SA02254AKOther aircraft modifications
Installation of "Single Screen", "2 or 3 Screen", "Dual Screen", or "4 or 6 screen".
FAA holder: Genesys Aerosystems Inc.
Aircraft STC directory
Cessna Aircraft 421B STCs
The Jun 30, 2026 FAA DRS snapshot contains 43 selected supplemental type certificates with status Current whose public applicability data names the Cessna Aircraft 421B. Use it to identify modification scope and recorded holders—not to determine serial-number effectivity, compatibility, installation approval, or commercial availability.
43
listed Current at snapshot
28
holder directories
9
modification categories
Jun 16, 2022
latest recorded revision
Modification demand surface
Other aircraft modifications23
Engine and powerplant5
Cargo and special mission4
Fuel systems3
Cabin and interiors3
Avionics2
Electrical systems1
Aircraft structures1
Flight controls1
Recorded holders
RAM Aircraft Limited Partnership4Aviation Fabricators Inc3Air Comm Corporation2SMR Technologies Inc2OCR Aviation2Eaglejet Aviation Inc.2Genesys Aerosystems Inc.1Sandel Avionics LLC1LifePort LLC1Spectrum Aeromed LLC dba Spectrum Aeromed1Griggs Aircraft Refinishing LLC1Paul/ Lanna Egan LLC1Spoilers Inc1Bell Helicopter Textron Inc.1D'Shannon Products Ltd.1P2 Incorporated1Snaky Creek Enterprises LLC dba Spectrum Aeromed1M-20 Oil Separators LLC1Honeywell International Inc1Precise Flight Inc1
Recently revised 421B STCs
Showing the 43 most recently revised records. Each entry links to the FAA source and separates public approval data from private commercial claims.
View record
SA4270SWEngine and powerplant
Mount collision avoidance lights in engine nacelle.
FAA holder: Johnson Aviation Products
SA01316LAAvionics
Installation of Sandel Avionics Terrain Awareness and Warning System.
FAA holder: Sandel Avionics LLC
SA2091WEOther aircraft modifications
Installation of air conditioning system.
FAA holder: Air Comm Corporation
SA8RMOther aircraft modifications
Installation of a vapor cycle air-conditioning system.
FAA holder: Air Comm Corporation
SA00057SEElectrical systems
Installation of emergency medical stretcher, oxygen, and electrical systems.
FAA holder: LifePort LLC
SA00571SEOther aircraft modifications
Replacement of certain BF Goodrich pneumatic deicer boots.
FAA holder: SMR Technologies Inc
SA01213CHCargo and special mission
Install air ambulance conversion in accordance with Spectrum Aeromed Inc. Drawings as listed on AML SA01213CH, or later FAA approved revision.
FAA holder: Spectrum Aeromed LLC dba Spectrum Aeromed
SA01935LAOther aircraft modifications
Installation of external aft body strakes.
FAA holder: Aircraft Performance Modifications
SA2514CEEngine and powerplant
Installation of wing nacelle locker tanks and fuel transfer system.
FAA holder: Griggs Aircraft Refinishing LLC
SA1048GLCargo and special mission
Install Egan Aviation air ambulance stretcher P/N 125 using Installation Kit P/N 801.
FAA holder: Paul/ Lanna Egan LLC
SA02003NYOther aircraft modifications
Replacement of certain Goodrich pneumatic deicer boots.
FAA holder: B/E Aerospace Inc. dba SMR Technologies, Inc.
SA1146SOOther aircraft modifications
Installation of nose cone erosion cap.
FAA holder: Bell Helicopter Textron Inc.
SA5167NMEngine and powerplant
Installation of vortex generators on the wings and vertical stabilizer and strakes on outboard side of engine nacelles.
FAA holder: D'Shannon Products Ltd.
SA00103WIOther aircraft modifications
Installation of a heated windshield panel.
FAA holder: Aviation Fabricators Inc
SA02110CH (PAGE 2)Other aircraft modifications
Installation of a Time Trac Data Recorder.
FAA holder: P2 Incorporated
SA1535GLCargo and special mission
Install air ambulance conversion.
FAA holder: Snaky Creek Enterprises LLC dba Spectrum Aeromed
SA5796SW-DFuel systems
Installation of Alcor Tru-Flow indicating system, or SDI Hoskins fuel flow indicating system, or Silver Instruments Fueltron fuel flow indicating system.
FAA holder: RAM Aircraft Limited Partnership
SA02033AT (PAGE 6)Engine and powerplant
Modification to install an air-oil separator to prevent oil from being aspirated from the engine breather line (47J series w stc's SH4-235SW, SH4-826SW or SH479SW).
FAA holder: M-20 Oil Separators LLC
SA568EAOther aircraft modifications
Installation of Grimes Manufacturing Company three light strobe kit P/N 34-0107-1.
FAA holder: Honeywell International Inc.
SA1034CEFuel systems
Installation of 50-gallon fuel tank in nose baggage compartment. Limited to installation on model 421B, serial number 421B0602 ONLY.
FAA holder: Eaglejet Aviation Inc.
SA1035CECabin and interiors
Install openable window aft of cabin door.
FAA holder: Eaglejet Aviation Inc.
SA00229BOOther aircraft modifications
Descriptive data pertaining to this modification is considered inadequate for duplication in other aircraft. This approval is limited to the installation made in Cessna Model 421B, Serial Number 421B0507. Approval for operation in Known Icing Conditions.
FAA holder: Maine Aviation Management Inc
SA10361SCOther aircraft modifications
Installation of Hartzell Model PHC-C3YD-2UF/FC9587DB-7 or Model PHC-C3YD-2UF/FC9587D-7 propellers.
FAA holder: RAM Aircraft Limited Partnership
SA01591SEFlight controls
Fabrication of Spoilers, Inc. Model SP1000UG spoiler system.
FAA holder: TRM Avionics Logistics Inc
SA3522NMOther aircraft modifications
Installation of Precise flight series 400 speedbrake system.
FAA holder: Precise Flight Inc
SA00161BO (2 OF 3Avionics
Installation of Avidyne Corporation FlightMax 700-00007-( ) EX500 Multi-Function Display.
FAA holder: Avidyne Corporation
SA02217AK (3 OF 5Other aircraft modifications
Installation of Garmin AT Model GDL90 UAT Data Link System, in accordance with Garmin AT, Inc., GDL 90 UAT Master Data List, P/N 560-0278-01, Revision A, dated November 12, 2004, or later FAA approved revision.
FAA holder: Garmin AT Inc.
SA2650NMOther aircraft modifications
Cockpit Sun Visor Installation.
FAA holder: Rosen Sunvisor Systems LLC
SA00948CHOther aircraft modifications
Installation of various de-icer wire harnesses. (E90 modified by STC SA3593NM, F90 modified by STC SA4131NM, B200 modified by STC SA2698NM-S, DHC-6 Series modified by STC SA3532NM).
FAA holder: SMR Technologies Inc
SA2715CECabin and interiors
Installation of single place composite commuter seats on the seat rails per Aviation Fabricators Drawing list No. AF-130 stamped "FAA Approved" May 2, 1991, or later FAA approved revision.
FAA holder: Aviation Fabricators Inc
SA2716CECabin and interiors
Installation of double composite commuter seats on the seat rails per Aviation Fabricators Drawing List No. AF-130 stamped "FAA Approved" May 2, 1991, or later FAA approved revision.
FAA holder: Aviation Fabricators Inc
SA1BOOther aircraft modifications
Installation of Safeway Model7009-1 deicer kit.
FAA holder: Goodrich Corp.
SA802NEOther aircraft modifications
Installation of Cessna SK310-114-0 electric windshield heated panel installation kit.
FAA holder: Aviation Management Services, Inc
SA09544SCOther aircraft modifications
Installation of a wastegate in-line oil strainer.
FAA holder: RAM Aircraft Limited Partnership
SA5878SWOther aircraft modifications
Installation of range-marked EGT, CHT, oil temperature, and pressure gauges.
FAA holder: RAM Aircraft Limited Partnership
SA01117ATOther aircraft modifications
Installation of Composite Spinner.
FAA holder: TCB Composite Co.
SA3003WEOther aircraft modifications
Installation of recognition light assembly on horizontal stabilizer.
FAA holder: DeVore Aviation Corporation of America, a New Mexico Corporation