# Learjet 55C

- Type: Aircraft model (FAA registry)
- Registry code: 5170708
- Manufacturer (registry): LEARJET INC
- Model: 55C
- Aircraft type: Fixed wing multi engine
- Category: Airplane
- Engines: 2 · Turbo-fan
- Seats: 13
- Weight class: 12,500 to 19,999 lb
- Certification: Type certificated
- Data sheet: [TCDS A10CE](https://openairdocs.org/tcds/A10CE) (OpenAirDocs)
- Holder: Learjet Inc.
- Registered aircraft: 0
- Page: https://openairdocs.org/model/learjet-55c

Model codes come from the FAA registry's reference file. ADs are matched to them by model name and maker.

## ADs that may apply (OpenAirDocs)

Matched to this model by model name and maker. Each AD's applicability may narrow it by serial number, part number or equipment.

- [AD 2022-05-01](https://openairdocs.org/ad/2022-05-01): Spoilers · Learjet 35, 35A (C-21A), 36 and 5 more. Effective Mar 9, 2022
- [AD 2018-19-04](https://openairdocs.org/ad/2018-19-04): TE Flap Control System · Learjet 28, 29, 31 and 9 more. Effective Oct 23, 2018
- [AD 2009-03-01](https://openairdocs.org/ad/2009-03-01): Lavatory light assembly · Learjet 55, 55B and 55C. Effective Mar 5, 2009
- [AD 2007-17-17](https://openairdocs.org/ad/2007-17-17): Unsealed gaps on the pylon side of the engine firewall · Learjet 31, 31A, 35 and 7 more. Effective Oct 2, 2007
- [AD 2007-04-18](https://openairdocs.org/ad/2007-04-18): Left- and right-hand standby fuel pump switches · Learjet 23, 24, 24A and 25 more. Effective Mar 23, 2007
- [AD 2001-12-02](https://openairdocs.org/ad/2001-12-02): Brake Valve · Learjet 55, 55B, 55C and 1 more. Effective Jul 18, 2001
- [AD 2001-07-11](https://openairdocs.org/ad/2001-07-11): Main Landing Gear Tires · Learjet 23, 24, 24A and 25 more. Effective May 1, 2001
- [AD 95-19-04 R1 RES](https://openairdocs.org/ad/95-19-04-R1-RES): Omega Navigation System · Learjet 35, 35A (C-21A), 36 and 4 more. Effective Mar 27, 2000
- [AD 99-16-03](https://openairdocs.org/ad/99-16-03): Horizontal Stabilizer Anti-Ice System · Learjet 23, 24, 24A and 22 more. Effective Sep 7, 1999
- [AD 95-20-03](https://openairdocs.org/ad/95-20-03): Airplane Flight Manual (AFM) - Altitude Limitations · Learjet 24, 24A, 24B and 24 more. Effective Nov 2, 1995
- [AD 93-24-10](https://openairdocs.org/ad/93-24-10): Generator Wiring · Learjet 55, 55B and 55C. Effective Jan 18, 1994
- [AD 91-03-08](https://openairdocs.org/ad/91-03-08): Fluorescent Lighting Systems · Learjet 31, 35, 35A (C-21A) and 5 more. Effective Feb 12, 1991
- [AD 89-12-01](https://openairdocs.org/ad/89-12-01): Drag Chute Riser · Learjet 24, 24A, 24B and 22 more. Effective Jul 3, 1989
- [AD 87-04-06](https://openairdocs.org/ad/87-04-06): Autopilot/Flight Director · Learjet 35, 35A (C-21A), 36 and 4 more. Effective Mar 9, 1987
- [AD 87-02-06](https://openairdocs.org/ad/87-02-06): Engine Mounts · Learjet 35, 35A (C-21A), 36 and 4 more. Effective Feb 6, 1987
- [AD 86-22-05](https://openairdocs.org/ad/86-22-05): Flap Sector Mounting Brackets Inspection · Learjet 23, 24, 24A and 23 more. Effective Nov 10, 1986
- [AD 84-19-06](https://openairdocs.org/ad/84-19-06): Tab Control System · Learjet 24, 24A, 24B and 22 more. Effective Oct 22, 1984

Historical (superseded or no longer in force):

- [AD 95-19-04](https://openairdocs.org/ad/95-19-04) (historical): Omega Navigation System · Learjet 35, 35A (C-21A), 36 and 4 more. Effective Oct 12, 1995

## Information bulletins (advisory) (2)

- [SAIB 2026-07](https://openairdocs.org/saib/2026-07): MAIN LANDING GEAR ATTACH SECTION, Trunnion Pins. Issued Mar 19, 2026
- [SAIB NM-16-24](https://openairdocs.org/saib/NM-16-24): Fuselage: Main Plate/Skin. Issued Sep 15, 2016

## Registered aircraft

None registered with this model now.

## NTSB investigations

None matched to aircraft with this model.

## FAA accident and incident reports

None matched to aircraft with this model.

## Service difficulty reports (16)

As reported by operators and repair stations, by the model named in the report.

- [SDR CJPA202001210001](https://openairdocs.org/sdr/CJPA202001210001), Jan 20, 2020: HYDRAULIC LINE. SPLIT. 20 MINUTES INTO CRUISE AT FL380 PIC NOTICED A LOW HYDRAULIC PRESSURE AMBER LIGHT ON THE ANNUNCIATOR. A QUICK LOOK AT THE HYDRAULIC PRESSURE GAUGE SHOWED ZERO PR
- [SDR 2020F00047](https://openairdocs.org/sdr/2020F00047), Nov 14, 2019: TIRE. FAILED. DURING A NORMAL TAKEOFF ROLL ON 19L AT KLAS ONE OF THE LEFT MAIN TIRES BLEW DUE TO A SUSPECTED ENCOUNTER WITH FOD AT APPROXIMATELY 105 KNOTS WITH A V1 TAKEOFF D
- [SDR 2017F00178](https://openairdocs.org/sdr/2017F00178), Sep 20, 2017: FLOW VALVE. FAULTY. ON DEPARTING KCXY "CABIN ALT" LIGHT ILLUMINATED PASSING THROUGH 10,000 FEET. CAPTAIN ELECTED TO LAND AT KMDT INSTEAD OF THE FILED DESTINATION (FXE).
- [SDR A8JA201606040022](https://openairdocs.org/sdr/A8JA201606040022), Jun 4, 2016: CIRCUIT BREAKER. TRIPPED. DURING APPROACH, FLIGHT CREW HEARD A POP AND EXPERIENCED A LOSS OF FLIGHT INSTRUMENTS AND RADIOS. PIC REPORTED ALL EFIS SCREENS, ALTIMETERS, AIRSPEED INDICATORS
- [SDR 2016FA0000016](https://openairdocs.org/sdr/2016FA0000016), Dec 21, 2015: STRUT. LEAKING. UPON REACHING CRUISE ALTITUDE, THE GEAR UNSAFE INDICATOR ILLUMINATED. UPON INSPECTION OF THE NLG IT, WAS DISCOVERED THAT THE NITROGEN/FLUID DEPLETED THE PISTON 
- [SDR 2011FA0000457](https://openairdocs.org/sdr/2011FA0000457), Jul 10, 2011: WHEEL HALF. FAILED. PRIOR TO LIFTOFF, THE OUTER RIM OF THE RIGHT INBD MAIN WHEEL SEPARATED FROM THE WHEEL ASSEMBLY. THE FLIGHT CREW WAS NOTIFIED BY RADIO THAT A "TIRE BLEW" DURING 
- [SDR OZCA11082009](https://openairdocs.org/sdr/OZCA11082009), Nov 8, 2009: VALVE. DEFECTIVE. DURING A REPOSITIONING FLIGHT FROM FLL TO ORL AFTER DEPARTURE THE CAPTAIN NOTICED SMOKE FORMING IN THE CABIN AND RETURNED TO FLL FOR AN UNEVENTFUL LANDING. MAIN
- [SDR A8J2006F00001](https://openairdocs.org/sdr/A8J2006F00001), Oct 30, 2006: HINGE. FAILED. AIRCRAFT DEPARTED, DURING CLIMB AT ABOUT 13,000 FT THE CREW NOTICED A STRANGE AIRFLOW NOISE AS IF A GEAR DOOR WAS OPEN, ALL INSTRUMENT INDICATIONS WERE GOOD. (3
- [SDR CIEA200500011](https://openairdocs.org/sdr/CIEA200500011), Jul 24, 2005: LATCH. OUT OF ADJUST. AFTER TAKEOFF, THE LEFT THRUST REVERSER LIGHT FLASHED ON THEN WENT OUT. THE PILOT ELECTED TO LAND AND HAVE IT LOOKED AT. THERE WAS NO EVIDENCE THAT THERE WAS A 
- [SDR 2000ZZZX583](https://openairdocs.org/sdr/2000ZZZX583), Feb 7, 2000: RIVET. MISINSTALLED. SIX RIVETS MISSING FROM RT FUSELAGE BETWEEN MIDDLE AND AFT WING ATTACH POINTS. BS 401.92 AND BS 410.30. THESE RIVETS DO NOT GO THROUGH THE PRESSURE VESSEL, BUT 
- [SDR 99ZZZX3497](https://openairdocs.org/sdr/99ZZZX3497), Jul 29, 1999: FITING. FAILED. AFTER TAKEOFF DURING GEAR REATRACTION, LOUD NOISE WAS HEARD IN CABIN. ALL SYSTEMS APPEARED NORMAL. UPON LANDING CREW FOUND RIGHT OUTBOARD GEAR DOOR ATTACH FITTI
- [SDR NI2R032L](https://openairdocs.org/sdr/NI2R032L), Feb 1, 1998: LATCH PIN ARM. CRACKED. PERFORMED EDDY CURRENT TEST PER LEAR NDT MANUAL PART 3 52-10-01. DETECTED LINEAR INDICATION AT AREA 'F' AT APPROX 4 O'CLOCK POSITION. REFERENCE ST LOUIS TEST LA
- [SDR 97ZZZX3504](https://openairdocs.org/sdr/97ZZZX3504), Jul 16, 1997: COUPLING. FAILED. CLAMP ON COUPLING OPENED AND FELL OFF. COUPLING LOCATED IN FUEL SUPPLY LINE JUST BELOW LEFT FUEL FILTER IN TAIL CONE. AIRCRAFT CREW NOTICED DECREASING FUEL QUAN
- [SDR 95ZZZX5253](https://openairdocs.org/sdr/95ZZZX5253), Sep 7, 1995: CLAMP. DEFECTIVE. INSPECTION FOUND FUEL FILTER CLAMP FAULTY. THIS IS FOLLOW-UP ON PREVIOUSLY SUBMITTED REPORT. SUBMITTER RECOMMENDED THAT CLAMPS UTILIZED IN AREAS SUBJECT TO VIBR
- [SDR 95ZZZX3690](https://openairdocs.org/sdr/95ZZZX3690), Jul 7, 1995: PUMP. SHAFT STRIPPED. NR 1 ENGINE DRIVEN HYDRUALIC PUMP SHAFT WAS COMPLETELY STRIPPED OF ALL GEAR MATING SURFACE AREA RESULTING IN NO HYDRAULIC OUTPUT FROM THAT ENGINE. FOUND ON INIT
- [SDR 95ZZZX3596](https://openairdocs.org/sdr/95ZZZX3596), Jul 1, 1995: CLAMP. OPENED. MAIN FUEL LINE SUPPLY FROM RT WING TO RT ENGINE CLAMP OPENED UP WHILE AIRCRAFT WAS IN FLIGHT CAUSING FUEL LOSS. FUEL IMBALANCE AND RIGHT ENGINE FLAME-OUT AFTER 

## STCs that may be installed (OpenAirDocs) (65, first 50)

Approved for this model: the STC's model list names it on its data sheet, or a series that includes it. In force first, then newest. The registry doesn't record which STCs an aircraft has.

- [STC ST01305WI-D](https://openairdocs.org/stc/ST01305WI-D): Modification of a Collins ALT-50A or ALT-55B Radio Altimeter system installation to a Collins ALT-1000 or ALT-4000 Radio Altimeter system installation in accordance with Collins Drawing Index as listed on AML No. ST01305WI-D, Revision -, or later FAA approved revision. Rockwell Collins Inc
- [STC SA2622NM](https://openairdocs.org/stc/SA2622NM): Installation of Precise Flight Pulselite Control Unit in landing/taxi system. (767-200 B17) (DHC-8 101). Precise Flight Inc
- [STC ST03885AT](https://openairdocs.org/stc/ST03885AT): Installation of an Avionica, Inc. avCM Cellular Module. Aircraft Systems and Manufacturing Inc
- [STC ST12087CH](https://openairdocs.org/stc/ST12087CH): Installation replacement Cabin/Cockpit Handheld Fire Extinguishers. Avcon Industries Inc
- [STC ST02472AT](https://openairdocs.org/stc/ST02472AT): Installation of a mini Quick Access Recorder (QAR) model MKI, MKII, or MKIII. Aircraft Systems and Manufacturing Inc
- [STC ST01936WI](https://openairdocs.org/stc/ST01936WI): Installation of LED lights. AeroLED's Holdings LLC
- [STC ST01138DE](https://openairdocs.org/stc/ST01138DE): Installation of MidContinent MD23 standby altimeter and/or attitude indicators. Butler National Corporation
- [STC ST03424CH](https://openairdocs.org/stc/ST03424CH): Certification of Automatic Dependent Surveillance - Broadcast (ADS-B) Out System with Rockwell Collins TDR-94/-94D Transponders. CMD Flight Solutions LLC
- [STC ST04393CH](https://openairdocs.org/stc/ST04393CH): 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. Royal Air Inc
- [STC ST04575AT](https://openairdocs.org/stc/ST04575AT): Installation of the Rockwell Collins ALT-1000+/ -4000+ with 5G Filtering. Chippewa Aerospace Inc
- [STC ST01070DE](https://openairdocs.org/stc/ST01070DE): Installation of the Curtiss-Wright Fortress Flight Data Recorder (with Cockpit Voice Recorder). Peregrine
- [STC ST00098IB](https://openairdocs.org/stc/ST00098IB): Introduction of ADS-B Out. STC Twenty One Limited
- [STC ST02004WI](https://openairdocs.org/stc/ST02004WI): Installation of the Garmin GI-275 Instantaneous Vertical Speed Indicators (IVSI). Peregrine
- [STC ST04208NY](https://openairdocs.org/stc/ST04208NY): Installation of LAI Windowshields. Lee Aerospace Inc
- [STC ST04177AT](https://openairdocs.org/stc/ST04177AT): Installation of a Talon Aerospace LED Replacement General Purpose Lamps. Aaxico Technical Services Inc
- [STC ST11069SC](https://openairdocs.org/stc/ST11069SC): Installation of Sky Connect Forte'/AirMail Wi-Fi (Wireless) communication system. Honeywell International Inc
- [STC ST04447CH](https://openairdocs.org/stc/ST04447CH): 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. Royal Air Inc
- [STC ST02635LA](https://openairdocs.org/stc/ST02635LA): Modification to replace the existing Mode S Transponder system with the ACSS NXT-600 Mode S Transponder with ADS-B Out. Aviation Communication and Surveillance Systems (ACSS) LLC
- [STC SA01452CH](https://openairdocs.org/stc/SA01452CH): Installation of an air ambulance conversion kit. Med-Pac Inc
- [STC ST00882DE](https://openairdocs.org/stc/ST00882DE): Installation of Becker Avionics BXT6553 transponder. Peregrine
- [STC SA00276SE](https://openairdocs.org/stc/SA00276SE): Installation of emergency medical stretcher, oxygen, and electrical systems. LifePort, LLC
- [STC ST00276SE](https://openairdocs.org/stc/ST00276SE): Installation of emergency medical stretcher, oxygen, and electrical systems. LifePort, LLC
- [STC ST04340NY](https://openairdocs.org/stc/ST04340NY): Installation of TCAS 7.1 (ACAS II) upgrade of Prior Existing TCAS 7.0. Scandinavian Avionics Design ApS
- [STC ST00835DE](https://openairdocs.org/stc/ST00835DE): Installation of Automatic Dependent Surveillance - Broadcast (ADS-B) Out and In functionality using the Garmin GTX 335R and GTX 345R Transponders plus qualified position sensor. Peregrine
- [STC SA4999NM](https://openairdocs.org/stc/SA4999NM): Installation of lifeport patient loading and support system. LifePort LLC
- [STC SA01213CH](https://openairdocs.org/stc/SA01213CH): Install air ambulance conversion in accordance with Spectrum Aeromed Inc. Drawings as listed on AML SA01213CH, or later FAA approved revision. Spectrum Aeromed LLC dba Spectrum Aeromed
- [STC ST00790DE](https://openairdocs.org/stc/ST00790DE): Installation of BendixKing CAS 67B Traffic Alert and Collision Avoidance System (TCAS) II Version 7.1. Peregrine
- [STC ST00347BO](https://openairdocs.org/stc/ST00347BO): Modification to upgrade a BendixKing CAS 67A TCAS II system to CAS 67B TCAS II Change 7.1. Pro Star Aviation, LLC
- [STC ST00373BO](https://openairdocs.org/stc/ST00373BO): Installation of Rockwell Collins TDR-94D Transponders with ADS-B Out. Pro Star Aviation, LLC
- [STC ST11071SC](https://openairdocs.org/stc/ST11071SC): Demonstration of aircraft critical equipment and antenna systems tolerance of radio frequency interference (RFI) from intentional or spurious transmissions from certain Portable Electronic Devices (PEDs). Liberty Partners Inc
- [STC ST03776NY](https://openairdocs.org/stc/ST03776NY): Modification to upgrade existing Rockwell Collins TCAS (Model: TTR-920, TTR-921, and TTR-4000) at VERSION 7.0 to Rockwell Collins TCAS (Model: TTR-921, TTR-4000, and TTR-4100) at VERSION 7.1 (ACAS II). Scandinavian Avionics Design ApS
- [STC ST00881WI-D](https://openairdocs.org/stc/ST00881WI-D): Modification of a TCAS II system installation to Change 7.0 or Change 7.1. Rockwell Collins Inc
- [STC ST04238AT](https://openairdocs.org/stc/ST04238AT): Upgrade of Honeywell Traffic Collision Avoidance Systems II (TCAS II) Processor Software from TCAS II Version 7.0 to TCAS II Version 7.1. Aviation Partners Group Inc
- [STC ST01783WI](https://openairdocs.org/stc/ST01783WI): Installation of Internal Wing Hardpoints. Avcon Industries Inc
- [STC ST02316LA](https://openairdocs.org/stc/ST02316LA): Installation of a Crane Aerospace & Electronics Tire Sensor Assembly. ELDEC Corporation
- [STC ST01580WI](https://openairdocs.org/stc/ST01580WI): Installation of a two place side facing divan. Aviation Fabricators Inc
- [STC ST01202WI-D](https://openairdocs.org/stc/ST01202WI-D): Modification of an existing FAA approved Collins TPR-720, TPR-900 or TPR-901 Mode S transponder installation in Part 25 Aircraft using Collins Drawing Index as listed on AML No. ST01202WI-D, latest FAA approved revision. Rockwell Collins Inc
- [STC ST00673WI-D](https://openairdocs.org/stc/ST00673WI-D): Modification of Collins VHF-22A/VHF-22B VHF COMM Receiver Transmitter with CTL-22 Control Pro Line II System Installation to a Collins VHF-22C/VHF-22D VHF COMM Receiver Transmitter with CTL-22C Control 8.33 kHz Pro Line II System installation. Rockwell Collins Inc
- [STC ST00013WI-D](https://openairdocs.org/stc/ST00013WI-D): Installation of a modified engine bleed air mixing valve regulated air source. Duncan Aviation Inc
- [STC ST00550WI-D](https://openairdocs.org/stc/ST00550WI-D): Installation of Universal Avionics, Inc., UNS-1D Flight Management System (Dual). Duncan Aviation Inc
- [STC ST00581WI-D](https://openairdocs.org/stc/ST00581WI-D): Installation of Honeywell MK VII Enhanced Ground Proximity Warning System (EGPWS). Duncan Aviation Inc
- [STC ST01182WI-D](https://openairdocs.org/stc/ST01182WI-D): Installation of a Universal UNS-1F installation. Learjet Inc
- [STC ST02005CH-D](https://openairdocs.org/stc/ST02005CH-D): Installation of Honeywell N1 Digital Electronic Engine Controls (DEEC). Honeywell International Inc
- [STC ST01142WI-D](https://openairdocs.org/stc/ST01142WI-D): Modification of a single or dual Collins TDR-94 or TDR-94D Mode S Transponder System installation with CTL-92 control head to a Flight ID capable Collins TDR-94 or TDR-94D Mode S Transponder System installation with CTL-92E control head. Rockwell Collins Inc
- [STC ST00844WI-D](https://openairdocs.org/stc/ST00844WI-D): Modification of Collins TCAS II or TCAS-94 (TCAS II) system installation with Collins TTR-920 Change 7.0 Receiver Transmitter to a Collins TCAS II or TCAS-94 OTCAS II) system installation with Collins TTR-921 or Collins TTR-4000 Change 7.0 TCAS Receiver Transmitter. Rockwell Collins Inc
- [STC ST00506DE-D](https://openairdocs.org/stc/ST00506DE-D): Installation of a Collins TCAS-4000 TCAS II system displayed on VSI/TRA indicators with dual Collins TDR-94D Mode S transponders. Learjet Inc
- [STC ST01307WI-D](https://openairdocs.org/stc/ST01307WI-D): Modification of a Collins TVI-920/TVI-920D Vertical Speed/TCAS Indicator installation. Rockwell Collins Inc
- [STC ST10278SC](https://openairdocs.org/stc/ST10278SC): Installation of a single Honeywell KGP-860 Class B Enhanced Ground Proximity Warning System (EGPWS) in accordance with the Master Document List BAS55010057, Rev. A, dated August 30, 2004, or later FAA approved revision. FAA approved Airplane Flight Manual Supplement BAS55040030, Rev. NC, dated September 1, 2004, or later FAA approved revision is required. Learjet Inc
- [STC ST01183WI-D](https://openairdocs.org/stc/ST01183WI-D): Installation of an Aft Belted Toilet with external service installation. Learjet Inc
- [STC ST01188WI](https://openairdocs.org/stc/ST01188WI): Installation of the Universal Avionics Systems Corporation Terrain Awareness Warning System (TAWS). JetCorp

All 65: https://openairdocs.org/model/learjet-55c/stcs.md

## The same model under other registry codes

Amateur-built copies and renamed makers get their own codes.

- [Gates Learjet 55C](https://openairdocs.org/model/gates-learjet-55c): 6 registered aircraft, registry code 5170706

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