# N234SM: 1955 Hiller OH-23C - Status: Valid registration - Airframe: [Hiller OH-23C](https://openairdocs.org/model/hiller-oh-23c) (registry code 4360119, 4 seats) - Engine: [Franklin 6V4 series](https://openairdocs.org/engine/franklin-6v4-series) (registry code 27033) - Data sheets: [TCDS 6H2](https://openairdocs.org/tcds/6H2) (Siam Hiller Holdings Inc.), [TCDS E-244](https://openairdocs.org/tcds/E-244) (Franklin Sp. z.o.o.) (OpenAirDocs) - Serial number: 55-4101 - Year built: 1955 - Type: Rotorcraft - Engine type: Reciprocating - Airworthiness: Standard, normal - Airworthiness date: November 12, 1993 - Certificate issued: February 2, 2023 - Expires: February 28, 2030 - Mode S code: A218F8 - Registered owner: [Robertson Kenneth W](https://openairdocs.org/faa-owner/ROBERTSON%20KENNETH%20W) - Location: [Sussex, NJ](https://openairdocs.org/faa-place/NJ/Sussex) - Owner type: Individual - Owner's area on the map: 41.2470° N, 74.6105° W: Placed by OpenAirDocs at the center of ZIP code 07461, within about 5 miles (OpenAirDocs). The owner's mailing address, not where the aircraft is based - FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=234SM - Page: https://openairdocs.org/aircraft/N234SM 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 Franklin 6V4 model are included. ## ADs that may apply (OpenAirDocs): 2 in force ### Matched by airframe (Hiller OH-23C) None in force. ### Matched by engine (Franklin 6V4 series) - [AD 69-09-01](https://openairdocs.org/ad/69-09-01): Eisemann Magnetos · Eisemann Magnetos, 2A4-45-B2, 2A4-49-B2 and 158 more - [AD 51-28-02](https://openairdocs.org/ad/51-28-02): Oil Pump Gears · Wytwornia Sprzetu Komunikacyjnego 6V4-178-B3, 6V4-178-B31, 6V4-178-B32 and 3 more ## Information bulletins (advisory) None matched. ## NTSB investigations (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB ATL96LA023](https://openairdocs.org/ntsb/ATL96LA023), Dec 18, 1995: Hiller 12C (N234SM), N. Myrtle Beach, SC, substantial damage. Probable cause: The pilot's improper operation of the flight controls during a practice autorotation, and the certified flight instructor's inadequate supervision of the operation ## 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. - [Accident 19951218041489A](https://openairdocs.org/incident/19951218041489A), Dec 18, 1995: Hiller OH23G (N234SM), North Myrtle Be, SC, Substantial damage. Practice autorotations. Flared nose high. Tail rotor struck the ground. Two pilots on board. ## 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) (6) 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 engine (Franklin 6V4 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. Lists 6V4-200-C32 - [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. Lists 6V4-178-B3 - [STC SE1311SO](https://openairdocs.org/stc/SE1311SO): Installation of Shivers carburetor temperature gauge with a Richter Aero Equipment B-5 carburetor temperature probe. LegacySTC.com. Lists 6V4-178-B3 - [STC SE03309CH](https://openairdocs.org/stc/SE03309CH): Installation of Engine Preheat Kit, p/n TSP6CYL-2927-115 for 115 volt application. Hartzell Propeller Inc. Lists 6V4-178-B3 - [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 6V4-178-B3 - [STC SE1-201](https://openairdocs.org/stc/SE1-201): Installation of the Richter Aero Equipment Type B-4 or B-5 Temperature Probe. (O-360 SERIES (excl. A1C, C2B, C2D)). MidContinent Instru Co Inc. Lists 6V4-178-B3 ## Related - Other Hiller OH-23C aircraft: https://openairdocs.org/model/hiller-oh-23c/aircraft.md - The Franklin 6V4 series engine: https://openairdocs.org/engine/franklin-6v4-series.md --- 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.