# N996B: 1955 Bell 47H-1 - Status: Valid registration - Airframe: [Bell 47H-1](https://openairdocs.org/model/bell-47h-1) (registry code 1181011, 3 seats) - Engine: [Franklin 6V4 series](https://openairdocs.org/engine/franklin-6v4-series) (registry code 27033) - Data sheets: [TCDS H-1](https://openairdocs.org/tcds/H-1) (Scott's-Bell 47 Inc), [TCDS E-244](https://openairdocs.org/tcds/E-244) (Franklin Sp. z.o.o.) (OpenAirDocs) - Serial number: 1349 - Year built: 1955 - Type: Rotorcraft - Engine type: Reciprocating - Airworthiness: Experimental, research and development - Certificate issued: July 30, 2003 - Expires: October 31, 2027 - Mode S code: ADE906 - Registered owner: [Niagara Aerospace Museum](https://openairdocs.org/faa-owner/NIAGARA%20AEROSPACE%20MUSEUM) - Location: [Niagara Falls, NY](https://openairdocs.org/faa-place/NY/Niagara%20Falls) - Owner type: Corporation - Owner's area on the map: 43.1050° N, 78.9480° W: Placed by OpenAirDocs at the center of ZIP code 14304, within about 3 miles (OpenAirDocs). The owner's mailing address, not where the aircraft is based - FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=996B - Page: https://openairdocs.org/aircraft/N996B 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): 56 in force ### Matched by airframe (Bell 47H-1) - [AD 2023-11-07](https://openairdocs.org/ad/2023-11-07): Ground Proximity System · Airbus Helicopters 47, 206, 210 and 237 more. Effective Jun 22, 2023 - [AD 2009-12-01](https://openairdocs.org/ad/2009-12-01): Main rotor blade box beam clip (clip) · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Jun 29, 2009 - [AD 2001-17-17](https://openairdocs.org/ad/2001-17-17): Main Rotor Blade Grip Threads · Scotts-Bell 47 47B, 47B3, 47D and 19 more. Effective Oct 3, 2001 - [AD 98-07-09](https://openairdocs.org/ad/98-07-09): Stabilizer Bar Damper Link Assembly · Scotts-Bell 47 47B, 47B3, 47D and 19 more. Effective May 6, 1998 - [AD 96-06-12](https://openairdocs.org/ad/96-06-12): Inspect Tail Rotor Blade & Abrasion Strip · Scotts-Bell 47 47B, 47B3, 47D and 19 more. Effective May 29, 1996 - [AD 85-15-04](https://openairdocs.org/ad/85-15-04): Tail Rotor Blade Yolk P/N 74-641-057-9 · Scotts-Bell 47 47B, 47B3, 47D and 7 more. Effective Jan 8, 1986 - [AD 85-08-03](https://openairdocs.org/ad/85-08-03): Tail Rotor Blade Assemblies · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Apr 29, 1985 - [AD 81-17-01](https://openairdocs.org/ad/81-17-01): Starting Vibrator Assemblies · Bendix Starting Vibrator Assemblies, B-2, B-2A and 49 more. Effective Aug 13, 1981 - [AD 80-10-04 R1](https://openairdocs.org/ad/80-10-04-R1): Tail Rotor Blades · Continental Copters OH-13H, OH-13E, OH-13E and 26 more. Effective Feb 28, 1981 - [AD 81-04-03](https://openairdocs.org/ad/81-04-03): Tail Rotor Drive Assembly · Continental Copters OH-13H, OH-13E, OH-13E and 26 more. Effective Feb 2, 1981 - [AD 80-21-09 R1](https://openairdocs.org/ad/80-21-09-R1): Tail Rotor Pitch Link · Continental Copters OH-13H, OH-13E, OH-13E and 26 more. Effective Nov 24, 1980 - [AD 78-03-01](https://openairdocs.org/ad/78-03-01): Hopper Support Bracket (STC SH357SW) · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Mar 6, 1978 - [AD 77-21-01](https://openairdocs.org/ad/77-21-01): Tail Rotor Gear Boxes · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Nov 14, 1977 - [AD 70-10-08](https://openairdocs.org/ad/70-10-08): Tail Rotor Grips · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Jul 20, 1976 - [AD 76-12-02](https://openairdocs.org/ad/76-12-02): Tail Rotor Yoke · Scotts-Bell 47 47B, 47B3, 47D and 5 more. Effective Jul 14, 1976 - [AD 76-12-01](https://openairdocs.org/ad/76-12-01): Tail Rotor Hub Bolt · Scotts-Bell 47 47B, 47B3, 47D and 4 more. Effective Jul 14, 1976 - [AD 75-18-06](https://openairdocs.org/ad/75-18-06): Tail Rotor Pitch Control · Scotts-Bell 47 47B, 47B3, 47D and 5 more. Effective Sep 19, 1975 - [AD 74-08-02](https://openairdocs.org/ad/74-08-02): Mast Control Stabilizer Bar Assembly · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Jun 14, 1974 - [AD 74-07-01](https://openairdocs.org/ad/74-07-01): Main Rotor Control Tube Assembly · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective May 30, 1974 - [AD 73-19-04](https://openairdocs.org/ad/73-19-04): Main Rotor Blade Grip · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Oct 10, 1973 - [AD 70-08-02](https://openairdocs.org/ad/70-08-02): Tail Rotor Drive Shaft · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Jan 1, 1971 - [AD 70-14-01](https://openairdocs.org/ad/70-14-01): Tail Rotor Pitch · Scotts-Bell 47 47D1, 47G, 47G-2 and 1 more. Effective Aug 17, 1970 - [AD 70-14-02](https://openairdocs.org/ad/70-14-02): Tail Rotor Hub Assembly Bolt · Scotts-Bell 47 47D, 47D1, 47G and 2 more. Effective Aug 10, 1970 - [AD 70-11-04](https://openairdocs.org/ad/70-11-04): Wood Main Rotor Blades · Scotts-Bell 47 47B, 47B3, 47D and 4 more. Effective Jun 26, 1970 - [AD 65-04-01](https://openairdocs.org/ad/65-04-01): Freewheeling Clutch · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Feb 17, 1965 - [AD 62-27-02](https://openairdocs.org/ad/62-27-02): Wood Tail Rotor Blades · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Jan 29, 1963 - [AD 62-23-02](https://openairdocs.org/ad/62-23-02): Main Rotor Mast Thrust Bearing · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Oct 29, 1962 - [AD 61-22-01](https://openairdocs.org/ad/61-22-01): Pitch Link Rod End Bearing · Scotts-Bell 47 47, 47B, 47B3 and 21 more. Effective Nov 7, 1961 - [AD 60-10-01](https://openairdocs.org/ad/60-10-01): Scissor Lever Bolts · Scotts-Bell 47 47B, 47B3, 47D and 7 more - [AD 73-19-02](https://openairdocs.org/ad/73-19-02): Tail Rotor Yoke · Scotts-Bell 47 47B, 47B3, 47D and 5 more - [AD 59-05-01](https://openairdocs.org/ad/59-05-01): Tail Rotor Blade Inspection · Scotts-Bell 47 47, 47B, 47B3 and 21 more - [AD 58-26-02](https://openairdocs.org/ad/58-26-02): M-S MA4-5AA Carburetor · Scotts-Bell 47 47, 47B, 47B3 and 21 more - [AD 58-23-01](https://openairdocs.org/ad/58-23-01): Tail Rotor Pitch Change Bearings · Scotts-Bell 47 47B, 47B3, 47D and 4 more - [AD 57-12-04](https://openairdocs.org/ad/57-12-04): Tail Rotor Blade Inspection · Scotts-Bell 47 47B, 47B3, 47D and 5 more - [AD 57-12-02](https://openairdocs.org/ad/57-12-02): Tail Boom Attach Fittings · Scotts-Bell 47 47H-1 - [AD 57-12-01](https://openairdocs.org/ad/57-12-01): Elevator Control Alinement · Scotts-Bell 47 47H-1 - [AD 57-08-02](https://openairdocs.org/ad/57-08-02): Parker Check Valve · Scotts-Bell 47 47B3, 47D, 47D1 and 2 more - [AD 57-08-01](https://openairdocs.org/ad/57-08-01): Tail Rotor Drive Shafts · Scotts-Bell 47 47, 47B, 47B3 and 21 more - [AD 57-07-02](https://openairdocs.org/ad/57-07-02): Rotor Hub Equalizer Link · Scotts-Bell 47 47, 47B, 47B3 and 21 more - [AD 57-07-01](https://openairdocs.org/ad/57-07-01): Elevator Inspection and Rework · Scotts-Bell 47 47H-1 - [AD 56-25-02](https://openairdocs.org/ad/56-25-02): Tail Rotor Pitch Bearings · Scotts-Bell 47 47, 47B, 47B3 and 21 more - [AD 56-21-01](https://openairdocs.org/ad/56-21-01): Hydraulic Boost Cylinders · Scotts-Bell 47 47G, 47G-2 and 47H-1 - [AD 56-20-03](https://openairdocs.org/ad/56-20-03): Tail Rotor Hub Bolts · Scotts-Bell 47 47B, 47B3, 47D and 4 more - [AD 56-15-03](https://openairdocs.org/ad/56-15-03): Elevator Control System · Scotts-Bell 47 47H-1 - [AD 56-15-02](https://openairdocs.org/ad/56-15-02): Swashplate Control Ring · Scotts-Bell 47 47, 47B, 47B3 and 21 more - [AD 56-15-01](https://openairdocs.org/ad/56-15-01): Antitorque Control System · Scotts-Bell 47 47H-1 - [AD 56-05-01](https://openairdocs.org/ad/56-05-01): Tail Rotor Drive Shafts · Scotts-Bell 47 47, 47B, 47B3 and 21 more - [AD 55-16-01](https://openairdocs.org/ad/55-16-01): Tail Rotor Hub Fillet · Scotts-Bell 47 47, 47B, 47B3 and 21 more - [AD 52-28-03](https://openairdocs.org/ad/52-28-03): Tail Rotor Gearbox Shaft · Scotts-Bell 47 47, 47B, 47B3 and 21 more - [AD 52-21-01](https://openairdocs.org/ad/52-21-01): Lord Mount Guards · Scotts-Bell 47 47, 47B, 47B3 and 21 more ### 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 ### Historical (superseded or no longer in force) - [AD 2021-23-13](https://openairdocs.org/ad/2021-23-13) (historical): Ground Proximity System · Airbus Helicopters K-225, K-190A, K-240 and 237 more. Effective Dec 9, 2021 - [AD 2000-18-51](https://openairdocs.org/ad/2000-18-51) (historical): Main Rotor Blade Grip · Bell Helicopter Textron 47B, 47B3, 47D and 19 more. Effective Nov 30, 2000 - [AD 86-06-08 R1](https://openairdocs.org/ad/86-06-08-R1) (historical): Main Rotor Blade Grips · Bell Helicopter Textron 47B, 47B3, 47D and 25 more. Effective Jul 10, 1987 All 59: https://openairdocs.org/aircraft/N996B/ads.md ## Information bulletins (advisory) None matched. ## NTSB investigations (2) 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 FTW69F0246](https://openairdocs.org/ntsb/FTW69F0246), Oct 5, 1968: Bell 47H-1 (N996B), Houston, TX, substantial damage - [NTSB NYC66A0044](https://openairdocs.org/ntsb/NYC66A0044), Oct 2, 1965: Bell 47H-1 (N996B), Clinton, MD, substantial damage ## 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 19880824065469I](https://openairdocs.org/incident/19880824065469I), Aug 24, 1988: Bell 47H1 (N996B), Torrance, CA. Engine quit. Autorotation to airport. Found plug lodged in oil passage of the oil pump. Improper maintenance. ## 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) (107, 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 (Bell 47H-1) - [STC SA800EA](https://openairdocs.org/stc/SA800EA): Installation of Whelen Anti-Collision, Position, or Anti-Collision/Position Light System, and applicable associated power supplies. Whelen Aerospace Technologies - [STC SA5581SW](https://openairdocs.org/stc/SA5581SW): Installation of ALCOR true-flow/ totalizer system. Alcor LLC. Lists 47 Series - [STC SH3319NM](https://openairdocs.org/stc/SH3319NM): Installation of Precise Flight Pulselite Control Unit in the Landing /Taxi Recognition Visual Control Light system,. Precise Flight Inc - [STC SR09066RC](https://openairdocs.org/stc/SR09066RC): Fabricate the HAC-47-3 Tail Rotor Blade. Scott's-Bell 47 Inc - [STC SR02704SE](https://openairdocs.org/stc/SR02704SE): Installation and maintenance of the Sunspot 36 and 46 series lights. AeroLED's Holdings LLC - [STC SA02268CH](https://openairdocs.org/stc/SA02268CH): Installation of Airwolf Filter Corp. Air Oil Separator. Airwolf Filter Corporation - [STC SA615EA](https://openairdocs.org/stc/SA615EA): Installation of a Whelen Anti-Collision Strobe Light System as replacement for originally installed anti-collision lights. Whelen Aerospace Technologies - [STC SR00359BO](https://openairdocs.org/stc/SR00359BO): Installation of Parmetheus Plus LED PAR36 and PAR46 taxi and landing lights. Whelen Aerospace Technologies - [STC SR00408NY](https://openairdocs.org/stc/SR00408NY): Installation of Airwolf remote mounted engine oil filter model AFC-600. Airwolf Filter Corporation - [STC SR02487AK](https://openairdocs.org/stc/SR02487AK): Installation of L-3 Communications Avionics Systems ESI-500 Standby Instrument System. ADS-B Technologies, LLC - [STC SR02470AK](https://openairdocs.org/stc/SR02470AK): Installation of the L-3 Communications NGT -1000/2000/2500 ADS-B System. ADS-B Technologies, LLC - [STC SR02471AK](https://openairdocs.org/stc/SR02471AK): Installation of the L-3 Communications NGT -9000/9000R ADS-B System. ADS-B Technologies, LLC - [STC SR02394AK](https://openairdocs.org/stc/SR02394AK): Replacement of existing landing and/or hover light bulbs with Light Emitting Diode (LED) lighting system. Seaplanes North LLC - [STC SH279SW](https://openairdocs.org/stc/SH279SW): Modification of dual control cyclic stick into quick removable stick similar to Bell 47A stick by cutting off the stick and making an insert of 4130 steel tube to fit inside. Scott's Bell 47 Inc - [STC SH382SW](https://openairdocs.org/stc/SH382SW): Eligible only on Bell 47 series with open tail booms. Installation of sign per Kitz Kopter's Drawing KK-101 dated 10/14/64. Scott's Bell 47 Inc - [STC SR09321RC](https://openairdocs.org/stc/SR09321RC): Installation of Improved Main Rotor Grips and Matching Adapter Nut. Scott's Bell 47 Inc - [STC SR09341RC](https://openairdocs.org/stc/SR09341RC): Installation of the main rotor grips with integral drag brace clevis, new drag brace, and matching adapter nut for wood blade configurations. Scott's Bell 47 Inc - [STC SH909SW](https://openairdocs.org/stc/SH909SW): Installation of Franklin 6V-350-A engine, derated to 200 HP. Limited to installation on serial number 1355 ONLY. Texas Helicopter Co. Inc - [STC SA00068SE](https://openairdocs.org/stc/SA00068SE): Installation of fuel flow/pressure instruments. (W/TSIO-360-MB1). Electronics International Inc - [STC SA2693NM](https://openairdocs.org/stc/SA2693NM): Installation of Electronics International digital volt/amp gauges and accessories. Electronics International Inc - [STC SA4172NM](https://openairdocs.org/stc/SA4172NM): Installation of Aviation Development oil filter. Aviation Development Corporation - [STC SA02033AT](https://openairdocs.org/stc/SA02033AT): Modification to install an air-oil separator to prevent oil from being aspirated from the engine breather line. M-20 Oil Separators LLC - [STC SA00680SE](https://openairdocs.org/stc/SA00680SE): Installation of Electronics International model UBG-16 or UBG-16T bar graph engine analyzer. Electronics International - [STC SA489EA](https://openairdocs.org/stc/SA489EA): Installation of ARP Inc. carburetor ice detection system. Aircraft & Rotorcraft Products (ARP) Inc - [STC SA02520AT](https://openairdocs.org/stc/SA02520AT): Installation of M-20 Oil Separator, model 600-WP. M-20 Oil Separators LLC - [STC SA2687NM](https://openairdocs.org/stc/SA2687NM): Installation of Truboplus/ Electronics Int'l gauges and switches. Aero Manufacturing Inc - [STC SA1626NM PAGE 1](https://openairdocs.org/stc/SA1626NM%20PAGE%201): Installation of Electronics Int'l Digital EGT/CHT Instruments and accessories. (201 Series). Electronics International - [STC SA2350NM PAGE 1](https://openairdocs.org/stc/SA2350NM%20PAGE%201): Installation of Electronics International Inc digital carburetor/outside air temperature gauges. Electronics International - [STC SA4302NM](https://openairdocs.org/stc/SA4302NM): Installation of Electronics Int'l digital automatic engine analyzer. Electronics International - [STC SA3862NM PAGE 1](https://openairdocs.org/stc/SA3862NM%20PAGE%201): Installation of Electronics International Primary TIT/EGT/CHT instruments, remote switches and associated accessories. Electronics International - [STC SA4173NM](https://openairdocs.org/stc/SA4173NM): Installation of Simplex Model 7600 modular electrical system. (47G-5 WITH 12 VOLT SYSTEM). Simplex Manufacturing Company. Lists 47 Series - [STC SH4173NM](https://openairdocs.org/stc/SH4173NM): Installation of Simplex Model 7600 modular electrical system. (US ARMY OH-13E M74A). Simplex Manufacturing Company - [STC SH2945NM](https://openairdocs.org/stc/SH2945NM): Addition of a twist grip on the cyclic pitch stick to provide hand operated yaw control. Narad James L - [STC SH3351NM](https://openairdocs.org/stc/SH3351NM): Addition of a twist grip on the cyclic pitch stick to provide a hand operated yaw control. Narad James L. Lists 47 Series - [STC SA2190NM PAGE 1](https://openairdocs.org/stc/SA2190NM%20PAGE%201): Installation of electronics International Digital Volt/Amp Gauges and Accessories. Electronics International - [STC SH2231NM](https://openairdocs.org/stc/SH2231NM): Installation of Pheromone aerial application system. (47H-1 Restricted cat.). Herculite Products, Inc - [STC SH506GL](https://openairdocs.org/stc/SH506GL): Installation of modified tail rotor gearbox using original installation hardware and components. Helicopters, Inc - [STC SH25SW](https://openairdocs.org/stc/SH25SW): Transceivers KY90, KY90E, KY90H, KY95, KY95E, and KY95H. Honeywell International Inc. Lists 47 Series - [STC SH828NW](https://openairdocs.org/stc/SH828NW): Installation of weighing system. (AS MODIFIED BY STC SH657NW). Onboard Weighing Systems - [STC SH95WE](https://openairdocs.org/stc/SH95WE): Installation of low profile spray system. Simplex Manufacturing Co. Lists 47 Series - [STC SH200WE](https://openairdocs.org/stc/SH200WE): Installation of stirrup assemblies to directional control pedals for operation by handicapped pilot. Dallwig Barry C - [STC SH214NW](https://openairdocs.org/stc/SH214NW): Installation of Simplex Model 4100 Aerial Dust System. Simplex Manufacturing Co - [STC SH169WE](https://openairdocs.org/stc/SH169WE): Installation of exhaust muffler assembly. Lear Avia Corporation - [STC SH252SW](https://openairdocs.org/stc/SH252SW): Bendix 100-ampere generator30E16-11C. Ward Intl Aircraft Service. Lists 47 Series - [STC SH5-25](https://openairdocs.org/stc/SH5-25): Installation of tundra snow shoes. ERA Helicopters, Inc. Lists 47 Series - [STC SH4-1512](https://openairdocs.org/stc/SH4-1512): Installation of adapter assembly for bomb shackel, or cargo hook. USDA Forest Service. Lists 47 Series - [STC SH101WE](https://openairdocs.org/stc/SH101WE): Replacement of existing 50 ampere generator with 100 ampere RWS-985-1340 generator. Aviation Power Supply Inc. Lists 47 Series - [STC SH48WE](https://openairdocs.org/stc/SH48WE): Installation of turbosupercharged Lycoming TVO-435-B1A engine. Jobmaster Co Inc. Lists 47 Series - [STC SH176EA](https://openairdocs.org/stc/SH176EA): Stewart-Warner heater. E W Wiggins Airways Inc. Lists 47 Series - [STC SH479SW](https://openairdocs.org/stc/SH479SW): 6V350A engine. Franklin Engine Co Inc. Lists 47 Series All 107: https://openairdocs.org/aircraft/N996B/stcs.md ## Related - Other Bell 47H-1 aircraft: https://openairdocs.org/model/bell-47h-1/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.