# JASC 3420: Attitude and Direction Data System

- Type: JASC system/component code (FAA)
- ATA chapter: 34 Navigation
- Title in the code table: ATTITUDE AND DIRECTION DATA SYSTEM
- Service difficulty reports: 772
- FAA code table: https://www.faa.gov/sites/faa.gov/files/JASC_Code.pdf#page=37
- Page: https://openairdocs.org/jasc/3420

## What it covers

The system components and parts which use magnetic, gyroscopic, and inertia forces to indicate an aircraft attitude and direction. Use this code for reports with insufficient information to file in JASC codes 3421 through 3425. Includes such items as the inertial reference system (IRS), etc.

## Service difficulty reports (772, newest 50)

- [SDR CALA2026100520099](https://openairdocs.org/sdr/CALA2026100520099), Oct 3, 2026: Boeing 737924ER. ADIRU. FAULTY. IRS RT FAULT FOLLOWING FIM 34-21 TASK 803, PERFORMED BITE TEST AND FAULT MESSAGES ATTATCHED IN IMAGES. REMOVED AND REPLA (N27421)
- [SDR QR9R2026082600002](https://openairdocs.org/sdr/QR9R2026082600002), Aug 26, 2026: Bolkms BK117C2. AHRS. FAILED. AHRS FAIL FLT 1. TEST FLIGHT EVAL FOUND AHRS DISC APPEARED MULTIPLE TIMES DURING A 0.2 HOVER FLIGHT. OTHER INDICATIONS W
- [SDR VNAA2026080422201](https://openairdocs.org/sdr/VNAA2026080422201), Aug 2, 2026: Cndair CL6002D24. IRU. UNSERVICEABLE. PITCH FEEL FAULT STATUS MSG IN FLIGHT AND YD2 INOP, FMS 2 DISPLAYED IRS REVERTED LOST FO'S PFD INDICATION C/A REMOVED AN (N617NN)
- [SDR YENA2026070900525](https://openairdocs.org/sdr/YENA2026070900525), Jul 7, 2026: Airbus A321271NX. INDICATOR. INOPERATIVE. FLT # 1177, BOS-LAS. (ETOPS) "FLT ATT DIRECT VIEW SYS INOP ( E-DIRECT VIEW SYSTEM )" (N2142J)
- [SDR 2026F00098](https://openairdocs.org/sdr/2026F00098), May 6, 2026: Cndair CL6002B19. AHRS. FAILED. FLIGHT OB139 VVI/CBB CANCELED FLIGHT. FAILURE DETECTED DURING PRE-FLIGHT: AHRS#1 FAILURE WITH RED FLAGS ON PFD #1 (N418AW)
- [SDR 2026FA0000307](https://openairdocs.org/sdr/2026FA0000307), Apr 30, 2026: Airbus A320214. ISIS. FAULTED. ISIS FAULT DURING TAXI (N281AV)
- [SDR DXTA2026032407359](https://openairdocs.org/sdr/DXTA2026032407359), Mar 22, 2026: Textrn TEXTRON700. ADC. FAULTED. ON TAKEOFF AT ROTATION AMBER 'BOTH ON ATT/HDG 2' PFD MSG DISPLAYED. IN CRUISE FLIGHT PILOT SIDE OUTBOARD GTC WAS ON HDG  (N874QS)
- [SDR 2A6R2026031675004](https://openairdocs.org/sdr/2A6R2026031675004), Mar 16, 2026: Urocop EC135T2. EHSI. WRONG PART. DURING REINSTALLATION OF THE EHSI (ELECTRONIC HORIZONTAL SITUATION INDICATOR), THE INSTALLING TECHNICIAN NOTED THAT THE  (N135LC)
- [SDR DXTA2026031207224](https://openairdocs.org/sdr/DXTA2026031207224), Mar 11, 2026: Emb EMB505. AHRS. FAILED. AHRS 2 FAIL AT 32000', ACCOMPANIED BY AP FAIL AND YD FAIL. PFD 2 AUTO REVERTED TO AHRS 1. AFTER SEVERAL MINUTES AHRS 2 F (N386QS)
- [SDR SIMA202602110001](https://openairdocs.org/sdr/SIMA202602110001), Feb 10, 2026: Emb ERJ170100SE. IRS. FAILED. IRS 1 FAILED WHEN ACTIVATING -DESCEND NOW- AT FL200 DECLARED EMERGENCY FOR AVONICS.MALFUTION. PERFORMED OPS CHKD OF IRS1 (N779RN)
- [SDR AALA202601081069](https://openairdocs.org/sdr/AALA202601081069), Jan 6, 2026: Boeing 737823. DEU. FAULTY. AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO: CAPTAIN SPEED TAPE AND ALTITUDE TAPE AND VVI BLANKED INFLIGHT W (N936NN)
- [SDR COEA2025121206779](https://openairdocs.org/sdr/COEA2025121206779), Dec 12, 2025: Cessna 208B. DISPLAY. FAILED. FLIGHT 4701 ENROUTE: GEG-PSC DURING FLIGHT, THE PRIMARY FLIGHT DISPLAY (G600), LEFT SIDE, FAILED. THE AIRCRAFT LANDED WI (N779FE)
- [SDR VNAA2025111711103](https://openairdocs.org/sdr/VNAA2025111711103), Nov 16, 2025: Cndair CL6002D24. COMPUTER. UNSERVICEABLE. DURING CLIMB OUT, LEFT PFD ATTITUDE INDICATOR REMOVED, RED FD, ATT ,AND HDG FLAGS DISPLAYED ON PFD, ACCOMPANIED WITH AUT (N596NN)
- [SDR SIMA20251022002](https://openairdocs.org/sdr/SIMA20251022002), Oct 22, 2025: Emb ERJ170100LR. IRU. FAULTED. IRS 1 FAIL EMERGENCY DECLARED. RAR #1 MICRO IRU IAW ERJ AMM 34-26-01 OPS CHECK GOOD (N770JM)
- [SDR AJXA2025101500037](https://openairdocs.org/sdr/AJXA2025101500037), Oct 12, 2025: Cessna 750. AOA. FAILED. PILOTS ANGLE OF ATTACK FAILED. MAINTENANCE PERFORMED BIT TEST OF AOA COMPUTER AND COULD NOT DUPLICATE THE FAULT.AIRCRAFT (N16PR)
- [SDR ABXA20251011265](https://openairdocs.org/sdr/ABXA20251011265), Oct 11, 2025: Boeing 767383. INDICATOR. FLUCTUATES. ON INITIAL CLIMB FROM KCVG STATNDY ATTITUDE INDICATOR BECAME ERRACTIC AND UNRELIABLE AC RETURNED TO FIELD AND RETURNED T (N220CY)
- [SDR 3EJA2025092200052](https://openairdocs.org/sdr/3EJA2025092200052), Sep 17, 2025: Cessna 525B. AHRS. FAILED. AHRS 1 FAILED WHILE CLIMBING THROUGH 400 FT. TROUBLE SHOT SYSTEM. SWAPPED #1 AND #2 ECU AND POWERED AVIONICS. BOTH AHRS  (N782JS)
- [SDR CALA2025091608967](https://openairdocs.org/sdr/CALA2025091608967), Sep 12, 2025: Boeing 737724. FLAG. FALSE ACTIVATION. FO PFD DISPLAYING SPD AND ALT FLAGS TESTED RIGHT ADR SYSTEM REF. TO 34-21-00, TESTED GOOD. (N23707)
- [SDR CALA2025091508917](https://openairdocs.org/sdr/CALA2025091508917), Sep 11, 2025: Boeing 767322. EADI. FAULTED. CAPT ADI BLURRED OUT AFTER REACHING CRUISE ALTITUDE PANEL INSTL-PILOTS MAIN (ELECTRONIC ATTITUDE DIRECTOR INDICATOR ONLY (N642UA)
- [SDR CALA2025081107583](https://openairdocs.org/sdr/CALA2025081107583), Aug 9, 2025: Airbus A320232. INDICATOR. FAULTED. STDBY ATTITUDE INDICATOR HAS FAILED REPLACED STANDBY ATTITUDE INDICATOR, OPS CHECK GOOD MM 34-22-24.APARTS USED: 31-4170 (N469UA)
- [SDR DALA2025060904362](https://openairdocs.org/sdr/DALA2025060904362), Jun 7, 2025: Airbus A330941. ISIS. FAILED. SHIP 3413 -DIV- TO BOS DUE TO ISIS (INTEGRATED STANDBY INSTRUMENT SYSTEM) FAILED. RESET ISIS. NO FAULTS FOUND. (7566088) (N413DX)
- [SDR 2025FA0000284](https://openairdocs.org/sdr/2025FA0000284), Apr 21, 2025: Cubcft CC19215. AIR DATA MODULE. ACTIVE. DURING A SEPT 16, 2024 FLIGHT IN RAINY CONDITIONS IN ALASKA, AT APPROXIMATELY 8:30PM, THE PIC OBSERVED THE ATTITUDE FLIG (N555BD)
- [SDR SWIA202503310001](https://openairdocs.org/sdr/SWIA202503310001), Mar 30, 2025: Cndair CL6002B19. WARNING MESSAGE. ILLUMINATED. ON DECENT RECIEVED EFIS COMP MON WITH IAS ON BOTH PFDS RAN QRH AND MSGS PERSISTEDCAPT SIDE GOT AN IAS FLAG, PITCH AND RO (N965SW)
- [SDR CALA2025021802359](https://openairdocs.org/sdr/CALA2025021802359), Feb 17, 2025: Boeing 737924ER. ADIRU. FAULTED. IRS2 FAIL IN FLT REPLACED RH ADIRU REF AMM TASK 34-21-01-400-801, OP CHECKS GOOD, PERFORMED LAND TEST REF AMM 22-11-00,  (N62894)
- [SDR CALA2025012201969](https://openairdocs.org/sdr/CALA2025012201969), Jan 18, 2025: Boeing 7378. ADIRU. FAULTED. IN FLIGHT CA SIDE INSTRUMENTS FAILED. RAN THE DISPLAY FAIL FM DID NOT WORK. FOUND MAINTENANCE MESSAGE 34-21991. NOT ACTI (N17335)
- [SDR ABXA20241207246](https://openairdocs.org/sdr/ABXA20241207246), Dec 7, 2024: Boeing 76731B. IRU. FAILED. AFTER PUSHBACK R IRS ALIGN EICAS AND DISCRETE LIGHT ILLUMINATED. PERFORMED QUICK ALIGN AND STATUS DID NOT CHANGE. AIIRCR (N1361A)
- [SDR ABXA20241004184](https://openairdocs.org/sdr/ABXA20241004184), Oct 4, 2024: Boeing 767306. IRU. FAULTED. DURING TAXI OUT EICAS MESSAGE R IRS FAULT AND DESCRETE CAME ON AC RETURNED TO THE GATE AND MTX GROUNDED AC .MTX DEFERRED (N1427A)
- [SDR QR9R2024091700001](https://openairdocs.org/sdr/QR9R2024091700001), Sep 17, 2024: Bolkms BK117C2. AHRS. WARNING LIGHT. AHRS1 WARNING REPLACED PFD AND ND, MAINTENANCE RESET PERFORMED. HOVERED OUT TO DO POWER CHECK AND AHRS1 CAME UP AGAIN. R
- [SDR DXTA2024072600011](https://openairdocs.org/sdr/DXTA2024072600011), Jul 25, 2024: Emb EMB505. AVIONICS UNIT. BROKEN. AVIONICS INTEGRATION (IAC, NIC PROC, MAU, GEA, IAPS): ON BASE LEG TO LANDING WE GOT AMBER X'S ON ENGINE, FUEL, FLAPS AND (N410QS)
- [SDR Q5QA20240627005](https://openairdocs.org/sdr/Q5QA20240627005), Jun 26, 2024: Pilats PC1245. AHRS. MALFUNCTIONED. DURING FLIGHT THE AHRS SYSTEM RESET WHILE ENCOUNTERING SEVERE TURBULENCE REQUIRING EMERGENCY ACTION. ALL SYSTEMS EVENTUA (N412MD)
- [SDR CALA2024040300962](https://openairdocs.org/sdr/CALA2024040300962), Apr 2, 2024: Boeing 737824. INDICATOR. FAULTED. REF LP 7534725, INCORRRECT MEL USED FOR DEFERRAL. CANNOT MEL STBY ATT IND DUE TO CURRENT ROUTING WX CONDITIONS. MUST FIX (N33203)
- [SDR CALA2024011700131](https://openairdocs.org/sdr/CALA2024011700131), Jan 14, 2024: Boeing 737724. ADIRU. INTERMITTENT. AIRSPEED AND ALTITUDE DISAGREE IN FLT. CAPT SIDE WAS RELIABLE. CLEARED BELOW 7000 AGL. UNIT, ADIRU, AI OFF 29-3421-9-001 (N15712)
- [SDR G1IA20231030051](https://openairdocs.org/sdr/G1IA20231030051), Oct 30, 2023: Beech C90A. VERTICAL GYRO. FAULTED. DURING CRUISE FLIGHT, AIRCRAFT PITCHED NOSE DOWN AND BEGAN A ROLL TO THE RIGHT. LOOKING AT THE PILOT'S ATTITUDE INDICATO (N930MQ)
- [SDR SWIA20230927004](https://openairdocs.org/sdr/SWIA20230927004), Sep 24, 2023: Cndair CL6002C10. UNKNOWN. UNRELIABLE. EFIS COMP MON CAUTION INFLIGHT. ROLL PITCH HDG YELLOW FLAGS. HDG RED FLAGS DISPLAYED AS WELL. FOS HSI UNRELIABLE, CAS HS (N750SK)
- [SDR M17F20230906122](https://openairdocs.org/sdr/M17F20230906122), Aug 9, 2023: Boeing 737852. ADIRU. FAILED. IRS FAULT 342 070 41
- [SDR 2023FA0000377](https://openairdocs.org/sdr/2023FA0000377), Jul 17, 2023: Lear 60LEAR. AHRS. FAILED. MONDAY 7/17/203, LEAR 60, N696RB DEPARTED KICT AND ON CLIMB THE CO PILOTS PFD DISPLAYED ERROR MESSAGES INDICATING THE AH (N696RB)
- [SDR 4DPA2023042100001](https://openairdocs.org/sdr/4DPA2023042100001), Apr 21, 2023: Emb EMB135ER. COMPUTER. FAILED. ISSUE-CREW REPORTED SPS ADVANCE AND AHRS 2 FAIL MESSAGES. AP ALSO INOP IN FLIGHT. CORR ACTION- MX TROUBLESHOT THE ISSUE  (N265JX)
- [SDR ASAA2023031542386](https://openairdocs.org/sdr/ASAA2023031542386), Mar 15, 2023: Boeing 737990ER. UNKNOWN. UNKNOWN. ON DEPARTURE SEATTLE WX RADAR ON SHOWED PWS INOP & TILT INHIBIT CLIMB CONTINUED WITH TCAS FAILURE,IRS L OUT, FLIGHT DIRE (N461AS)
- [SDR 7C7A2022122980051](https://openairdocs.org/sdr/7C7A2022122980051), Dec 28, 2022: Dhav DHC8311. ADI. FAULTED. #1 ADI ROLL AND #1 HSI HDG MISMATCH (N151RA)
- [SDR SWAA2022110767873](https://openairdocs.org/sdr/SWAA2022110767873), Nov 3, 2022: Boeing 7377H4. ADIRU. FAILED. LOST DATA ON CAPTAINS SIDE DISPLAY FAULT LEFT IRS NO 30DH / [01] R&R # 1 ADIRU PER AMM 34-21-01.OPS CHECK GOOD. AIRCRAFT (N484WN)
- [SDR DXTA2022072066350](https://openairdocs.org/sdr/DXTA2022072066350), Jul 19, 2022: Cessna 680A. SCREW. SHEARED. AFTER FRA I SWITCHED THE YAW DAMPER ON. THE FO THAT WAS PF SAID HE FELT THE RUDDERS MOVE STRANGELY AND WE RECEIVED AN AP (N507QS)
- [SDR 4EZF22071531ZV](https://openairdocs.org/sdr/4EZF22071531ZV), Jul 15, 2022: Lear 31A. EFIS. INOPERATIVE. DURING CRUISE FLIGHT FROM TNCC (CURACAO) TO TNCM (ST MAARTEN) CREW NOTICED A BURNING SMELL & NOTICED CO-PILOT'S TOP PFD  (N31ZV)
- [SDR 9JLA2022071923497](https://openairdocs.org/sdr/9JLA2022071923497), Jul 11, 2022: Cessna 560XL. AHRS. FAILED. THE FLIGHT CREW REPORTED THAT THE HEADING AND ATTITUDE ON PDF2 FAILED ON CLIMB OUT FROM AIRPORT. SELECTED HDG&ATT REV. A (N827JN)
- [SDR ASAA2022052438437](https://openairdocs.org/sdr/ASAA2022052438437), May 24, 2022: Boeing 737990ER. ADIRU. FAULTY. L IRS NOT DISPLAYING ANY INFORMATION IN FLIGHT AT FL340. NOTE- POWER INTERRUPTION ON THE GROUND DUE TO AFTER START FLOW  (N440AS)
- [SDR HNAA2022052500178](https://openairdocs.org/sdr/HNAA2022052500178), May 18, 2022: Emb EMB145LR. NONE. NONE. PDIS 626 25-00 2667912 18MAY22 RIC CLOSE FIRST OFFICER PFD GOES BLANK SEVERAL TIMES IN FLIGHT FACT 18MAY22 01:37 RIC R/R (N626AE)
- [SDR ASAA2022022437579](https://openairdocs.org/sdr/ASAA2022022437579), Feb 24, 2022: Boeing 737890. UNKNOWN. UNKNOWN. IFSD DISPLAYS OUT OF ORDER. GROUNDED - YES. AIR TURNBACK - DIVERSION TIME 83 MINUTES. T/S IAW B737-800 FIM 34-24 TASK 81 (N529AS)
- [SDR AALA202112158729](https://openairdocs.org/sdr/AALA202112158729), Dec 11, 2021: Boeing 737*. ADIRU. FAILED. AIRCRAFT WAS NOT GROUNDED: INERTIAL REFERENCE SYSTEM FAILED ON APPROACH WITH LOSS OF VERTICAL GUIDANCE, FLIGHT DECLARED  (N324SH)
- [SDR ASAA2021101236277](https://openairdocs.org/sdr/ASAA2021101236277), Oct 12, 2021: Boeing 737890. NONE. NONE. ON CLIMB OUT FMC SHOWED IRS LEFT DRIFT IRS LEFT SIDE INCREASED TO 24 WITH VERIFY POS IRS/IRS. RT IRS FUNCTIONING NORMAL. (N558AS)
- [SDR MLJA20210000250](https://openairdocs.org/sdr/MLJA20210000250), Aug 21, 2021: Cessna 310R. HSI. OUT OF LIMITS. UPON DEPARTURE THE HSI SHOWED 60 DEGREES OFF ACTUAL HEADING. RE-SLAVE ATTEMPT UNSUCCESSFUL. NOTIFIED ATC AND RETURNED TO (N3284M)
- [SDR CALA2021081801367](https://openairdocs.org/sdr/CALA2021081801367), Aug 18, 2021: Boeing 737824. ADIRU. FAILED. IRU FAIL REMOVED AND REPLACED LEFT ADIRU PER AMM 34-21-01, ALL CHECKS GOOD. PERFORMED LAND VERIFY PER AMM 22-11-00-201 A (N79279)

All 772: https://openairdocs.org/jasc/3420/reports.md

## 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 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 3433](https://openairdocs.org/jasc/3433): Microwave Landing System (26 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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