SA5846NMFuel systems
Installation of wing tank flexible fuel cells.
FAA holder: Aerosport Fuel Cells, LLC
Aircraft STC directory
Textron Aviation 421 STCs
The Jun 30, 2026 FAA DRS snapshot contains 9 selected supplemental type certificates with status Current whose public applicability data names the Textron Aviation 421. Use it to identify modification scope and recorded holders—not to determine serial-number effectivity, compatibility, installation approval, or commercial availability.
9
listed Current at snapshot
7
holder directories
5
modification categories
Feb 17, 2026
latest recorded revision
Modification demand surface
Other aircraft modifications3
Fuel systems2
Flight controls2
Aircraft structures1
Avionics1
Recently revised 421 STCs
Showing the 9 most recently revised records. Each entry links to the FAA source and separates public approval data from private commercial claims.
View record
SA197GLOther aircraft modifications
Install Cleveland conversion kit P/N 199-76.
FAA holder: Kaman Corporation Aircraft Wheel and Brake LLC
SA03317CHOther aircraft modifications
Installation of Max-Viz EVS-600 Enhanced Vision System.
FAA holder: PECO Inc
SA09751DSFlight controls
Installation of an S-TEC 01326 Digital Flight Control System (DFCS).
FAA holder: S-TEC Corporation
SA18NWFlight controls
Installation of Fowler flaps, flap actuated drooped ailerons, flap actuated elevator trim and anti- servo rudder trim tab.
FAA holder: Sierra Industries Inc
SA09774ACOther aircraft modifications
Replacement of certain Goodrich pneumatic deicer boots.
FAA holder: Goodrich Corp.
SA02239SEAircraft structures
Installation of a Skymech rear spar replacement kit.
FAA holder: Skymech LLC
SA574NWFuel systems
Installation of forward facing white lights, (100 Watts) and clear plastic wing tip tank nose cone and associated systems.
FAA holder: Knots 2U Ltd.
SA03527ATAvionics
Installation of an Avidyne EXP5000 Primary Flight Display (PFD).
FAA holder: Star Aviation