# JASC 3422: Directional Gyro and Indicating System - Type: JASC system/component code (FAA) - ATA chapter: 34 Navigation - Title in the code table: DIRECTIONAL GYRO AND IND. SYSTEM - Service difficulty reports: 649 - FAA code table: https://www.faa.gov/sites/faa.gov/files/JASC_Code.pdf#page=38 - Page: https://openairdocs.org/jasc/3422 ## What it covers The unit operating by gyroscopic principle and driven by airflow or an electric motor, which provides heading (direction) references relative to a preset heading in degrees of the compass. Also for the flux unit detector which senses the earth's magnetic field and uses this data to correct for gyro drift. Typical parts are gyro, rotor, bearing, etc. ## Service difficulty reports (649, newest 50) - [SDR ABXA20260630296](https://openairdocs.org/sdr/ABXA20260630296), Jun 30, 2026: Boeing 767281. DISPLAY. FAULTED. ON TAXI, EADI ON CAPT'S SIDE BLANKED OUT. AIRCRAFT RETURNED TO THE GATE (BTB). PERFORMED FIM 34--22 FAULT TREE 804 SYSTE (N767AX) - [SDR CALA2026050516011](https://openairdocs.org/sdr/CALA2026050516011), May 4, 2026: Boeing 7378. ADIRU. FAULTED. LEFT IRS FAULT LIGHT ON NON NORMAL COMP DEBRIEFED WITH CREW, CHECKED FOR FAULTS IN DFCS, REPLACE L ADIRU. REF FIM 34-21 (N47280) - [SDR CALA2026050415936](https://openairdocs.org/sdr/CALA2026050415936), Apr 29, 2026: Boeing 767322. ACCELEROMETER. FAILED. ON CLIMB OUT IAS DISAREE...REPEAT WRITE UP. DEBRIEF WITH CREW,CREW STATED THAT THE IAS DIFFERENCE WAS 5 TO 10 KN FOR APP (N667UA) - [SDR CALA2025080807500](https://openairdocs.org/sdr/CALA2025080807500), Aug 7, 2025: Boeing 767322. SYMBOL GENERATOR. FAULTED. SG FAIL ON FO SIDE ADI AND HSI IN FLIGHT REMOVAL AND INSTALL THE EFIS SYMBOL GENERATOR IAW TASK 34-22-01-404-006. SOFTWA (N666UA) - [SDR ABXA20250527106](https://openairdocs.org/sdr/ABXA20250527106), May 27, 2025: Boeing 76736N. DIRECTOR. MALFUNCTIONED. AFTER TAKE-OFF, RT FLIGHT DIRECTOR DISAPPEARED TROUBLE SHOT IT AFTER 18K AND COULDN'T GET RESOLUTION SWITCHED RIGHT SIDE (N1013A) - [SDR HNAA2025033100193](https://openairdocs.org/sdr/HNAA2025033100193), Apr 5, 2025: Emb EMB145LR. DISPLAY. FAILED. DURING APPR FO MFD STARTED FLICKERING FOLLOWED BY SLIGHT ELECTRICAL ODOR DISAPATED AFTER FO MFD DIMMED TO BLACK. R&R #2 (N922AE) - [SDR SWAA2024052889012](https://openairdocs.org/sdr/SWAA2024052889012), May 22, 2024: Boeing 7378. IRS. OUT OF ALIGNMENT. CREW REPORTS; 23767; AFTER T/O NO HEADING DATA DISPLAYED ON EITHER SIDE<[01] PERFORMED IRS ALIGNMENT PER [AMM 34-21-00-8 (N1808U) - [SDR HNAA2023071750247](https://openairdocs.org/sdr/HNAA2023071750247), Jul 15, 2023: Emb EMB145LR. UNKNOWN. UNKNOWN. EICAS BLANKED OUT WITH BURNING SMELL SWAPPED EICAS AND FO MFD IAW AMM 34-22-01 PER MEL 34-1. OPS CHECK GOOD. INSPECTED E (N653AE) - [SDR DALA2023011800373](https://openairdocs.org/sdr/DALA2023011800373), Jan 17, 2023: Airbus A319114. CONTROL PANEL. FAILED. ATB DUE TO CAPTAIN'S ATTITUDE AND HEADING FAILURE. REPLACED ADIRU CONTROL DISPLAY UNIT. (N341NB) - [SDR 2023FA0000026](https://openairdocs.org/sdr/2023FA0000026), Jan 10, 2023: Cessna 501. GYRO. ERRATIC. SHORTLY AFTER TAKE OFF FROM PWA .DURING CLIMB OUT THE CREW NOTICED THAT THE PILOTS HSI WOULD NOT ERECT AND DEICIDED TO T (N393PJ) - [SDR JJBA20220919025](https://openairdocs.org/sdr/JJBA20220919025), Sep 18, 2022: Emb EMB145XR. NONE. TRIPPED. SMOKE IN COCKPIT BURNING SMELL. INSPECTED THE COCKPIT AND FOUND EICAS DISPLAY CB WAS EXTENDED. REMOVED AND REPLACED EICA (N13161) - [SDR QR9R20220909001](https://openairdocs.org/sdr/QR9R20220909001), Sep 9, 2022: Bolkms BK117C2. NONE. ILLUMINATED. DURING STARTUP THE AHRS 1 CAUTION ILLUMINATED. AVIONICS ATTEMPTED TO RESET WITH NO SUCCESS, TAKE OFF WAS ABORTED. REMOVE - [SDR QR9R20220802001](https://openairdocs.org/sdr/QR9R20220802001), Aug 2, 2022: Bolkms BK117C2. AHRS. FAILED. #1 AHRS FAILURE DURING HOVER TAXI. REMOVED AND REPLACED #1 AHRU IAW AMM 34-22-00, 4-1. FUNCTIONAL TEST AND TEST PILOT MO - [SDR CALA2022071301725](https://openairdocs.org/sdr/CALA2022071301725), Jul 13, 2022: Boeing 767322. EFIS. INOPERATIVE. RIGHT EFIS SYMBOL GEN NOT DISPLAYING TCAS TEST PATTERN ON THE L OWER MFD MEL 3422M REQUIRED. RIGHT EFIS SYMBOL GEN PLACE (N642UA) - [SDR HNAA2022062900229](https://openairdocs.org/sdr/HNAA2022062900229), Jun 28, 2022: Emb EMB145LR. NONE. NONE. PDIS 648 34-22 2613581 28JUN22 PHL CLOSE DURING FLIGHT EICAS FAILING INTERMITTENTLY FACT 28JUN22 22:09 PHL R&R #300 EICA (N648AE) - [SDR 2022F00096](https://openairdocs.org/sdr/2022F00096), Mar 3, 2022: Lear 31. NONE. FAILED. DIRECTSYN DG FAILED MID FLIGHT. PILOTS REPORTED THAT THE PILOTS (LH) HSI WAS FIXED TO A SINGLE HEADING. RENDERING THE AU (N10VJ) - [SDR HNAA2022013100058](https://openairdocs.org/sdr/HNAA2022013100058), Jan 29, 2022: Emb EMB145LR. NOT REPORTED. NOT REPORTED. PDIS 627 34-22 2753131 29JAN22 CLT CLOSE IN FLIGHT FO'S PFD LOST ATT IND WITH ALL NUMBERS SHOWING RED. SELECTED AHRS REV (N627AE) - [SDR UIEA2021110502349](https://openairdocs.org/sdr/UIEA2021110502349), Nov 5, 2021: Boeing 76733A. NONE. NONE. DURING TAXI OUT CAPTS PFD & UPPER EICAS SCREENS WENT BLANK.(

CAPT'S ADI AND UPPER EICAS CAME BACK AFTER SHUTDOWN. (N1997A) - [SDR P5CA2021110400410](https://openairdocs.org/sdr/P5CA2021110400410), Nov 5, 2021: Boeing 7673JHF. INDICATOR. FAULTED. CAPTAINS ADI BLANKED AND FADED OUT TO GREEN IN FLIGHT. EFI SWITCH BROUGHT SCREEN BACK. ELECTRIC AND OZONE SMELL LASTED F (N644GT) - [SDR UIEA2021070801494](https://openairdocs.org/sdr/UIEA2021070801494), Jul 8, 2021: Boeing 767306. DISPLAY. FAILED. CAPTAINS ADI DISPLAY FLICKERED ON OFF. SMELL OF ELECTRIC BURNING. ALSO HEARD RELAY CLICKING NOISE. TURNED BRIGHTNESS DOW (N1409A) - [SDR YV3R2021062200464](https://openairdocs.org/sdr/YV3R2021062200464), Jun 9, 2021: Robsin R44RAVENII. GYRO. DEFECTIVE. CUSTOMER REPORTED DIRECTIONAL GYRO P/N: B823-18 WILL NOT POWER UP. - [SDR 2LCF20210227](https://openairdocs.org/sdr/2LCF20210227), Feb 27, 2021: Boeing 767. ADI. ODOR. ON FEBRUARY 27, AIRCRAFT N542LA DURING THE CRUISE PHASE ON THE MIA - CJC ROUTE (UC-1307) MOMENTARILY TURNED OFF THE ADI (N542LA) - [SDR UIEA2021012100097](https://openairdocs.org/sdr/UIEA2021012100097), Jan 18, 2021: Boeing 76731B. EICAS. WARNING MESSAGE. EICAS MESSAGE "EICAS DISPLAY" AT FL370 CLIMBING TO FL390. CAPT EHSI & EADI, AS WELL AS LOWER EICAS WENT BLANK. CREW COMP (N1361A) - [SDR UIEA2021012100098](https://openairdocs.org/sdr/UIEA2021012100098), Jan 14, 2021: Boeing 76731B. EADI. MALFUNCTIONED. INITIAL LEVEL OFF AT CRUISE FL410 UPPER EICAS DISPLAY INFORMATION BLURRED ALMOST UNREADABLE FOLLOWED BY SYMBOL GENERATOR (N1361A) - [SDR 2021FA0000144](https://openairdocs.org/sdr/2021FA0000144), Jan 13, 2021: Piper PA28180. GYRO. FAULTED. AIRCRAFT WAS OPERATING UNDER 14 CFR 141 RULES IN IMC CONDITIONS WHEN THE AIRCRAFT EXPERIENCED AN INSTRUMENTATION FAILURE (N7073W) - [SDR JIKA2020122901](https://openairdocs.org/sdr/JIKA2020122901), Dec 29, 2020: Beech C99. LIGHT. SHORTED. DURING APPROACH TO KIST, THE FLIGHT CREW NOTED A STRONG SMELL AND A SMALL CLOUD OF WHITE SMOKE STARTED COMING OUT FROM T (N226BH) - [SDR UIEA2020081960778](https://openairdocs.org/sdr/UIEA2020081960778), Aug 16, 2020: Boeing 767328. HSI. SMOKE. CA HSI/MFD SHORTED OUT INFLIGHT. CAPT REPORTED SMOKE IN THE COCKPIT AND FUMES WHICH CEASED ON THE WAY BACK TO HNL. REF I (N1499A) - [SDR UIEA2020081701786](https://openairdocs.org/sdr/UIEA2020081701786), Aug 13, 2020: Boeing 767324. EADI. FAILED. CA SIDE EADI FAILURE IN FLIGHT FL 390. EFI SWITCH INEFFECTIVE REMOVED AND REPLACED CA EADI IAW AMM 34-22-03. OPS CHECK G (N663GT) - [SDR UIEA2020072951613](https://openairdocs.org/sdr/UIEA2020072951613), Jul 25, 2020: Boeing 767306. ADI. FAILED. AT CRUISE, FL 330, CAPTAIN`S ADI FLICKERED THEN FAILED. AFTER SCREEN FAILED A STRONG ODOR AND NOXIOUS FUMES BECAME APPAR (N1409A) - [SDR KCSA20200609702](https://openairdocs.org/sdr/KCSA20200609702), Jun 7, 2020: Boeing 767324. EADI. FAILED. CA ADI TURNED BRIGHT, THEN FUZZY, THEN OFF. ACRID BURNING WIRE SMELL ASSOCIATED. REMOVED AND REPLACED CAPT EADI IN ACCOR (N739DH) - [SDR KCSA2020060952603](https://openairdocs.org/sdr/KCSA2020060952603), May 26, 2020: Boeing 767324. EADI. FAILED. ADI INOP LIGHT SMOKE AND FUMES OBSERVED. REMOVED AND REPLACED CAPTAINS EADI IAW B767 AMM 34-22-03 OPS CHECK GOOD. PERFOR (N739DH) - [SDR UIEA2020051801066](https://openairdocs.org/sdr/UIEA2020051801066), May 17, 2020: Boeing 76731B. SYMBOL GENERATOR. MALFUNCTIONED. RT FLT DIRECTOR INOP ON CLIMB OUT(

REMOVED AND REPLACED RT SYMBOL GENERATOR PER B767 AMM 34-22-01. OPS CHECK GOOD.

(N1361A) - [SDR UIEA2019081805213](https://openairdocs.org/sdr/UIEA2019081805213), Aug 18, 2019: Boeing 76731B. EADI. FAILED. ELECTRICAL FUMES DETECTED SHORTLY AFTER ADI FAILURE. AFTER REMOVING AND REPLACING THE CAPTAIN`S EADI, PERFORMED SMOKE OR (N1361A) - [SDR UIEA2019071704772](https://openairdocs.org/sdr/UIEA2019071704772), Jul 17, 2019: Boeing 7673Y0. SOFTWARE. DEFECTIVE. FO SIDE TERRAIN INOP. FO SIDE WX RADAR ALSO REQUIRES WX RADAR TO BE PUSHED MULTIPLE TIMES.&NBSP;&NBSP;(

TRANSFERRED TO (N1181A) - [SDR CA190716009](https://openairdocs.org/sdr/CA190716009), Jun 29, 2019: Bell 206B. GYRO. FAULTY. (CAN) IT WAS REPORTED TO BELL:SHORTLY AFTER TAKEOFF, SMOKE STARTED TO FILL THE COCKPIT. THE PILOT TURNED OFF THE BATTERY - [SDR DXTA2019060402464](https://openairdocs.org/sdr/DXTA2019060402464), Jun 4, 2019: Cessna 560XL. COMPUTER. ERRATIC. IN CRUISE FLIGHT, HAD A HEADING MISCOMPARE. STANDBY AND RIGHT PFD DIFFERED 8DEGREES FROM LEFT PFD. RAN THE APPROPRIATE C (N685QS) - [SDR KCSA201906053106](https://openairdocs.org/sdr/KCSA201906053106), May 31, 2019: Boeing 767324. INDICATOR. SHORTED. DECLARED EMERGENCY. ELECTRICAL BURNING SMELL AND ARCING SOUND BEHIND CAPTAIN SIDE EHSI. FOUND CAPTAINS EHSI SHORTED CAUS (N739CK) - [SDR UIEA2019051504210](https://openairdocs.org/sdr/UIEA2019051504210), May 15, 2019: Boeing 76731A. SOFTWARE. FAULTY. F/O RADAR POWER BUTTON REQUIRES 2 CYCLES TO POWER.&NBSP;(

TRANSFERRED TO MDDR # 111669 PER DDG 34-43-01. CAT 'D' DUE 1 (N662GT) - [SDR YV3R2019012200083](https://openairdocs.org/sdr/YV3R2019012200083), May 14, 2019: Robsin R44. GYRO. SPINNING. CUSTOMER REPORTED DIRECTIONAL GYRO P/N: B823-2 SPINS IN FLIGHT. - [SDR 2019FA0000128](https://openairdocs.org/sdr/2019FA0000128), Apr 24, 2019: Cessna 172S. NOT REPORTED. MALFUNCTIONED. AFTER UPGRADING THE AIRCRAFT FOR ADS-B PER SB, AND UPDATING G1000 SOFTWARE, THE AIRCRAFT BEGAN LOSING MAGNETIC HEADING A - [SDR YV3R2019030100035](https://openairdocs.org/sdr/YV3R2019030100035), Feb 28, 2019: Robsin R44RAVENII. GYRO. INOPERATIVE. CUSTOMER REPORTED DIRECTIONAL GYRO P/N: B823-5 TOPPLES (INOPERATIVE). - [SDR UIEA2018100802200](https://openairdocs.org/sdr/UIEA2018100802200), Oct 6, 2018: Boeing 767306. GENERATOR. FAULTY. WEATHER DISPLAY (WXR DSPY) INTERMITTENT ON CAPT'S HSI. R&R GENERATOR ASSY-ELECTRONIC FLT IAW AMM 34-22-01, PERFORMED OPS (N1427A) - [SDR WX0A073259](https://openairdocs.org/sdr/WX0A073259), Jun 1, 2017: Doug DC983. RELAY. FAILED. DURING CLIMB OUT, LOST CA & FO FLIGHT DIRECTORS. R & R THE GROUND RELAY. (N421NV) - [SDR 4VAA20170318001](https://openairdocs.org/sdr/4VAA20170318001), Mar 18, 2017: Emb EMB145LR. DISPLAY. ODOR. STRONG ODOR OF ELECTRICAL SMOKE DURING APPROACH WITH MOMENTARY DU4 OVERHEAT ADVISORY MESSAGE. APPROACH WAS CONTINUED WHE (N824HK) - [SDR AALA20170222031](https://openairdocs.org/sdr/AALA20170222031), Feb 22, 2017: Doug DC982. GYRO. FAULTY. AIRCRAFT WAS GROUNDED. EMERGENCY DECLARED. DURING CLIMB AND INTO CRUISE THE HEADING ANNUNCIATOR ILLUMINATED MULTIPLE TIM (N7528A) - [SDR HALA2016090400342](https://openairdocs.org/sdr/HALA2016090400342), Sep 4, 2016: Boeing 7673CB. EADI. MALFUNCTIONED. AIR TURN BACK DUE TO NR 1 EHIS INOPERATIVE. REMOVED AND REPLACED THE EADI IAW AMM 34-22-03. OPS TEST PASSED. OK FOR SERV (N590HA) - [SDR HALA2016060500229](https://openairdocs.org/sdr/HALA2016060500229), Jun 5, 2016: Boeing 76733A. SYMBOL GENERATOR. MALFUNCTIONED. ETOPS SIGNIFICANT SYS - CENTER SYMBOL GENERATOR INOPERATIVE, EFIS DISPLAY GO'S BLANK WHEN ALTERNATE EFIS SELECTED. R & R (N583HA) - [SDR HALA2016021200044](https://openairdocs.org/sdr/HALA2016021200044), Feb 12, 2016: Boeing 76733A. EADI. MALFUNCTIONED. F/O ADI FLICKERING CONSTANTLY, INCLUDING LOSS OF COLOR. ALSO, FAILED TOTALLY SEVERAL TIMES. SWITCHED EFI, NO CHANGE. REP (N582HA) - [SDR HALA2016020900033](https://openairdocs.org/sdr/HALA2016020900033), Feb 9, 2016: Boeing 76733A. ADI. MALFUNCTIONED. F/O FLT DIRECTOR FLICKERS. RE-SEATED F/O ADI. GROUND OPS CHECK OK, AMM 34-22-03. ACCOMPLISHED LMP MCDP TEST 30. NO FAULT (N582HA) - [SDR ASOA20151017060C](https://openairdocs.org/sdr/ASOA20151017060C), Oct 17, 2015: Emb EMB145LR. DISPLAY. FAULTY. THE CREW REPORTED STRONG ELECTRICAL OZONE/BURNING ODOR IN THE COCKPIT BEFORE APPROACH. F/O'S MFD WENT BLANK AT THE SAME (N26545) All 649: https://openairdocs.org/jasc/3422/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 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 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) --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.