# N21988: 2001 Buck Robin F BUCKSTON B2+2 - Status: Valid registration - Airframe: [Buck Robin F BUCKSTON B2+2](https://openairdocs.org/model/buck-robin-f-buckston-b2-plus-2) (registry code 05610DF, 4 seats) - Engine: [Franklin 6A4165 series](https://openairdocs.org/engine/franklin-6a4165-series) (registry code 27025) - Data sheets: [TCDS E-238](https://openairdocs.org/tcds/E-238) (Franklin Sp. z.o.o.) (OpenAirDocs) - Serial number: 1 - Year built: 2001 - Type: Fixed wing single engine - Engine type: Reciprocating - Airworthiness: Experimental, amateur built - Airworthiness date: September 19, 2001 - Certificate issued: May 8, 2000 - Expires: April 30, 2027 - Mode S code: A1DE82 - Registered owner: [Buck Robin F](https://openairdocs.org/faa-owner/BUCK%20ROBIN%20F) - Location: [Kent, WA](https://openairdocs.org/faa-place/WA/Kent) - Owner type: Individual - Owner's area on the map: 47.3635° N, 122.1183° W: Placed by OpenAirDocs at the center of ZIP code 98042, 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=21988 - Page: https://openairdocs.org/aircraft/N21988 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 6A4165 model are included. ## ADs that may apply (OpenAirDocs): 4 in force ### Matched by airframe (Buck Robin F BUCKSTON B2+2) None in force. ### Matched by engine (Franklin 6A4165 series) - [AD 96-02-04](https://openairdocs.org/ad/96-02-04): 80 Octane Avgas · Wytwornia Sprzetu Komunikacyjnego 6A4-150-B3 and 6A4-165-B3. Effective Feb 13, 1996 - [AD 63-22-03](https://openairdocs.org/ad/63-22-03): Carburetors · Continental Motors GO-300-A, GO-300-B, GO-300-C and 143 more. Effective Dec 2, 1963 - [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 51-15-02](https://openairdocs.org/ad/51-15-02): Crankcase · Wytwornia Sprzetu Komunikacyjnego 6A4-165-B3 ## Information bulletins (advisory) None matched. ## NTSB investigations None matched to N21988. ## FAA accident and incident reports None matched to N21988. ## 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) (12) 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 6A4165 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 6A4-165-B3 - [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 6A4-165-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 6A4-165-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 6A4-165-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 6A4-165-B3 - [STC SE4178NM](https://openairdocs.org/stc/SE4178NM): Installation of oil filter kit. Franklin Aircraft Engines Inc. Lists 6A4-165-B3 - [STC SE3331NM](https://openairdocs.org/stc/SE3331NM): Lycoming valve cover gasket. Real Gaskets Tennessee. Lists 6A4-165-B4 - [STC SE110CH](https://openairdocs.org/stc/SE110CH): Installation of Slick Model 6399 magnetos. Champion Aerospace LLC. Lists 6A4-165-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 6A4-165-B4 - [STC SE1696GL](https://openairdocs.org/stc/SE1696GL): Installation of nose seal retainer. Skaggs Robert G. Lists 6A4-165-B3 - [STC SE2127CE](https://openairdocs.org/stc/SE2127CE): 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 6A4-165-B3 - [STC SE4-1192](https://openairdocs.org/stc/SE4-1192): Adapter to permit Bendix Scintilla magneto installation, Type SF6LN-8, and modification of carburetor- manifold adapter box. Van De Water Devel Co. Lists 6A4-165-B3 ## Earlier aircraft with N21988 The FAA can reassign an N-number once a registration is cancelled. These aircraft carried N21988 before. - [Cancelled 1996-09-03](https://openairdocs.org/deregistered/N21988-1996-09-03): Cessna 150L, S/N 15074592. Exported to Switzerland. Owner: [Epp David R](https://openairdocs.org/faa-owner/EPP%20DAVID%20R), [New Port Richey, FL](https://openairdocs.org/faa-place/FL/New%20Port%20Richey) - [Cancelled 1951-06-15](https://openairdocs.org/deregistered/N21988-1951-06-15): Porterfield CP-50, S/N 571. Owner: [Naylor Robert M](https://openairdocs.org/faa-owner/NAYLOR%20ROBERT%20M), [Dearborn, MI](https://openairdocs.org/faa-place/MI/Dearborn) ## Related - Other Buck Robin F BUCKSTON B2+2 aircraft: https://openairdocs.org/model/buck-robin-f-buckston-b2-plus-2/aircraft.md - The Franklin 6A4165 series engine: https://openairdocs.org/engine/franklin-6a4165-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.