# N221MP: Enstrom Helicopter 280C - Status: Valid registration - Airframe: [Enstrom Helicopter 280C](https://openairdocs.org/model/enstrom-helicopter-280c) (registry code 3300505, 3 seats) - Data sheets: [TCDS H1CE](https://openairdocs.org/tcds/H1CE) (The Enstrom Helicopter Corporation) (OpenAirDocs) - Serial number: 1147 - Type: Rotorcraft - Engine type: Reciprocating - Certificate issued: September 23, 2024 - Expires: September 30, 2031 - Mode S code: A1E5D9 - Registered owner: [Benson Aviation LLC](https://openairdocs.org/faa-owner/BENSON%20AVIATION%20LLC) - Location: [Mehoopany, PA](https://openairdocs.org/faa-place/PA/Mehoopany) - Owner type: LLC - Owner's area on the map: 41.5176° N, 76.1413° W: Placed by OpenAirDocs at the center of ZIP code 18629, 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=221MP - Page: https://openairdocs.org/aircraft/N221MP From the FAA registry file of October 22, 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. ## ADs that may apply (OpenAirDocs): 27 in force ### Matched by airframe (Enstrom Helicopter 280C) - [AD 2023-09-09](https://openairdocs.org/ad/2023-09-09): Exhaust Turbine System (Recip) · Aerostar PA-60-600 (Aerostar 600), PA-60-601 (Aerostar 601), PA-60-601P (Aerostar 601P) and 292 more. Effective Jul 17, 2023 - [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 2018-02-01](https://openairdocs.org/ad/2018-02-01): Main Rotor Head · Enstrom Helicopter Corporation, The 280, 280C, 280F and 8 more. Effective Feb 21, 2018 - [AD 2017-26-03](https://openairdocs.org/ad/2017-26-03): Main Rotor System · Enstrom Helicopter Corporation, The 280, 280C, 280F and 11 more. Effective Jan 4, 2018 - [AD 2012-11-05](https://openairdocs.org/ad/2012-11-05): Main Rotor Control · Enstrom Helicopter Corporation, The 280C, 280F, 280FX and 6 more. Effective Jul 3, 2012 - [AD 2007-11-02](https://openairdocs.org/ad/2007-11-02): Main rotor push-pull control rod (push-pull rod) · Enstrom Helicopter Corporation, The 280, 280C, 280F and 7 more. Effective Oct 2, 2007 - [AD 2007-16-01](https://openairdocs.org/ad/2007-16-01): Main rotor blade retention pin (retention pin) · Enstrom Helicopter Corporation, The 280, 280C, 280F and 11 more. Effective Aug 15, 2007 - [AD 2002-08-03](https://openairdocs.org/ad/2002-08-03): Main Rotor Transmission and Radius of Upper Fillet of Shaft · Enstrom Helicopter Corporation, The 280, 280C, 280F and 21 more. Effective May 2, 2002 - [AD 97-20-04](https://openairdocs.org/ad/97-20-04): Voltage Regulator and Over-Voltage Relay · Enstrom Helicopter Corporation, The 280, 280C, F-28A and 1 more. Effective Oct 7, 1997 - [AD 96-06-02](https://openairdocs.org/ad/96-06-02): Swashplate Bearings · Enstrom Helicopter Corporation, The 280, 280C, F-28A and 2 more. Effective Apr 25, 1996 - [AD 96-06-03](https://openairdocs.org/ad/96-06-03): Main Rotor Transmission Clutch Assembly · Enstrom Helicopter Corporation, The 280, 280C, 280F and 6 more. Effective Apr 23, 1996 - [AD 94-17-15](https://openairdocs.org/ad/94-17-15): Main Rotor Feathering Bearing · Enstrom Helicopter Corporation, The 280, 280C, 280F and 5 more. Effective Sep 15, 1994 - [AD 93-24-13](https://openairdocs.org/ad/93-24-13): Trim System · Enstrom Helicopter Corporation, The 280C, 280F, 280FX and 3 more. Effective Aug 26, 1994 - [AD 94-13-03](https://openairdocs.org/ad/94-13-03): Tail Rotor Spindle Inspection · Enstrom Helicopter Corporation, The 280C, 280F, 280FX and 3 more. Effective Aug 12, 1994 - [AD 93-15-10](https://openairdocs.org/ad/93-15-10): Composite-Wrapped Main Rotor Shaft · Enstrom Helicopter Corporation, The 280, 280C, 280F and 5 more. Effective Jan 28, 1994 - [AD 90-17-03](https://openairdocs.org/ad/90-17-03): Tail Rotor Drive Shaft Couplings · Enstrom Helicopter Corporation, The 280, 280C, 280F and 5 more. Effective Sep 7, 1990 - [AD 90-17-02](https://openairdocs.org/ad/90-17-02): Tail Rotor Drive Shaft Couplings · Enstrom Helicopter Corporation, The 280, 280C, 280F and 6 more. Effective Sep 7, 1990 - [AD 90-01-06](https://openairdocs.org/ad/90-01-06): Tail Rotor Gearbox · Enstrom Helicopter Corporation, The 280, 280C, 280F and 6 more. Effective Feb 1, 1990 - [AD 82-24-01](https://openairdocs.org/ad/82-24-01): Drivebelt Clutch Mechanism · Enstrom Helicopter Corporation, The 280, 280C, 280F and 3 more. Effective Nov 30, 1982 - [AD 82-16-09](https://openairdocs.org/ad/82-16-09): Main Rotor Blade Grips · Enstrom Helicopter Corporation, The 280, 280C, 280F and 3 more. Effective Aug 4, 1982 - [AD 79-10-06 R1](https://openairdocs.org/ad/79-10-06-R1): Tail Rotor Blade Grips · Enstrom Helicopter Corporation, The 280C and F-28C. Effective Mar 19, 1982 - [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 79-02-01](https://openairdocs.org/ad/79-02-01): Turbochargers · Enstrom Helicopter Corporation, The 280C and F-28C. Effective Jan 17, 1979 - [AD 77-25-05](https://openairdocs.org/ad/77-25-05): Idle Mixture · Enstrom Helicopter Corporation, The 280C and F-28C. Effective Dec 21, 1977 - [AD 77-20-02](https://openairdocs.org/ad/77-20-02): Tail Rotor Spindle · Enstrom Helicopter Corporation, The 280, 280C, F-28 and 2 more. Effective Oct 6, 1977 - [AD 77-15-04](https://openairdocs.org/ad/77-15-04): Tail Rotor Pitch Link Assembly · Enstrom Helicopter Corporation, The 280C and F-28C. Effective Jul 26, 1977 - [AD 77-06-04](https://openairdocs.org/ad/77-06-04): Tail Rotor Assembly · Enstrom Helicopter Corporation, The 280C, F-28C, 280C and 1 more. Effective Mar 31, 1977 ### 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 2015-08-51](https://openairdocs.org/ad/2015-08-51) (historical): Main Rotor Head · Enstrom Helicopter Corporation, The 280, 280C, 280F and 8 more. Effective Jun 2, 2015 - [AD 2015-04-51](https://openairdocs.org/ad/2015-04-51) (historical): Main Rotor Head · Enstrom Helicopter Corporation, The 280, 280C, 280F and 8 more - [AD 2011-26-10](https://openairdocs.org/ad/2011-26-10) (historical): Cyclic trim system · Enstrom Helicopter Corporation, The 280C, 280F, 280FX and 6 more. Effective Jan 23, 2012 - [AD 2001-22-01](https://openairdocs.org/ad/2001-22-01) (historical): Main Rotor Shaft · Enstrom Helicopter Corporation, The 280, 280C, 280F and 8 more. Effective Nov 13, 2001 ## Information bulletins (advisory) (2 in force) - [SAIB SW-12-45](https://openairdocs.org/saib/SW-12-45): Garmin Model 400W/500W Series GPS-WAAS Navigation System. Issued Oct 3, 2012 - [SAIB SW-12-10R1](https://openairdocs.org/saib/SW-12-10R1): Fuel Level Indication. Issued Feb 3, 2012 ## NTSB investigations None matched to N221MP. ## FAA accident and incident reports None matched to N221MP. ## 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) (40) 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 (Enstrom Helicopter 280C) - [STC SR03173CH](https://openairdocs.org/stc/SR03173CH): Installation of Isolair Innovator 11 Model 3900-280 Spray System. Isolair Inc - [STC SR00063DE](https://openairdocs.org/stc/SR00063DE): Installation of Inframetrics IRTV-445G infrared imaging system. Dart Aerospace Company - [STC SH492NW](https://openairdocs.org/stc/SH492NW): Installation of cargo racks Model 100 (rectangular) or Model 101(tapered) on each side. The ENSTROM Helicopter Corporation - [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 SA11137SC](https://openairdocs.org/stc/SA11137SC): Installation of Plane-Power ALT-FLX alternator. Hartzell Engine Technologies, LLC - [STC SH1461CE](https://openairdocs.org/stc/SH1461CE): Installation of a Nite Sign Model H47B-1 Electronic Aerial Billboard. Sky Sign Inc - [STC SA02268CH](https://openairdocs.org/stc/SA02268CH): Installation of Airwolf Filter Corp. Air Oil Separator. Airwolf Filter Corporation - [STC SR02124SE](https://openairdocs.org/stc/SR02124SE): Installation functionality. of Data Garmin Required: transponders: (1) Garmin GTX Master 345/345R Drawing with List ADS-B (MDL), Out and In 005-00734-A4, functionality;. Garmin International Inc - [STC SR00359BO](https://openairdocs.org/stc/SR00359BO): Installation of Parmetheus Plus LED PAR36 and PAR46 taxi and landing lights. Whelen Aerospace Technologies - [STC SR00568NY](https://openairdocs.org/stc/SR00568NY): Installation of remote mounted oil filter, model AFC-500 or AFC-600, and kit AFC-K014. Airwolf Filter Corporation - [STC SA2586NM](https://openairdocs.org/stc/SA2586NM): Installation of J.P. Instruments temperature monitoring systems. J P Instruments - [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 SR03465CH](https://openairdocs.org/stc/SR03465CH): Install Airwolf Aerospace, LLC Tension-Torsion Strap Assemblies, P/N AA-ECD-084-280, or AA-ECD-084-480. Airwolf Aerospace LLC - [STC SR03520NY](https://openairdocs.org/stc/SR03520NY): Installation of Rotor Head Cover. Spitfire Aerospace, 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 SH4061NM](https://openairdocs.org/stc/SH4061NM): Installation of Pneumatic Door Actuators. Air Comm Corporation - [STC SR03353CH](https://openairdocs.org/stc/SR03353CH): Installation of Aspen Avionics Evolution Primary and Multi-Functional Flight Displays. AspenSTC Inc - [STC SR02232LA](https://openairdocs.org/stc/SR02232LA): Installation of Garmin Model 400W / 500W Series GPS-WAAS Navigation System. Garmin AT 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 SR01430LA](https://openairdocs.org/stc/SR01430LA): Installation of Stainless Steel Skid shoes. Papas Gary Los Angeles Laboratories 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 SA00061LA](https://openairdocs.org/stc/SA00061LA): Installation of JPI digital tachometer. J P Instruments - [STC SA00238SE](https://openairdocs.org/stc/SA00238SE): Installation of Aviation Development Corporation's sump mounted chip detector. Aviation Development Corporation - [STC SR00179DE](https://openairdocs.org/stc/SR00179DE): Installation of Oilamatic preoiler system. Oilamatic 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 SA2867NM](https://openairdocs.org/stc/SA2867NM): Installation of Turboplus/ Electronics Int'l digital temperature gauges. Turboplus, Inc. Lists 280 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 SH592GL](https://openairdocs.org/stc/SH592GL): Install Tayburn Electronics microwave antennae, microwave transmitter, and microwave receiver to landing gear skid. Airborne Microwave, Inc - [STC SA2386SW](https://openairdocs.org/stc/SA2386SW): Installation of S.A.F.E., EGT, CHT Systems. Avicon Development Corporation - [STC SA2350NM](https://openairdocs.org/stc/SA2350NM) (historical): Installation of Electronics International Inc digital carburetor/outside air temperature gauges listed on the attached continuation sheet and the associated accessories. Electronics International ## Earlier aircraft with N221MP The FAA can reassign an N-number once a registration is cancelled. These aircraft carried N221MP before. - [Cancelled 1994-09-02](https://openairdocs.org/deregistered/N221MP-1994-09-02): Boeing 747-283B, S/N 20120. Owner: [Aircraft Instrument & Radio Co Inc](https://openairdocs.org/faa-owner/AIRCRAFT%20INSTRUMENT%20%26%20RADIO%20CO%20INC), [Wichita, KS](https://openairdocs.org/faa-place/KS/Wichita) ## Related - Other Enstrom Helicopter 280C aircraft: https://openairdocs.org/model/enstrom-helicopter-280c/aircraft.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.