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Aircraft STC directory

Learjet 35A (C-21A) STCs

The Jun 30, 2026 FAA DRS snapshot contains 158 selected supplemental type certificates with status Current whose public applicability data names the Learjet 35A (C-21A). Use it to identify modification scope and recorded holders—not to determine serial-number effectivity, compatibility, installation approval, or commercial availability.

158
listed Current at snapshot
47
holder directories
12
modification categories
Sep 15, 2025
latest recorded revision

Modification demand surface

Other aircraft modifications67Avionics35Cabin and interiors11Safety and emergency equipment11Aircraft connectivity9Cargo and special mission6Electrical systems4Aircraft structures4Engine and powerplant4Fuel systems3Landing gear and brakes2Flight controls2

Recorded holders

Learjet Inc.31Avcon Industries Inc12Duncan Aviation Inc9Butler National Corporation7Stevens Aviation Inc.7Phoenix Air Group Inc.5West Star Aviation5Royal Air Inc4Global Aviation Technologies4AeroMech Incorporated4Sabreliner Aviation LLC4Symetric Industries, DBA Extant Aerospace3Lee Aerospace Inc.3Global Aviation Tech LLC2Chippewa Aerospace, Inc.2Peregrine2Summit Aviation Inc.2Blackhawk Aerospace Technologies Inc.2West Star Aviation Inc2Insight Instrument Corporation2

Recently revised 35A (C-21A) STCs

Showing the 100 most recently revised records. Each entry links to the FAA source and separates public approval data from private commercial claims.

ST04393CHAircraft connectivity

Avionics upgrade installation of a Garmin GTN (TM) 750 Touchscreen Navigator interfaced to existing pilot side instruments and existing FC-200 or FC-530/-550 Autopilot and added GWX (TM) 70 Weather Radar. The Garmin GTN (TM) 750 GPS is paired with the added GTX (TM) 345R (or GTX 33/33D) Transponders for Automatic Broadcast Surveillance (ADS-B) OUT and ADS-B IN (GDL-88) capability with wireless download connectivity utilizing Garmin Connext®. Optional second Garmin GTN (TM) 650/750 interfaced to existing copilot side instruments only.

FAA holder: Royal Air Inc.

View record
ST04447CHAircraft connectivity

Installation of Garmin GTS (TM) 8000 TCAS/ACAS II Traffic Surveillance system, dual GTX (TM) 3000 Mode-S Extended Squitter Transponders and GDL® 88 receiver for a complete ADS-B In/Out capability and a Flight Stream 210 for wireless download connectivity using Garmin Connext®. Installation in accordance with Royal Air Master Document List No. RACB-MDL-3000, Revision A, dated January 06, 2020, or later FAA approved revision.

FAA holder: Royal Air Inc

View record