://openairdocs.org/stc/SA7965SW): Application of fabric and polyurethane finishing system. Shady Aviation LLC
- [STC SA02594SE](https://openairdocs.org/stc/SA02594SE): SkyView HDX Instrumentation and Autopilot System manufactured. Dynon Avionics
- [STC SA01967WI](https://openairdocs.org/stc/SA01967WI): Use of GAMI G100UL High Octane Unleaded Avgas. General Aviation Modifications Inc
- [STC SA04776NY](https://openairdocs.org/stc/SA04776NY): The HIPEC Covering and Finishing System must be performed and maintained. HIPEC Aircraft Coatings Inc
- [STC SA01734SE](https://openairdocs.org/stc/SA01734SE): Application of Stewart Systems synthetic fabric covering system to aircraft fuselage, wings, tail surfaces, control surfaces and related parts. Andrew D. Humphrey
- [STC SA00478CH](https://openairdocs.org/stc/SA00478CH): Installation of Cooper Superflite 102 Fabric. Aviation Products Systems Inc
- [STC SA8075SW](https://openairdocs.org/stc/SA8075SW): Installation of fiberglass covering. (M-62 SERIES PT-19) (G-73 SCHWEIZER). Razorback Fabrics Inc
- [STC SA489EA](https://openairdocs.org/stc/SA489EA): Installation of ARP Inc. carburetor ice detection system. Aircraft & Rotorcraft Products (ARP) Inc
- [STC SA2-952](https://openairdocs.org/stc/SA2-952): Installation of fiberglass covering. Razorback Fabrics Inc. Lists 90 Series
- [STC SA5159NM](https://openairdocs.org/stc/SA5159NM): Installation of chip detector system. Northwest Aircraft Inc. Lists 90 Series
- [STC SA1351WE](https://openairdocs.org/stc/SA1351WE): Replace existing fabric on wings, fuselage, empennage, and/or control surfaces, with Ceconite101 material. (262A Series -12). Ceconite Inc
- [STC SA308EA](https://openairdocs.org/stc/SA308EA): Installation of carburetor ice detection system 105AP in single and twin engine aircraft and single engine helicopters powered by Continental, Franklin, and Lycoming type engines equipped with Marvel-Schebler MA-2, MA-3, MA-4, MA-4-5, MA-6 and HA-6 series carburetors. (Normal,Utility and Acrobatic Category airplanes and helicopters equipped with engines and carburetors as described.). Alfred R Puccinelli
- [STC SA4-1024](https://openairdocs.org/stc/SA4-1024): Ceconite 101 covering of complete airplane. Cooper Engineering Corporation. Lists 90 Series

### Approved for the engine (Lycoming 0-235 series)

- [STC SE04651CH](https://openairdocs.org/stc/SE04651CH): To allow use of l00R grade aviation fuel meeting Swift Fuel, LLC specification SPEC-l00R-22. Swift Fuels LLC
- [STC SE00825WI](https://openairdocs.org/stc/SE00825WI): Installation of Specialty Products Spin-on oil filter on Lycoming Engines. B & C Specialty Products Inc
- [STC SE2932SW](https://openairdocs.org/stc/SE2932SW): Install carburetor air temperature indicator. Approved for Aircooled Motors (Franklin Engine Co.) equipped with float carburetors. Model eligibility included here may not be inclusive. Alcor LLC
- [STC SE208SO](https://openairdocs.org/stc/SE208SO): Installation of ice indicator in the carburetor. LegacySTC.com
- [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 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 SE2393CE](https://openairdocs.org/stc/SE2393CE): Installation of B&C Speciality Products lightweight (10.2 pounds) engine starter, part number BC-315-100-1 (12 volts) or part number BC-315-100-3 (24 volts). B & C Specialty Products Inc
- [STC SE03232CH](https://openairdocs.org/stc/SE03232CH): Installation of Engine Preheat Kit p/n TA2925-1 for 115 volt application. Hartzell Propeller Inc
- [STC SE04577CH](https://openairdocs.org/stc/SE04577CH): Install an electronic engine ignition system. Electroair Acquisition Corp. Lists O-235-A
- [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. Lists O-235-A
- [STC SE8628SW](https://openairdocs.org/stc/SE8628SW): Installation of oil nozzles for lubrication of cam and filters. Cygnet Aerospace Corp. Lists O-235-C1
- [STC SE792NW](https://openairdocs.org/stc/SE792NW): Modification of a Lycoming0-235-L2C, or 0-235-L2A engine to increase HP rating from 115-HP at 2700 rpm to a continuous125 HP at 2800 rpm. 4J's Aviation. Lists O-235-L2A
- [STC SE8776SW](https://openairdocs.org/stc/SE8776SW): Installation of coated cylinders and piston rings. Continental Motors, Inc
- [STC SE00218NY](https://openairdocs.org/stc/SE00218NY): Replacement of Lycoming starter with SKY-TEC 12 volt starter installed. Hartzell Engine Technologies, LLC
- [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 SE00357NY](https://openairdocs.org/stc/SE00357NY): Replacement of Lycoming starter with SKY-TEC 24-volt starter installed. Hartzell Engine Technologies, LLC
- [STC SE2901NM](https://openairdocs.org/stc/SE2901NM): Lycoming valve cover gasket. Real Gaskets Tennessee
- [STC SE888GL](https://openairdocs.org/stc/SE888GL): Replacement of Bendix S4LN-20, -21, -1209, or -1227 model magnetos with Slick model 4250 and 4251 magnetos. Champion Aerospace LLC. Lists O-235-C1
- [STC SE3877NM](https://openairdocs.org/stc/SE3877NM): Modification of a Lycoming O-235-L2C engine to increase the horsepower rating from 115 HP @ 2700 RPM to a continuous 125 HP @ 2800 RPM. Kai V. Nielsen. Lists O-235-L2C
- [STC SE8707SW](https://openairdocs.org/stc/SE8707SW): Alteration of Lycoming O-235 engine to allow use of ethanol fuel. Shauck Dr Maxwell E Jr. Lists O-235-C1
- [STC SE01930NY](https://openairdocs.org/stc/SE01930NY): Installation of Casper Labs 90 degree oil filter housing adapter. Casper Labs Inc
- [STC SE01943CH](https://openairdocs.org/stc/SE01943CH): Add the following approved fuels: unleaded automotive gasoline 87 minimum antiknock index, per ASTM Specification D-439 or D-4814 of any volatility class, A through E, or 82UL AVGAS per ASTM D-6227. Experimental Aircraft Association Inc. Lists O-235-C1
- [STC SE790GL](https://openairdocs.org/stc/SE790GL): Superseded by STC SE01943CH. Replace Lycoming piston number LW-13623 with Lycoming piston number 73851. EAA Aviation Foundation. Lists O-235-K2C
- [STC SE1779NM](https://openairdocs.org/stc/SE1779NM): Installation of Precise Flight, Inc. Standby Vacuum System SVS III. Precise Flight Inc
- [STC SE5743NM](https://openairdocs.org/stc/SE5743NM): Intallation of adapter for externally mounted oil filter. Aviation Development Corporation
- [STC SE00988CH](https://openairdocs.org/stc/SE00988CH): Modify Lycoming aircraft engine Model O-235-C2C rated at maximum continuous 108 hp at 2600 rpm and 6.75:1 compression ratio to maximum continuous 115 at 2700 rpm and 8.5:1 compression ratio. Precision Engine. Lists O-235-C2C
- [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
- [STC SE00350SE](https://openairdocs.org/stc/SE00350SE): Installation of sump mounted chip detector. Aviation Development Corporation
- [STC SE5173NM](https://openairdocs.org/stc/SE5173NM): Installation of a replacement oil cooler adaptor, P/N ADC-310. Aviation Development Corporation
- [STC SE2203NM](https://openairdocs.org/stc/SE2203NM): Installation of high compression pistons. Godwin John B Jr. Lists O-235-L2C
- [STC SE8023SW](https://openairdocs.org/stc/SE8023SW): Installation and usage of AEROSHELL. Shell Development Co
- [STC SE2606CE](https://openairdocs.org/stc/SE2606CE): Add unleaded and leaded automotive gasoline, 91 minimum antiknock index(RON+MON)/2 per ASTM Specification D-439. Petersen Aviation Inc. Lists O-235-L2A
- [STC SE452NE](https://openairdocs.org/stc/SE452NE): Installation and usage of 'Mobil AV 1' aviation oil. Mobil Research & Development Corp
- [STC SE2035CE](https://openairdocs.org/stc/SE2035CE): Add the following approved fuel: unleaded automotive gasoline, 87 minimum antiknock index and leaded automotive gasoline, 88 minimum antiknock index (RON+MON)/2. Intermixing with aviation gasoline also approved. Petersen Aviation Inc. Lists O-235-C1

All 60: https://openairdocs.org/aircraft/N52271/stcs.md

## Related

- Other Monocoupe 90AF aircraft: https://openairdocs.org/model/monocoupe-90af/aircraft.md
- The Lycoming 0-235 series engine: https://openairdocs.org/engine/lycoming-0-235-series.md

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