# JASC 3433: Microwave Landing System

- Type: JASC system/component code (FAA)
- ATA chapter: 34 Navigation
- Title in the code table: MICROWAVE LANDING SYSTEM
- Service difficulty reports: 26
- FAA code table: https://www.faa.gov/sites/faa.gov/files/JASC_Code.pdf#page=39
- Page: https://openairdocs.org/jasc/3433

## What it covers

The instrumental landing system operating in the microwave spectrum which provides lateral and vertical guidance to aircraft having compatible avionics equipment. Typical parts are receiver, antenna, control panel, etc.

## Service difficulty reports (26)

- [SDR AALA202505159407](https://openairdocs.org/sdr/AALA202505159407), May 13, 2025: Boeing 737823. TRANSCEIVER. FAULTED. AIRCRAFT WAS GROUNDED: AT 10.000FT RED LANDING GEAR WARNING LIGHTS AND HORN CAME UP. **SUPPLEMENTAL REPORT FOR (AALA2025 (N933AN)
- [SDR AALA202505156359](https://openairdocs.org/sdr/AALA202505156359), May 13, 2025: Boeing 737823. ANTENNA. FAULTY. AIRCRAFT WAS GROUNDED: AT 10.000FT RED LANDING GEAR WARNING LIGHTS AND HORN CAME UP. **SUPPLEMENTAL REPORT FOR (AALA2025 (N933AN)
- [SDR AALA202505154554](https://openairdocs.org/sdr/AALA202505154554), May 13, 2025: Boeing 737823. ANTENNA. FAULTY. AIRCRAFT WAS GROUNDED: AT 10.000FT RED LANDING GEAR WARNING LIGHTS AND HORN CAME UP. **SUPPLEMENTAL REPORT FOR (AALA2025 (N933AN)
- [SDR AALA202505150214](https://openairdocs.org/sdr/AALA202505150214), May 13, 2025: Boeing 737823. ANTENNA. FAULTY. AIRCRAFT WAS GROUNDED: AT 10.000FT RED LANDING GEAR WARNING LIGHTS AND HORN CAME UP. **SUPPLEMENTAL REPORT FOR (AALA2025 (N933AN)
- [SDR AALA202505154106](https://openairdocs.org/sdr/AALA202505154106), May 13, 2025: Boeing 737823. ANTENNA. FAULTY. AIRCRAFT WAS GROUNDED: AT 10.000FT RED LANDING GEAR WARNING LIGHTS AND HORN CAME UP. REMOVE AND REPLACED RADIO ALTIMETER (N933AN)
- [SDR SWAA2025050768358](https://openairdocs.org/sdr/SWAA2025050768358), May 6, 2025: Boeing 7378. RECEIVER. FAULTED. SPOILERS LIGHT ILLUMINATED ON APPROACH AFTER SELECTING FLAPS 30.<[01] R&R #1 & #2 LRRA R/T PER AMM 34-33-21<BR><BR>AIRCR (N8943Q)
- [SDR SWAA2025050768375](https://openairdocs.org/sdr/SWAA2025050768375), May 6, 2025: Boeing 7378. RECEIVER. FAULTED. SPOILERS LIGHT ILLUMINATED ON APPROACH AFTER SELECTING FLAPS 30.<[01] R&R #1 & #2 LRRA R/T PER AMM 34-33-21<BR><BR>AIRCR (N8943Q)
- [SDR AALA202504087941](https://openairdocs.org/sdr/AALA202504087941), Apr 7, 2025: Boeing 7378. ALTIMETER. FALSE INDICATION. AIRCRAFT WAS GROUNDED: LANDING GEAR WARNING HORN AND GEAR UNSAFE LIGHTS ILLUMINATED MULTIPLE TIMES DURING DESCENT. REPLA (N300UB)
- [SDR AALA202504081451](https://openairdocs.org/sdr/AALA202504081451), Apr 6, 2025: Boeing 7378. ANTENNA. UNDERTORQUED. AIRCRAFT WAS GROUNDED: GEAR WARNING HORN AND RED LIGHTS ON INTERMITTENTLY ON DESCENT FROM FL230 TO ABOUT 15000. PERFORME (N300UB)
- [SDR AALA202410044170](https://openairdocs.org/sdr/AALA202410044170), Oct 2, 2024: Boeing 737823. TRANSMITTER. INOPERATIVE. AIRCRAFT WAS GROUNDED: SELECTED APPROACH MODE FOR THE ILS 25L AT LAX. LOC STARTED TO CAPTURE WHEN WE LOST BOTH FLIGHT DI (N806NN)
- [SDR AALA202402226510](https://openairdocs.org/sdr/AALA202402226510), Feb 20, 2024: Boeing 737823. ANTENNA. FAULTY. AIRCRAFT WAS NOT GROUNDED: AN EMERGENCY WAS DECLARED AND LANDED SAFELY AT LAX DUE TO: DURING CAPTURE OF ILS, LEFT SIDE F (N897NN)
- [SDR ASAA2021080435621](https://openairdocs.org/sdr/ASAA2021080435621), Aug 4, 2021: Boeing 737890. AUTOLAND SYS. FAULTED. ATTEMPTED AUTOLAND & HGS AIII, DEVELOPED A HIGH SINK RATE AND DID NOT FLARE. THEN APP/WARN IN THE HUD. DISCONNECTED A/P  (N587AS)
- [SDR UIEA2021042801014](https://openairdocs.org/sdr/UIEA2021042801014), Apr 28, 2021: Boeing 767300. TRANSCEIVER. INTERMITTENT. FO RA INTERMITTENT (NO LAND 3) REMOVED AND REPLACED RT RA XCEIVER, OPS CK OK. THIS CLEARS MDDR 146046.</P><P><SPAN></SPA (N649GT)
- [SDR AALA201909059004](https://openairdocs.org/sdr/AALA201909059004), Sep 2, 2019: Boeing 737823. TRANSCEIVER. UNRELIABLE. AIRCRAFT WAS GROUNDED: PILOT REPORTS DESCENDING THROUGH 8000 (LVL CHG, POWER IDLE). ALL RED LIGHTS ON GEAR INDICATORS AN (N816NN)
- [SDR AALA201909059016](https://openairdocs.org/sdr/AALA201909059016), Sep 2, 2019: Boeing 737823. TRANSCEIVER. UNRELIABLE. AIRCRAFT WAS GROUNDED: PILOT REPORTS DESCENDING THROUGH 8000 (LVL CHG, POWER IDLE). ALL RED LIGHTS ON GEAR INDICATORS AN (N816NN)
- [SDR AALA201909059017](https://openairdocs.org/sdr/AALA201909059017), Sep 2, 2019: Boeing 737823. ANTENNA. UNRELIABLE. AIRCRAFT WAS GROUNDED: PILOT REPORTS DESCENDING THROUGH 8000 (LVL CHG, POWER IDLE). ALL RED LIGHTS ON GEAR INDICATORS AN (N816NN)
- [SDR AALA201908319010](https://openairdocs.org/sdr/AALA201908319010), Aug 29, 2019: Boeing 737823. ANTENNA. FAULTY. AIRCRAFT WAS GROUNDED: PILOT REPORTS ON FINAL APPROACH WITH COUPLED ILS IN COMMAND B , CAPTAINS FO BARS DISAPPEARED AND  (N877NN)
- [SDR AALA2019060429002](https://openairdocs.org/sdr/AALA2019060429002), Jun 1, 2019: Boeing 757223. RADIO ALTIMETER. MALFUNCTIONED. AIRCRAFT NOT GROUNDED: PILOT REPORTS ON APPROACH 1800 RADIO ALTITUDE FLAPS 20 THROTTLES IDLE , GOT CONFIG WARNING, MASTE (N194AA)
- [SDR FDEA201902150416](https://openairdocs.org/sdr/FDEA201902150416), Feb 15, 2019: Boeing 75728A. AUTOLAND SYS. MALFUNCTIONED. PDIS 968 22-20 4737 14FEB19 TLV FACT U LOGPAGES:3011346 3011350 REPEAT EVENT: IN VNAV PATH @ 350, DECENDING TO 210, ACT  (N968FD)
- [SDR ASAA2018042624418](https://openairdocs.org/sdr/ASAA2018042624418), Apr 26, 2018: Boeing 737990ER. AUTOLAND SYS. MALFUNCTIONED. AUTOLAND NOT SUCCESSFUL, AIRCRAFT LANDED 50FT LEFT OF CENTERLINE. ACFT GROUNDED. ACCOMPLISHED FIM 22-11 TASK 825. PERFOR (N486AS)
- [SDR ASAA2018041724281](https://openairdocs.org/sdr/ASAA2018041724281), Apr 17, 2018: Boeing 737890. AUTOLAND SYS. MALFUNCTIONED. WHILE ACCOMPLISHING AUTOLAND, LAND VERIFY TEST, FOUND A FAILURE OF THE ELEVATOR PRESSURE SWITCH 1. ACFT GROUNDED. PERFOR (N577AS)
- [SDR AALA201712089032](https://openairdocs.org/sdr/AALA201712089032), Dec 4, 2017: Boeing 737823. ANTENNA. FAULTY. AIRCRAFT WAS GROUNDED: AFTER TAKEOFF AT 1000 FEET UNABLE TO ENGAGE NAVIGATION AUTO THROTTLE STAYED IN TOGA AT 5000 FT WH (N901NN)
- [SDR AALA20171204014](https://openairdocs.org/sdr/AALA20171204014), Dec 4, 2017: Boeing 737823. ANTENNA. FAULTY. AIRCRAFT WAS GROUNDED: AFTER TAKEOFF AT 1000 FEET UNABLE TO ENGAGE NAVIGATION AUTO THROTTLE STAYED IN TOGA AT 5000 FT WH (N901NN)
- [SDR UALA2010100403661](https://openairdocs.org/sdr/UALA2010100403661), Oct 3, 2010: Boeing 777222. TRANSCEIVER. FAULTY. A-T DISCONNECTED. NO LAND, 3 IND EICAS MSG AND STATUS MSGS. PERFORMED LT & RT F AUTO THROTTLE SERVO LOOP GROUND TEST , C (N206UA)
- [SDR P5CA0300961](https://openairdocs.org/sdr/P5CA0300961), Oct 7, 2003: Boeing 747236B. AUTOLAND SYS. MALFUNCTIONED. LOUD SIDE TONE IN F/O INTERPHONE. RERACKED NR 2 LRRA - TRANSCEIVER IAW MM 34-42-00, OPS CHECK OK. NOISE DISAPPEARED. (N924FT)
- [SDR CA961118014](https://openairdocs.org/sdr/CA961118014), Nov 11, 1996: Cndair CL6002B19. COUPLERS. FAILED. (CAN) BOTH CAPTAINS AND FIRST OFFICERS INSTRUMENT LANDING SYSTEM INOPERATIVE. ANTENNA COUPLERS REPLACED.

## Other codes in chapter 34

- [JASC 3400](https://openairdocs.org/jasc/3400): Navigation System (692 reports)
- [JASC 3410](https://openairdocs.org/jasc/3410): Flight Environment Data (218 reports)
- [JASC 3411](https://openairdocs.org/jasc/3411): Pitot/Static System (1,586 reports)
- [JASC 3412](https://openairdocs.org/jasc/3412): Outside Air Temperature Indicator/Sensor (254 reports)
- [JASC 3413](https://openairdocs.org/jasc/3413): Rate of Climb Indicator (157 reports)
- [JASC 3414](https://openairdocs.org/jasc/3414): Airspeed/Mach Indicator (860 reports)
- [JASC 3415](https://openairdocs.org/jasc/3415): High Speed Warning (39 reports)
- [JASC 3416](https://openairdocs.org/jasc/3416): Altimeter, Barometric/Encoder (1,256 reports)
- [JASC 3417](https://openairdocs.org/jasc/3417): Air Data Computer (1,210 reports)
- [JASC 3418](https://openairdocs.org/jasc/3418): Stall Warning System (1,641 reports)
- [JASC 3420](https://openairdocs.org/jasc/3420): Attitude and Direction Data System (772 reports)
- [JASC 3421](https://openairdocs.org/jasc/3421): Attitude Gyro and Indicating System (1,142 reports)
- [JASC 3422](https://openairdocs.org/jasc/3422): Directional Gyro and Indicating System (649 reports)
- [JASC 3423](https://openairdocs.org/jasc/3423): Magnetic Compass (101 reports)
- [JASC 3424](https://openairdocs.org/jasc/3424): Turn and Bank/Rate of Turn Indicator (153 reports)
- [JASC 3425](https://openairdocs.org/jasc/3425): Integrated Flight System (1,148 reports)
- [JASC 3430](https://openairdocs.org/jasc/3430): Landing and Taxi Aids (56 reports)
- [JASC 3431](https://openairdocs.org/jasc/3431): Localizer/VOR System (129 reports)
- [JASC 3432](https://openairdocs.org/jasc/3432): Glide Slope System (66 reports)
- [JASC 3434](https://openairdocs.org/jasc/3434): Marker Beacon System (27 reports)
- [JASC 3435](https://openairdocs.org/jasc/3435): Heads Up Display System (10 reports)
- [JASC 3436](https://openairdocs.org/jasc/3436): Wind Shear Detection System (70 reports)
- [JASC 3440](https://openairdocs.org/jasc/3440): Independent Position Determining System (261 reports)
- [JASC 3441](https://openairdocs.org/jasc/3441): Inertial Guidance System (289 reports)
- [JASC 3442](https://openairdocs.org/jasc/3442): Weather Radar System (3,442 reports)
- [JASC 3443](https://openairdocs.org/jasc/3443): Doppler System (110 reports)
- [JASC 3444](https://openairdocs.org/jasc/3444): Ground Proximity System (552 reports)
- [JASC 3445](https://openairdocs.org/jasc/3445): Air Collision Avoidance System (214 reports)
- [JASC 3446](https://openairdocs.org/jasc/3446): Non Radar Weather System (23 reports)
- [JASC 3450](https://openairdocs.org/jasc/3450): Dependent Position Determining System (106 reports)
- [JASC 3451](https://openairdocs.org/jasc/3451): DME/TACAN System (197 reports)
- [JASC 3452](https://openairdocs.org/jasc/3452): ATC Transponder System (624 reports)
- [JASC 3453](https://openairdocs.org/jasc/3453): Long-Range Navigation (LORAN) System (175 reports)
- [JASC 3454](https://openairdocs.org/jasc/3454): Visual Omnirange (VOR) System (317 reports)
- [JASC 3455](https://openairdocs.org/jasc/3455): Automatic Direction Finder (ADF) System (164 reports)
- [JASC 3456](https://openairdocs.org/jasc/3456): Omega Navigation System (9 reports)
- [JASC 3457](https://openairdocs.org/jasc/3457): Global Positioning System (635 reports)
- [JASC 3460](https://openairdocs.org/jasc/3460): Flight Management Computing Hardware System (4,690 reports)
- [JASC 3461](https://openairdocs.org/jasc/3461): Flight Management Computing Software System (68 reports)
- [JASC 3497](https://openairdocs.org/jasc/3497): Navigation System Wiring (269 reports)

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